Raw materials for the manufacture of building materials. Natural building materials and raw materials for their production

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A rock

In Belarus, this type of mineral raw material is represented by numerous and diverse deposits of sand and sand-gravel mixtures, clays, carbonate rocks, gypsum, as well as natural building stone. Despite the relative cheapness of this type of raw material, its importance in the modern economy of the country can hardly be overestimated.

Sands are widespread in Belarus. The deposits of sand are confined to the Quaternary, less often to deposits of Paleogene and Neogene. They are usually of water-glacial and lake-alluvial origin; sands of aeolian genesis also lie in the south of the country. Sands are used both in the natural state and after enrichment for the production of concrete, mortar, in the glass industry and foundry.

The raw material base of building and silicate sand includes about 80 deposits (total reserves of about 350 million m 3) located throughout the country. Sands occur on the surface or close to it in the form of lenticular or stratiform deposits of various sizes. The thickness of individual deposits reaches 15 m. Deposits of building sands are confined to ozas, sandra plains, river terraces. More than 35 fields are being developed. Annual production is 7-8 million m 3.

Deposits of molding sands were identified in Zhlobin (Chetvernya deposit) and Dobrush (Lenino) districts of the Gomel region. The Chetvernya deposit is operated by the Zhlobin quarry administration, and Lenin by the Gomel mining and processing enterprise. About 0.6 million m 3 of molding sand is mined annually.

Deposits of glass sand are explored in the Gomel (Loevskoe) and Brest (City) regions. Their total reserves are 15 million m 3. Glass sands are suitable for producing window and container glass.

Sand and gravel mixtures are associated with moraine, less often alluvial deposits. Deposits of sand and gravel are widespread in the northern and central parts of Belarus. In size, they are usually small (up to 50 ha). The thickness of the productive stratum is from 1-3 to 10-20 m. The particle size distribution is unstable. The content of the main components varies as follows: pebbles - from 0 to 55%, gravel - from 5-10 to 75, sand - from 5-10 to 75, clay particles - up to 5-7%. Explored 136 deposits with total reserves of more than 700 million m 3; 82 fields are in operation. About 3 million m 3 of sand and gravel materials are mined annually. They are used mainly for the preparation of concrete and mortar.

Clays are the raw material base for the production of coarse ceramics, lightweight aggregates, and are also used as an essential component in the manufacture of various types of cement. Deposits of fusible clays are associated mainly with Quaternary deposits, and refractory clays are associated with Oligocene and Pliocene formations widespread in the south of Belarus.

Over 210 deposits of low-melting clay with a total reserves of about 200 million m 3 have been explored. More than 110 fields are being developed, 2.5-3.5 million m 3 of raw materials are annually extracted. 9 deposits have also been explored for the production of agloporite and expanded clay with total reserves of about 60 million m 3. Of these, 6 fields are exploited (production of 0.6 million m 3). Reserves of clay rocks for cement production - more than 110 million m 3.

The raw material base of refractory clays totals 6 deposits with total reserves of A + B + Cj categories of more than 50 million m 3. Deposits are represented by stratified deposits with a thickness of 1.5 to 15 m. Their depth does not exceed 7-8 m. The annual production of refractory clays is 0.4-1 million m 3.

The group of industrially valuable clay rocks of Belarus also includes kaolins found within the Mikashevich-Zhitkovich ledge of the crystalline basement. They are the weathering products of granite gneisses and gneisses. Kaolins are usually light gray and white, micaceous, mixed with hydromica and montmorillonite. 4 deposits have been identified. The deposits are cloak-like, their average thickness is 10 m, the depth varies from 13 to 35 m. Predicted resources are estimated at almost 27 million tons. Kaolins contain increased amounts of coloring iron oxides. They are suitable for the production of porcelain and earthenware products that do not require high whiteness, as well as for the manufacture of chamotte products.

Carbonate rocks, used mainly for the production of cement and lime, are represented by written chalk and marls, lying in the Late Cretaceous. They are located both in the bedrock and in the glacial rejection. A number of deposits have been explored in the areas of their shallow occurrence, mainly in Krichevsky, Klimovichsky, Kostyukovichsky and Cherikovsky districts of the Mogilev region, Volkovysk and Grodno regions of the Grodno region. Some of them (for example, Krichevskoye) are represented by writing chalk, others (Kommunarskoye) - marl, and others (Kamenka) - marl and writing chalk. The thickness of the productive stratum in the fields varies from 10-20 to 50 m with a roof depth of 1 to 25 m. The content of CaCO 3 varies from 65% in marls to 98% in crayon.

The raw material base of the cement industry includes 15 deposits with total reserves of carbonate rocks in categories A + B + Cj 720 million tons. 8 fields are being developed, on the basis of which are RUE Volkovyskcementoshifer and Krichevcementoshifer, as well as the Belarusian Cement Plant, which is developing reserves of Kommunarsky marls Place of Birth. The cement industry of Belarus is provided with carbonate raw materials for the long term.

The raw material base for lime production is based on the use of chalk. The country has 33 deposits of this mineral with total reserves of A + B + C categories of about 210 million tons. 6 deposits are being exploited.

Gypsum in a platform cover in Belarus has been known for a long time; it occurs in the form of layers, layers, interlayers, streaks and nests in the Middle, Upper Devonian and Lower Permian deposits. Relatively shallow-lying (167–460 m) thick gypsum strata were identified among the deposits of the Famennian stage of the Upper Devonian in the west of the Pripyat trough. They are confined to a raised block of the crystalline basement and form the Brinevskoe gypsum deposit. Here, up to 14 layers of gypsum are established, which are combined into four horizons. The thickness of gypsum horizons varies from 1-3 to 46 m. \u200b\u200bIn the section of the lower of them, powerful lenses of gypsum-anhydrite and anhydrite rocks are observed. The gypsum content in the productive formations varies from 37 to 95%. Gypsum reserves in the ^ + С 2 categories are 340 million tons, anhydrite - 140 million tons. It is possible to organize the production of 1 million tons of gypsum per year.

Natural building stone on the territory of Belarus is represented by various rocks of the crystalline basement (granites, granodiorites, diorites, migmatites, etc.). Two deposits of building stone (Mikashevichi and Sitnitsa) were explored in the Brest region, and a building stone deposit (Glushkevichi, Krestyanskaya Niva site) and a facing material deposit (Nadezhda Quarry) in Gomel. The largest of them is the Mikashevichi deposit. The building stone here lies at a depth of 8 to 41 m. Mineral resources are represented by diorites, granodiorites and granites. The initial stone reserves in the categories A + B + C j amounted to 168 million m 3. The field is operated in an open way; the pit depth is about 120 m. The Glushkevichi deposit is also being developed. The annual stone production at the Mikashevichi deposit is about 3.5 million m 3, the production of crushed stone is 5.5 million m 3, and at the Glushkevichi deposit it is 0.1 million m 3 and 0.2 million m 3, respectively.

At the Quarry Nadezhda facing stone deposit, the productive stratum is represented by gray and dark gray migmatites, which have good decorative properties. Depth of mineral deposits - from several tens of centimeters to 7 m; reserves of raw materials here are 3.3 million m 3.

The country has prospects for increasing the production of building stone due to the construction of a second enterprise on the basis of the Mikashevichi deposit, as well as expanding the production of facing materials at the Karyer Nadezhda deposit. Certain types of natural building stone can be used for stone casting and the production of mineral fibers. In this regard, the metadiabases of the Mikashevichi deposit are of particular interest.

End of work -

This topic belongs to the section:

INTRODUCTION TO THE GEOLOGY OF BELARUS

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I. HISTORY OF GEOLOGICAL STUDY
In the history of the geological study of the territory of Belarus, three main stages can be distinguished: (1) the beginning of the 19th-beginning of the 20th centuries; (2) the beginning of the 20th century. - 1941; (3) from 1945 to the present.

MAIN FEATURES OF THE GEOLOGICAL STRUCTURE
The territory of Belarus is located in the west of the ancient East European platform. The geological structure of such platforms is two-tiered. Here on a crystalline foundation metamorphically folded

I. GRANULITE COMPLEX
Formations of the granulite complex are spread over at least 50% of the area of \u200b\u200bBelarus. The rocks composing it are metamorphosed under conditions of a granulite facies (t \u003d 700–780 ° С, P \u003d 6–9 kbar) and are considered

AMPHIBOLITE-GEYS COMPLEX
The formation of the complex includes widespread on the territory of Belarus strata of gneisses of moderate acid and medium composition with amphibolite horizons. Areas of development of amphibolite-gneiss

AMPHIBOLITE-GEYS-SHALE COMPLEX
The complex has local distribution in the central part of Belarus. Here plagiogneisses, microgneisses, schists, amphibolites, and various

SHALE COMPLEX
This complex is limitedly distributed within the Mikashevichi-Zhitkovichi ledge of the crystalline basement in the central part of the Osnitsko-Mikashevichi volcanoplutonic belt. Will distinguish

I. ENDERBIT-CHARNOKITE COMPLEX
The rocks of the complex are widespread in the western part of Belarus, where they are closely associated with the main metamorphic rocks (crystalline schists) of the Shchuchin series and the Rudmyan sequence, forming

BLASTOMILONITE COMPLEX
In the crystalline basement of Belarus, blastomilonites are quite widespread - gneiss-shaped rocks resulting from shale, milonitization and simultaneous recrystallization of m

S.2. COMPLEXES OF BREED OF MAIN COMPOSITION
The Berezovsky complex lies in the central part of the Belarusian-Baltic granulite belt among the main crystalline schists of the Schuchinskaya series. It is represented by medium-grained metamorphoses

S.3. COMPLEXES OF BREEDS OF MIDDLE COMPOSITION
The Mikashevichy complex is developed in the southern part of Belarus and is represented by large (up to 120 km across) massifs that are closely located from each other. Arrays are stacked in an almost continuous series.

S.4. COMPLEXES OF ACID COMPOSITION
The Osmolov complex includes coarse-grained biotite, amphibole, and sometimes hypersthene-containing plagioclase-orthoclase granites and monzodiorites, which are widespread within the Belorussian-Baltic region

I. LOWER RIPHEAN, MIDDLE RIPHEAN AND UPPER RIPHEAN ERATHES
In the Riphean of Belarus (Fig. 5), the formations of all three erathemes are established (Table 2). Formations of the Lower Riphean erathema in Belarus are of limited distribution. In their

VENDA SYSTEM
Deposits of the Vendian system are represented by sedimentary (marine, continental, glacial), volcanic, and volcano-sedimentary rocks. Vendian formations are common

PALEOZOIC ERATEM 7.I. CAMBRIAN SYSTEM
Cambrian deposits occupy the extreme northwestern (slopes of the Belarusian anteclise and the Baltic syneclise) and southwestern (Podlasko-Brest depression) parts of the territory of Belarus (Fig. 6) and

ORDOVIK SYSTEM
The Ordovician deposits, like the Cambrian, are widespread in the extreme northwestern and southwestern parts of the territory of Belarus (Fig. 7). In the north-west of the country (slopes of the Belarusian Anteclise and the Baltic

SILURIAN SYSTEM
Silurian deposits, like Ordovician, have extremely limited areal distribution in Belarus - in the southwest and northwest (Fig. 9). The most complete and powerful sections of the Silurian mouth

DEVON SYSTEM
Devonian formations are widespread in Belarus - in the Orsha Depression, the Pripyat Trough (both in the Pripyat graben and the North Pripyat shoulder), in the Latvian, Zhlobin and B

S. STONE SYSTEM (CARBON)
Deposits of the coal system are much less developed in Belarus than the Devonian. They lie in two distant regions of the country - in the southeast (Pr

PERM SYSTEM
Perm deposits are spread over three fragmented areas of the territory of Belarus: in the southeast (Pripyat trough and the Bragin-Loevskaya saddle), in the south-west (Podljassko-Brest depression)

MESOZOIC ERATEM 8.I. TRIAS SYSTEM
Triassic deposits are widespread in the south-east of Belarus (the Pripyat trough and the Bragin-Loevskaya saddle) and in its south-west (the Podlask-Brest depression) (Fig. 17). In southeast

JURAS SYSTEM
Deposits of the Jurassic system are widespread in (a) southeastern, eastern, and (b) southwestern, western regions of Belarus (Fig. 19). They lie in the Pripyat trough, on the Bragin-Loevskaya and Zhlobins

CHALK SYSTEM
Deposits of the Cretaceous system are widespread throughout the southern half of the territory of Belarus (Fig. 21). They lie transgressively on rocks of different ages - from the Upper Jurassic to Archean, overlap

Cainozoic ERATEM 9.I. PALOGENIC SYSTEM
Paleogene deposits are widespread within the southern half of the territory of Belarus (Fig. 23). They lie under the formations of the quarter, and in some places Neogene, in the southeast along the valleys of the Dnieper and

NEOGEN SYSTEM
The Neogene deposits of Belarus occur in numerous spots mainly south of the line Grodno - Novogrudok - Minsk - Bykhov (Fig. 25). These are mainly terrigenous formations that have accumulated

QUARTERLY SYSTEM (KBAPTEP, ANTHROPOGEN)
The deposits of the Quaternary system in Belarus cover the formations of more ancient geological systems with a continuous cover (see Fig. 3). The thickness of deposits varies from several to 300 met

EARTH'S BARK AND UPPER Robe
Information on the deep structure of the earth's crust and the upper mantle of the territory of Belarus is obtained on the basis of mainly geophysical (gravimetric, magnetometric, seismic) data.

STRUCTURE OF CRYSTAL BASE
Three large structural-material megacomplexes are identified in the crystalline basement of Belarus, each of which corresponds to a certain stage of development of the earth’s crust in the region. It's a charnockite

STRUCTURE OF THE PLATFORM CASE 12.1. STRUCTURAL COMPLEXES AND FLOORS
As part of the platform cover of the territory of Belarus, there are several vertical, successively replacing each other in the context of structural complexes, each of which has its own space

BASIC MODERN STRUCTURES
The most important structural surface, the position of which determines the modern tectonics of the cover of the territory of Belarus, is the border of the cover and the foundation. Analysis of the nature of structural surfaces, le

EARLY ARCHAE, LATE ARCHAE, AND EARLY PROTEROZOIC EONS
The history of the geological development of the territory of Belarus during the Early Archean, Late Archean and Early Proterozoic eons is the history of the formation of the crystalline basement. In connection with

LATE PROTEROZOIC EON
In the late Proterozoic, a platform cover began to form. The first cover formations, confined to individual depressions of the basement, date from the early Riphean. These are volcanic rocks and

IS. PALEOZOIC ERA 15.1. CAMBRIAN PERIOD
In the “pre-tilrobite” (Baltic) time of the Early Cambrian era, the geographical position of the sedimentation area did not change much compared to the Valdai Late Vendian. Sedimentation was

ORDOVIK PERIOD
At the beginning of the Ordovician, after a long break, the sea again came to the territory of Belarus. As in the Cambrian period, it came in two languages \u200b\u200bfrom the west, which probably periodically connected

SILURIAN
During this period, sedimentation conditions in Belarus were close to those in the Ordovician. Shallow-water marine carbonate sedimentation continued in the extreme western regions of the country. Together

DEVONIAN
Devon is the most studied of all periods of the Paleozoic era in Belarus. This is due to the great practical importance of the formations accumulated at this time (potash and rock salts, not

STONE PERIOD
Starting from the Early Carboniferous era, the territory of the Pripyat Trough entered the post-rift syneclise stage. The subsidence rate of the territory in the Carboniferous period (0-27 m / million years) became much more

PERM PERIOD
The Early Permian era in Belarus began by sea transgression from the Dnieper-Donets trough. In the Assel age, the sea at times reached the central part of the Pripyat trough. Draft

MESOZOIC ERA 16.1. TRIASSIC
In the Early Triassic era, sagging and sedimentation occurred in southeastern Belarus (the Pripyat trough and the Bragin-Loevskaya saddle) and in its south-west (Podljassko-Brest depression). Pain

JURASSIC PERIOD
Throughout the early Jurassic era, the territory of Belarus was dry land and eroded. In the Middle Jurassic era sedimentation resumed. It was due to the formation of the largest

Cretaceous
In the Valanginian century of the Early Cretaceous, the sea from the east penetrated the territory of Belarus. It captured a very small area in the eastern part of the Pripyat Trough, on the Bragin-Loevskaya saddle and

Cainozoic Era 17.1. PALEOGENIC PERIOD
The Paleocene era in Belarus began with a long break in sedimentation. The erosion and karsting of the Upper Cretaceous carbonate deposits occurred with the formation of a weathering crust (t

NEOGENIC PERIOD
Sedimentation in the Neogene period occurred in the southern half of the territory of Belarus. Here, at the beginning of the Miocene era, there was a lowland alluvial plain with periodically boggy

QUARTERLY PERIOD
The history of the development of the territory of Belarus in the Quaternary is divided into three stages: preglacial, glacial and postglacial. The first two correspond to the Pleistocene era, the last to the Holocene

FUEL USEFUL FOSSIL
In the Pripyat Trough, 64 oil fields have been discovered. Their searches and exploration have been carried out since 1952, development - since 1965. These deposits contain 185 oil deposits, of which 183 are in Devonian deposits.

Svetlogorsk
Rechmtsa U1 Kamenets

CHEMICAL AND AGROCHEMICAL RAW MATERIALS
An important place in the country's mineral resource base is occupied by minerals, which are raw materials for use in the chemical industry and in the production of agricultural fertilizers

METAL USEFUL FOSSIL
Ore occurrences and deposits of ferrous, non-ferrous, rare and noble metals are known in Belarus, confined mainly to the crystalline basement. So, it revealed the place

AMBER AND OTHER DIY STONES
Amber finds in Belarus have been known for a long time. The vast majority of them are confined to the south-west of the country, mainly to the territory of Brest Polesie. Identified two floors of amber: lower

FRESH, MINERAL AND THERMAL UNDERGROUND WATERS
Belarus has significant resources of fresh and mineral groundwater. Fresh groundwater is associated with inter-moraine deposits of the anthropogenic sequence, Paleogene, Upper Cretaceous

CONCLUSION
This book ends with a chapter on minerals. This reflects the main ultimate goal of the study of mineral resources - the search and exploration of mineral deposits. This goal is still relevant today.

Administration of Samara city district
AMOU VPO Samara Academy of State and Municipal Administration

Faculty of Economics
Department of Cadastre and Geographic Information Technologies

Test
discipline: "Materials"
on the topic: “Raw materials for the production of ceramic building materials”

Samara, 2013
Content
Introduction ……………………………………………… .. ……. ………. ... .. …….… .3
I. General information and raw materials for the production of ceramic building materials ...................................................................... 4
II. The formation of clay materials and their chemical and mineralogical compositions …………………………………………………………………………………………… .6
2.1 The main mineral constituents of clays …………………………………. 7
2.2 Impurities ………………………………………………………………………………… ..8
2.3 The chemical composition of clays .................................................. 9

3.1 Granulometric composition of clays ………………………………………… .12
3.2 Technological properties of clay …………………………………………… 13
3.3 Classification of clay raw materials for ceramic products ……… 20
Bibliography………………………………………….…. 24
Appendices .............................................. 25

Introduction
In this test, on the topic: “Ceramic building materials”, we consider:

Ceramic production is one of the most ancient on earth. The presence of readily available material - clay - led to the early and almost universal development of the craft.
Ceramic production originated in prehistoric times after a person learned to receive and use fire. A man saw that with the help of heat it is possible to maintain the shape of objects molded from clay and make them impervious to water. They soon noticed that all clays have different properties and that different clays should be used to make certain products.
Ceramic building materials fully meet the requirements of durability and have high architectural and artistic qualities. They are resistant to aggressive environments, weatherproof and frost-resistant.
Ceramic products are most widely used in many sectors of the national economy and in everyday life. They are used as building materials - bricks, tiles, wall and floor tiles, sewer pipes, and various sanitary products. Porcelain and earthenware dishes remain by far the most common and widely used.

I. General information and raw materials for the production of ceramic building materials
Ceramic are called artificial stone materials obtained by roasting raw material molded from clay rocks. Ceramic materials used since ancient times have many advantages: raw materials for them are widespread in nature; raw can be given any shape; burnt products are strong and durable. The disadvantages of ceramic materials include: the possibility of manufacturing products of only relatively small sizes; high fuel consumption for firing; the difficulty of mechanizing work in the construction of structures made of ceramic materials.
Depending on the porosity, ceramic materials are divided into porous materials with water absorption of more than 5% and dense with water absorption of less than 5%. Both dense and porous materials can refer to coarse ceramics characterized by a painted shard, or to fine ceramics characterized by a white and uniform shard in a fracture. Coarse ceramics are used more widely in construction. Regardless of the porosity and color of the crock, ceramic materials can be unglazed and glazed. Glaze is a vitreous layer deposited on the surface of the material and fixed on it during firing. Glaze has a high density and chemical resistance.
Depending on the application in construction, ceramic materials are divided into the following groups:
wall - ordinary clay brick, hollow and porous-hollow plastic molding, corpulent and hollow semi-dry pressing, hollow plastic molding stones;
hollow stones for often ribbed ceilings, for reinforced-ceramic beams, stones for rolling;
for facing building facades - brick and front stones, carpet ceramics, small facade tiles, facade and window sill plates;
for interior cladding of buildings - tiles for wall cladding, embedded parts, floor tiles;
roofing - clay tiles ordinary, ridge, grooved and special;
ceramic pipes - sewer and drainage;
special-purpose materials - brick mold stones for sewage structures, sanitary and highly porous heat-insulating ceramics, acid-resistant products (bricks, tiles, fittings and pipes), refractory products (bricks, shaped tiles and details).
According to the established tradition, porous products of a coarse-grained structure from clay masses are called coarse ceramics, and products of a dense fine-grained structure, SA sintered shards, waterproof, such as floor tiles are called fine building ceramics.
In the production of building ceramics, mainly methods of plastic formation and semi-dry pressing are used, and casting in plaster molds (sanitary ware) is much less common.
Many scientists believe that the main strength of sintered ceramic materials is reported by mullite. Mullite 3Al 2 O 3? 2SiO 2 forms needle-shaped, prismatic or fibrous crystals with clearly distinguishable perfect cleavage.
The composition of mullite has long been the subject of debate, as a result of which researchers have come to the conclusion that the composition of mullite varies from 2Al 2 O 3? SiO 2 to 3Al 2 O 3? 2 SiO 2.
The mineral can give aggregations and clusters (adj. A). Impurities of Fe 2 O 3 and TiO 2 cause pleochism in yellowish and bluish tones. The mullite density of 3.03 g / cm 3. The size of mullite crystals is diverse: from 2 to 5 × 10 -6 m, in chamotte - up to 10 mm in length in mullite products. Also included in porcelain.

II. The formation of clay materials and their chemical and mineralogical compositions
Clay, a finely dispersed product of decomposition and weathering of a wide variety of rocks (the predominant particle size is less than 0.01 mm), is able to form a plastic mass with water that retains its shape and, after drying and firing, acquires stone-like properties.
Depending on the geological conditions, the formation of clay is divided into residual or primary (eluvial), formed directly at the location of the parent rock, and sedimentary or secondary, formed by transfer and redeposition of water, wind or glaciers to a new place. As a rule, eluvial clays are of poor quality, the parent rocks are preserved in them, they are often clogged with iron hydroxides and usually maloplastic.
Secondary clays are divided into deluvial, transferred by rain or snow waters, glacial and loess, transferred respectively by glaciers and wind. Deluvial clays are characterized by stratified strata, great heterogeneity of composition and contamination by various impurities. Glacial clays usually lie with lenses and are heavily clogged with foreign inclusions (from large boulders to small gravel). Loess clay is the most homogeneous. They are characterized by high dispersion and porous structure.
Clay rocks (clays, loams, mudstones, siltstones, shales and others) used as raw materials for the production of ceramic bricks and stones must meet the requirements of OST 21-78-88 (valid until 01.01.96), and the classification of raw materials is given GOST 9169-75 *.
The suitability of clay for brick is determined based on the mineral-petrographic characteristics, chemical composition, indicators of technological properties and rational characteristics.
2.1 The main mineral constituents of clays: kaolinite, montmorillonite, hydromica (illite).
Kaolinite (Al 2 O 3? 2SiO 2? 2Н 2 О) - has a relatively dense crystal lattice structure with a relatively small interplanar distance of 7.2 A. Therefore, kaolinite is not able to attach and firmly hold a large amount of water, and when drying clay with a high content kaolinite relatively quickly and easily give the attached water. The particle size of kaolinite is 0.003 - 0.001 mm. The main varieties of the kaolinite group are kaolinite, dikkit, nakrit. Kaolinite is the most common. Kaolinite is slightly sensitive to drying and firing, slightly swells in water and has little adsorption ability and ductility.
Montmorillonite - (Al 2 O 3? 2SiO 2? 2Н 2 О? NН 2 О) (adj. B) - has a weak connection between the packets, since the distance between them is relatively large - 9.6-21.4 A, and it may increase under the influence of wedged water molecules. In other words, the crystal lattice of montmorillonite is mobile (swelling). Therefore, montmorillonite clays are able to intensively absorb a large amount of water, hold it firmly and are difficult to give during drying, and also swell strongly when moistened with an increase in volume up to 16 times. The particle sizes of montmorillonite are much less than 1 micron (<0,001мм). Эти глины имеют наиболее высокую дисперсность среди всех глинистых минералов, наибольшую набухаемость, пластичность, связность и высокую чувствительность к сушке и обжигу.
The main representatives of the montmorillonite group are: montmorillonite, nontronite, beidelite.
Halloysite - Al 2 O 3? 2SiO 2? 4Н 2 О - includes halloysite, ferrigalloisite and metagalloisite; it is a frequent companion in kaolinites and kaolinite clays. Compared to kaolinite, halloysite has a greater dispersion, ductility and adsorption capacity.
Hydromica - (illite, hydromuscovite, glauconite, etc.) are a product of varying degrees of hydration of mica. In significant quantities, they are found in fusible clays and in small quantities in refractory and refractory clays.
Illit (hydromica) - K 2 O? MgO? 4Al 2 O 3? 7SiO 2? 2Н 2 О - is a product of long-term hydration of mica, and its crystal lattice is similar to montmorillonite. According to the intensity of bonding with water, hydromica occupy a middle position between kaolinite and montmorillonite. The particle sizes of hydromica are of the order of 1 micron (~ 0.001 mm).
2.2 Impurities.
In addition to clay components, clay rocks contain various impurities, which are divided into quartz, carbonate, glandular, organic and alkaline oxides.
Quartz impurities are found in clay in the form of silica sand and dust. They thin the clay and worsen its ductility and molding properties, although coarse quartz sand improves the drying properties of clays, and fine sand worsens them. At the same time, quartz impurities worsen the burning properties, lowering the crack resistance of the calcined products when they are cooled, and reduce the strength and frost resistance.
Carbonate impurities are found in clays in 3 structural forms: in the form of finely dispersed evenly distributed dusty particles, loose and powdery greases and in the form of dense rocky particles.
Finely dispersed carbonate impurities, decomposing during firing by the reaction CaCO 3 \u003d CaO + CO 2, contribute to the formation of a porous crock and a decrease in its strength. These small inclusions are not harmful to wall ceramics. Loose greases and accumulations during mechanical processing of clay are easily destroyed into smaller ones and do not significantly reduce the quality of products.
The most harmful and dangerous are stony carbonate inclusions larger than 1 mm, since after firing the ceramics, these inclusions remain in the shard in the form of calcined lime, which subsequently, when moisture is added from the atmosphere or, for example, when the calcined products are moistened, goes into calcium hydroxide according to the scheme
CaO + H 2 O \u003d Ca (OH) 2 + Q (heat).
Considering that the volume of hydroxide in comparison with CaO increases by more than four times, significant internal stresses appear in the shard, causing cracking. If there are many of these inclusions, a complete destruction of the ceramic product is possible.
Ferrous impurities stain ceramics in different colors: from light brown to dark red and even black. Organic impurities burn out during firing, they significantly affect the drying of the product, as they cause great shrinkage, which leads to the formation of cracks.
2.3 The chemical composition of clays.
The content of the main chemical components in the clay rock is estimated by the quantitative content of silicon dioxide, including free quartz, the sum of the oxides of aluminum and titanium, iron, calcium and magnesium, potassium and sodium, the sum of the sulfur compounds (in terms of SO 3), including sulfide.
Usually the chemical composition of fusible clays is,%: SiO 2 - 60 ... 85; Al 2 O 3 together with TiO 2 - not less than 7; Fe 2 O 3 together with FeO- no more than 14; CaO + MgO - not more than 20; R 2 O (K 2 O + Na 2 O) - not more than 7.
Comparative characteristics of the chemical composition of various clays are given in table. 1.

Table 1. The chemical composition of clays

Silica (SiO 2) is found in clays in a bound and free state. The first is part of clay-forming minerals, and the second is represented by siliceous impurities. With an increase in SiO 2 content, clay plasticity decreases, porosity increases, and the strength of calcined products decreases. The maximum content of SiO 2 is not more than 85%, including free quartz - not more than 60%.
Alumina (Al 2 O 3) is a part of clay-forming minerals and micaceous impurities. With an increase in Al 2 O 3 content, clay plasticity and refractoriness increase. Usually, based on the alumina content, the relative size of the clay fraction in the clay rock is indirectly judged. Alumina contains from 10-15% in brick and up to 32-35% - in refractory clays.
Alkaline earth metal oxides (CaO and MgO) are involved in small amounts in some clay minerals. At high temperatures, CaO reacts with Al 2 O 3 and SiO 2 and, forming eutectic melts in the form of aluminum-calcium silicate glasses, sharply reduce the melting point of clays.
Alkaline earth metal oxides (Na 2 O and K 2 O) are part of some clay-forming minerals, but in most cases they are involved in impurities in the form of soluble salts and feldspar sands. They lower the melting point of clay and weaken the coloring effect of Fe 2 O 3 and TiO 2. Alkali metal oxides are strong fluxes, increase shrinkage, densify the shard and increase its strength.
As the limit value of sulfur compounds in terms of SO 3 is taken no more than 2%, including sulfide - not more than 0.8%. In the presence of SO 3 more than 0.5%, including sulfide not more than 0.3%, in the course of testing clay rocks, methods for eliminating efflorescences and discolouration on unfired products by converting soluble salts to insoluble should be determined.

III. Technological properties of clay materials
3.1 Granulometric composition of clays is the distribution of grains in clay rock by their size. Typically, the grain composition of various clays is characterized by the data shown in table 2.
Table 2 . Clay Grain Composition

Comparing the data of the tables of chemical (Table 1) and particle size distribution (Table 2) compositions, we can conclude that they fluctuate significantly for different clays, which does not allow us to accurately establish the relationship with the properties of raw materials. However, there are certain general patterns. The low content of alumina (Al 2 O 3) with a high content of silica (SiO 2) indicates a high content of free silica, which is mainly found in the coarsely dispersed clay component and is a natural depleting additive.
Fusible clays are characterized by the highest content of SiO 2 and fluxes (R 2 O, RO, Fe 2 O 3) and the lowest content of Al 2 O 3. Here, alumina is almost completely part of clay-forming minerals, as indicated by the data in Table 2, where the content of particles less than 0.001 mm in low-melting clays is the smallest in comparison with refractory and refractory clays.
The increased content of Al 2 O 3 in clays indicates a large amount of clay substance, its greater dispersion, and therefore, greater plasticity and cohesion of the material. The high content of floodplains and in particular R 2 O (Na 2 O and K 2 O) with a low content of Al 2 O 3 indicates a low clay refractoriness. The less clay is smoother, the more refractory and sintered at higher temperatures. However, the simultaneous presence in clay of a significant amount of alkaline oxides (mainly K 2 O) with a simultaneous high content of Al 2 O 3 and a low content of other fluids can lead to high clay refractoriness and the ability to sinter at low temperatures, which makes it possible to produce a wide range of porous and sintered products. Thus, based on knowledge of the chemical-mineralogical and grain composition of the raw material, its properties can be approximately estimated.

3.2 Technological properties of clays characterize the material at different stages of its processing in the process of manufacturing products from it. The technological properties of clay rocks are studied in laboratory conditions, and the results of the study, as a rule, are checked in semi-industrial conditions. For bentonite, refractory clays and ceramic raw materials, laboratory test results are verified under industrial conditions. With the intended use of clay rocks for purposes for which there is no experience of processing in industrial conditions, as well as when studying the possibility of using raw materials that do not meet the requirements of standards and technical conditions, technological studies are carried out according to a special program agreed with interested organizations.
The most important technological properties of clay rocks that determine their use in industry are ductility, refractoriness, sintering, swelling, as well as swelling, shrinkage, shrinkage, adsorption ability, binding ability, hiding power, coloring, the ability to form stable suspensions with excess water, relative chemical inertness . These properties are determined by the processes occurring in the material when it is mixed with water, molding, drying, firing.
If dry clay powder is moistened with water, its temperature will rise. This is due to the fact that water molecules are firmly bound to clay-forming minerals and are located on them in a certain order.

Moisture absorption characterizes the ability of clay to contain a certain amount of water and hold it. With increasing dispersion of clay, its moisture capacity increases. Montmorillonite clay has the greatest moisture capacity, kaolinite - the smallest.

Swelling refers to the ability of a clay to increase its volume by absorbing moisture from air or when it is in direct contact with water. The process of swelling fades over time. Loose clay rocks swell faster than dense. Clay sanding lowers the degree of their swelling. Montmorillonite clays swell more strongly than kaolinite.

Soaking is the decay in water of large clay aggregates into smaller or elementary particles. The first stage of decomposition of a clay aggregate occurs when it swells, when water molecules, being drawn into the gaps between the grains of clay, wedge them. As the thickness of the water shell increases, the bond between the individual grains of clay loosens, and they begin to move freely in the water, being in it in a suspended state - the clay is completely soaked. To speed up the process of soaking, clay is mixed, mechanically destroying its pieces, or water is heated.
Clay soaks in water. Dense clays soak very hard. Pre-crushing and mixing during soaking accelerates this process. When soaking, water, penetrating into the pores between the clay particles, wedges them. Aggregated particles break up into smaller grains or elementary particles of clay minerals with the formation of a polydisperse system. At the same time, clay particles begin to absorb water, which is absorbed between the layers of atomic groups (“packets”) of the crystal lattice of clay particles. In this case, the particles swell, increase in volume.
Water in clay always contains a certain amount of dissolved salts, the molecules of which are dissociated into ions. The cations of these salts, being carriers of positive charges, are also surrounded by their “own” water shell and together with it can either be in the diffuse layer or on the grain surface of the clay-forming mineral, creating the so-called sorbed complex.
The processes taking place with the participation of the exchange complex of ions dramatically affect the stability (resistance to sedimentation) of clay slurry suspensions, the filtration of water in clay-containing masses during the processes of dehydration (filter pressing) of the masses or during drying. They affect the mechanical properties of plastic clay masses and dry semi-finished products.

Thixotropic hardening is the property of a wet clay mass to spontaneously restore damaged structure and strength. So, if a freshly prepared slip (clay mass of liquid consistency) is left alone for a while, then it will thicken and harden, and after mixing, its fluidity will be restored. This can be repeated many times. Clay self-hardening occurs as a result of the reorientation of clay particles and water molecules, which increases their adhesion. In this case, part of the free water goes into the bound. Clay thixotropy is of great importance in the preparation of slips, plastic dough and the formation of products.

The phenomena of thixotropic hardening of clay slip in the ceramic industry is called thickening. The amount of gelling depends on the nature of the clay, the content of electrolytes and moisture content.

Liquefaction - the property of clays and kaolins to form mobile stable suspensions when water is added. The amount of water needed to liquefy is determined by the mineralogical composition of the clay and is regulated by the addition of electrolytes. Optimum dilution, i.e., a combination of sufficient fluidity and the lowest content of the hearth, is achieved with the right choice of electrolyte and its concentration. Usually, 5% or 10% solutions of soda, water glass, sodium pyrophosphate, etc. are used as electrolytes.
Plasticity is the ability of clay to form a dough when mixed with water, which, under the influence of external mechanical forces, can take any shape without breaking the continuity and maintain this shape after the cessation of the force. The plasticity of clays depends on the grain and mineralogical compositions, as well as the clay content of the clay. With increasing dispersion of clays, their plasticity increases, montmorillonite clays have the greatest plasticity, and kaolinite has the least plasticity.

Binding ability - the property of clays to bind particles of inelastic materials (sand, fireclay), while maintaining the ability of the mass to form and give a sufficiently durable product after drying. Binding ability depends on the grain and mineralogical composition of clay.
The changes that occur in the clay mass during its drying are expressed in such properties as air shrinkage, clay sensitivity to drying and moisture-conducting ability.

Air shrinkage refers to a decrease in the linear dimensions and volume of a clay sample during drying. The amount of air shrinkage depends on the quantitative and qualitative composition of the clay substance and the moisture capacity of the clay and ranges from 2 to 10%. Montmorillonite clay has the greatest shrinkage, kaolinite - the minimum. Clay sanding lowers air shrinkage.
For the same clay, the amount of air shrinkage depends on the initial moisture content of the sample. In the first drying period, the volume shrinkage is equal to the volume of moisture evaporated from the product. In this case, first of all, capillary water evaporates from clay, which has a less strong bond with clay particles. Then the water from the hydration shells begins to move into the capillaries, the thickness of the shells decreases, and the clay particles begin to converge. Then comes the moment when the particles come into contact, and the shrinkage gradually stops. Grains of non-plastic materials can also come together due to the approach of clay particles, however, other grains prevent the clay particles from coming together together, i.e. the presence of non-plastic materials in the mass reduces air shrinkage.

The sensitivity of clays to drying affects the drying time - the greater the sensitivity of clay to drying, the more time it takes to dry to get the product without cracks. With an increase in clay content, especially montmorillonite, the sensitivity of clays to drying increases.

Moisture-conducting ability characterizes the intensity of moisture movement inside the drying product. The drying process of a clay product includes three phases: the movement of moisture inside the material, vaporization and the movement of water vapor from the surface of the product into the environment. A quantitative measure that indirectly characterizes the intensity of moisture movement inside the drying product is the diffusion coefficient. It depends on the size of the capillaries, temperature, moisture content, the type of clay mineral (in montmorillonite clays it is 10-15 times less than in kaolinite), the clay content.

In the process of heating the clays, their thermal properties are manifested. The most important of them are fire resistance, caking and fire shrinkage.

Refractoriness - the ability of clay to withstand the effects of high temperatures without melting. Clay refractoriness depends on their chemical composition. Alumina increases the refractoriness of clays, finely divided silica lowers, and coarse-grained increases. Alkali metal salts (sodium, potassium) sharply reduce clay refractoriness and serve as the most powerful fluxes, alkaline earth metal oxides also reduce clay refractoriness, but their effect is manifested at higher temperatures. According to the index of refractoriness (° C), clay raw materials are divided into three groups: 1st — refractory (1580 and higher), 2nd — refractory (less than 1580 — up to 1350), 3rd — low-melting (less than 1350).
The refractory differences of clay rocks are mainly kaolinite, hydromica, and halloysite composition or consist of a mixture of these minerals mixed with quartz and carbonates. SiO2 and А12О3 prevail in the chemical composition of refractory clay rocks, which in the best differences of refractory clays are in amounts close to their content in kaolinite (SiO2 - 46.5%, Al2O3 - 39.5%). In some differences of refractory clays, the A12O3 content decreases to 15–20%. Iron oxides and sulfides are in subordinate quantities. Harmful impurities are calcite, gypsum, siderite, compounds of Mn and Ti.
Refractory clay rocks in terms of mineral composition are not aged: they contain kaolinite, halloysite, hydromica and in the form of impurities - quartz, mica, feldspar and other minerals. Alumina is contained in them within 18–24%, sometimes up to 30–32%; silica - 50-60%, iron oxides - up to 4-6%, less often 7-12%.
Low-melting clay rocks are usually polymineral. Typically, they contain montmorillonite, beidellite, hydromica and impurities of quartz, mica, carbonates and other minerals. The alumina content in these rocks does not exceed 15–18%, silica — 80%, and the content of iron oxides is increased to 8–12%. They are also characterized by a high content of fluxes - finely dispersed impurities of ferrous, calcium, magnesium and alkaline minerals.
Sintering - the ability of clays to compact during firing with the formation of a solid stone-like shard. It is characterized by the degree and interval of sintering.

The degree of sintering is controlled by the amount of water absorption and density of the ceramic crock. Depending on the degree of sintering, clay raw materials are divided into highly sintering (a shard with no signs of burnout with water absorption of less than 2% is obtained), medium-sintering (a shard with water absorption of 2-5%) and non-sintering (a shard with water absorption of 5% or less without signs of burnout is not obtained) . Signs of burnout are deformation of the sample, visible expansion or a decrease in its total density by more than 0.05 * 10 g / cm3. The indicated water absorption values \u200b\u200bmust be stored at least at two temperature points with an interval of 50 ° C. For example, if the shard has a water absorption of 0.5% during clay firing at a temperature of 1150 ° C, and at 1100 - 2%, the decay is highly sintered, and if the same clay at a temperature of 1100:; "C forms a crock with water absorption of 4%, it is classified as medium sintering.

Clay sintering can occur at different temperatures.
etc.................

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Natural building materials and raw materials for their production

General characteristics of natural building materials, their technological properties, applications, industrial and genetic types of deposits, resource base.

The group of natural building materials includes sand and sandstone, sand and gravel, clay, carbonate rock, gypsum and anhydrite, building stones.

1. Sands, sandstones and sand and gravel

Sands - small clastic rocks of mono- or polymineral composition with particle sizes of 0.1-1.0 mm. Sandstones are cemented sands, cement can be quartz, carbonate, ferruginous, clayey. Gravel is a clastic material with fragments 1-10 mm in size. Sand and gravel mixtures contain not less than 10% of gravel fractions and not less than 5% of sand.

The main industrial genetic types of deposits.

1. Alluvial: ancient - buried valleys and terraces (Kiyatskoye - Tatarstan, Berezovskoye - Krasnoyarsk Territory); modern - floodplain and riverbed (Burtsevo - Nizhny Novgorod region., Ust-Kamskoe - Tatarstan);

2. Marine and lacquer age (Eganovskoe, Lyubertsy - Moscow region; Sestroretsk - Leningrad region).

3. Fluvioglacial (Strugs - Reds - Pskov region) 4. Eolian - dunes and dunes (Sosnovskoye - Chuvashia; Matakinskoye - Tatarstan);

The use of sand and gravel in the national economy is based on the various physical properties of these clastic rocks. More than 96% of the mined sand and gravel is consumed in construction, less than 5% is accounted for by high-purity quartz sand used in the glass, ceramic, metallurgical industries, as well as in the production of ferrosilicon, silicon carbide, etc.

Of critical importance for glass, ceramic, molding, and other pure quartz sands is the chemical composition. The silica content in them must exceed 90% .. A high silica content is a necessary condition for the sands used in the production of ferrosilicon, silicon carbide, water glass, etc., as well as for abrasive and filter sands, for molding sands used in foundry, for the production of silicate brick.

More than 60% of the quartz sand deposits are located in the European part of Russia. The major deposits are Eganovskoye and Lyubertskoye in Moscow, Tashlinskoye in Ulyanovsk, Balashoyskoye in Samara, Millerovskoye in Rostov, Tulunskoye in Irkutsk regions, etc.

They produce quartz raw materials, except for the CIS countries, Austria, Belgium, Saudi Arabia, Australia, import - Germany, Sweden, Japan.

World consumption of quartz sand is about 100-120 million per year. The share of the CIS countries (million tons) is about 36, the USA - 28, Germany - 10-14, France ~ 6, England -4, Belgium and Brazil - 3-4, Austria and Australia - 2.

In Russia in 1996, more than 6 million tons of glass and molding sands were extracted, including about 1.5 million tons of glass sands. In other CIS countries, the production of the same sand amounted to about 60% of Russian production.

Polymict building sands and sand-gravel mixtures are mainly associated with glacial deposits in the Central and North-Western parts of Russia, as well as on the plains of the south of the European part, in Western and Eastern Siberia, in the Far East, where alluvial, aeolian, and marine deposits are widely developed .

Deposits of sand and gravel are widespread, although not ubiquitous. In Russia, 1269 fields with reserves of almost 10 billion m of industrial categories were accounted for. About 600 fields with an annual production of 130-190 million m 3 are being developed.

In the northern region of the European part of Russia, raw material reserves account for 32% of the total Russian, production 36%. The North Caucasus region accounts for about 15% of the reserves and production of raw materials. In the Ural region, 17% of reserves are concentrated, production is 32%. In total, more than 80% of raw materials are mined in the European part of Russia.

Sandstones are compacted cemented, metamorphosed sands, the strength properties of which depend on the composition of cement and the nature of cementation. The composition of cement may include clay minerals, carbonates, silica, iron oxides, phosphates, etc.

They are used in the construction industry as wall stone, buta, gravel and pavers, to produce grindstones.

The genesis of sedimentary sandstones (Cheremshanskoye deposit in Buryatia, Shokshinskoye - in Karelia, in the Donbass).

Clays are finely dispersed rocks, consisting predominantly of layered aluminosilicates and having plasticity. Depending on the predominance of any component, clays are divided into allophanic, kaolinite, montmorillonite, hydromica, palygorskite.

Features of the material composition determine the most important technological properties of clays:

1. Plasticity - the ability, when mixed with a limited amount of water, to produce dough that takes any form under pressure and preserves it during drying. Plasticity is due to the mineral composition, degree of dispersion, and is characteristic of montmorillonite clays, and less so - to kaolinite.

2. Swelling - the property of clays to increase in volume upon absorption of water. The greatest swelling is montmorillonite, the least - kaolinite.

3. Shrinkage - reduction in volume during drying.

4. Sintering ability - the ability to sinter during firing into a rock-like solid - shard.

5. Refractoriness - the ability of a crock to withstand high temperatures without softening and melting. Clays are divided into refractory, refractory and fusible, the most refractory are kaolins, fusible - montmorillonite and beidellite clays.

6. Swelling during firing - an increase in volume and a decrease in the density of clay material.

7. Adsorption (absorption) properties - the ability to absorb and retain ions and molecules of various substances on its surface.

8. Water resistance

9. Relative chemical inertness.

There are 4 most important industrial groups:

Low-melting, to a lesser extent, refractory clays belong to building and coarse-ceramic. They are used in baked form for the production of building (brick, tile) and rough ceramics: clinker bricks, drainage pipes, metlakh tiles, earthenware, with accelerated firing - to obtain expanded clay and agloporite. Unbaked - as a building, binder, waterproof (during the construction of dams) material.

Refractory and refractory clays are used for the internal lining of blast furnaces, for the production of acid-resistant products, fine ceramics, as molding material in foundry.

Kaolins and kaolinite clays are highly refractory and are used for the production of fine ceramics. These are porcelain and earthenware products, items of sanitary-technical and medical equipment, household and chemical dishes. As a filler - in paper, chemical, glass, perfume industry.

Bentonites are finely dispersed clays with a high binding ability, adsorption and catalytic activity. They are used for the manufacture of flushing fluids (including drilling fluids), for the production of iron ore pellets, for the production of expanded clay, as adsorbents in the oil refining, food (wine, juice, wine, textile, and agriculture industries).

1. Residual deposits of weathering crust: kaolinite, bentonite, hydromica (Ural, Ukraine).

2. Sedimentary - marine, lagoon, lake and river (Borschevskoye - Russia, Cherkasskoye - Ukraine), glacial (Pskov, Novgorod, Leningrad regions), aeolian (south of Russia and Ukraine).

3. Volcanogenic-sedimentary - bentonites are formed in water basins (Gumbri-Georgia, Oglanlinskoye - Turkmenistan).

4. Hydrothermal - bentonites, kaolins (Sarygyuhskoye - Armenia, Askanskoye - Georgia, Gusevskoye - Primorye Russia).

5. The metamorphosed type of deposits is mudstones (Biklyanskoye - Russia, Cherkasskoye - Ukraine).

World proven resources of bentonite clays are estimated at 2000 million tons, including -800 million tons in the USA World production in 2000 amounted to 9.3 million tons, of which the United States accounted for 3.8 million tons, Greece - 0.95 million tons, Germany, Turkey, Italy - 0.5 million tons each. t Only 0.37 mln.t. was produced in Russia, which does not provide domestic needs, and means complete dependence on imports, especially in alkaline bentonites. About 70% of the reserves of high-quality bentonites of the former USSR remained outside of Russia (in the Caucasus and Central Asia).

World production of kaolin in 2000 amounted to 39.8 million tons, of which 9.45 million tons in the USA, -2.9 million tons in the Czech Republic, -2.3 million tons in the Great Britain, and South Korea -2.2 million tons in Russia - 0.04 million tons, this is extremely insufficient and Russia depends on imports, in particular from Ukraine and Kazakhstan.

3. Carbonate rocks

building carbonate rock stone

Carbonate rocks make up about 20% of the sedimentary deposits of the earth's crust and are represented by the following varieties.

Limestones are sedimentary rocks consisting mainly of calcite (CaCO 3) with an admixture of dolomite (Ca, Mg (CO 3) 2), sand and clay particles. With a dolomite content of 20-50%, dolomite limestone.

Shell limestones consist of fragments of shells cemented with carbonate or clay-carbonate cement - light porous rocks.

Chalk is a rock consisting of 60-70% of the smallest residues of skeletal formations of planktonic organisms and 30-40% of fine-grained powdery calcite.

Mergels are fine-grained sedimentary rocks that are transitional from limestones and dolomites to clayey rocks and contain 50-70% of calcite or dolomite or a mixture thereof and 20-50% of clay-sand material.

Dolomites - carbonate sedimentary rocks consisting (not less than 90%) of the dolomite mineral (Ca, Mg (CO 3) 2).

Marbles and marbled limestones are carbonate rocks that have undergone recrystallization as a result of regional or contact metamorphism.

The main industries and volumes of consumption of carbonate rocks are as follows (in%): production of building and facing stone - 60, cement industry - 20, metallurgical industry - 10, lime - 5, refractory - 2, agriculture - 1, the rest - 2.

For the production of building and facing stones, limestones, dolomites, marbles are used, which are distinguished by their decorativeness and good polishability, high physical and mechanical properties - hardness, strength. From carbonate rocks, rubble stone, crushed stone, crumbs, piece and facing stones are obtained. About 220 million tons of carbonate rocks are spent annually on the needs of civil, industrial and road construction alone.

In the cement industry, limestones, chalk, marls, or mixtures thereof with certain ratios AI2O3, Si0 2, Fe 2 0 3 and CaO are widely used. Low-magnesian carbonate rocks containing not less than 40% CaO and not more than 3.5% MgO are considered to be conditioned.

Portland cement, alumina cement and many other types of binders are made from carbonate rocks. The raw materials for the production of Portland cement are various carbonate rocks, among which limestones, chalk and marls play the predominant role. Of particular value are marls-straights. Portland cement is used for the manufacture of concrete.

In the metallurgical industry, pure carbonate rocks serve primarily as fluxes. They convert to waste slag and harmful impurities .. A significant amount of dolomites is used as raw material for the production of magnesium and refractory material in metallurgy.

The lime industry for the production of hydraulic, air, slow-extinguishing and other types of building lime consumes mainly limestone and chalk.

Pure limestones are used in the chemical industry for the production of soda, calcium carbide, caustic potassium and sodium, chlorine, etc. In the food industry, they are used to clean sugar. In agriculture, soft limestones and chalk are used for liming podzolic soils. A significant amount of carbonate raw materials is used in glass, paper, paint and varnish, rubber and other industries.

Industrial genetic types of deposits:

1. Sedimentary - marine represented by limestone dolomites, marls and chalk. According to the conditions of formation, biogenic, chemogenic and mixed are distinguished. Industrial limestone deposits - on a significant part of the East European and Siberian platforms, in the Urals, in Kuzbass, Altai, Krasnoyarsk Territory, the Caucasus, Rostov Region (Zhirnovsky deposit); Dolomites - in the Urals (Sukhorerechenskoe) in the Yenisei Ridge, the Small Khingan Range; chalk - Volskaya group (Saratov region); Mergel - Novorossiysk group of deposits;

2. Metamorphosed - marbles and marbled limestones (Belogorskoye in Karelia; Kibik -Kordonskoye in the Sayan Mountains).

The global consumption of carbonate raw materials is more than 5 billion tons. in year. The largest consumers are the USA, Russia, Japan.

The resources of carbonate rocks in Russia are huge. They are distributed extremely unevenly on the territory. About 50% of the reserves are concentrated in the European part. The least affluent areas are Karelia and the Murmansk region, as well as the Tyumen, Omsk, Kamchatka and Kaliningrad regions.

4. Gypsum (CaSO 4 2H 2 O) and anhydrite (CaSO 4)

Plaster and anhydrite are most common among saline formations and are similar to each other. Gypsum is a layered or massive rock of a granular structure of white color. Gypsum crystals are transparent, granular aggregates are colored with impurities in different colors; fine-grained transmission unit - alabaster; fine fiber - selenite. Low hardness, easy to process.

When calcined, gypsum loses crystallization water. At t \u003d 100-180 ° C, they pass into hemihydrate (CaSO 4 · 0.5H 2 O); at t \u003d 200-220 ° C - artificial anhydrite, soluble in water; at t \u003d 800-1000 ° С - estrich gypsum, at t \u003d 1600 ° С - in CaO burnt lime.

Anhydrite from gypsum has a high density and strength and has significantly worse astringent properties.

The main property of gypsum, which determines its industrial use, is the ability to lose crystallized water when heated and to give a plastic mass when mixed with water, gradually hardening in air and turning into a durable artificial stone.

Of gypsum binders, building gypsum is most widely used for plastering and decorating, the manufacture of building structures. To obtain building gypsum, natural gypsum is crushed and ground, and then calcined in rotary or shaft furnaces at 130-180 ° C for 1.5-2 hours. When processing natural gypsum with saturated steam under pressure, high-strength semi-aquatic gypsum is obtained - an astringent with a short setting and hardening time, which has increased mechanical strength and is used as molding and medical gypsum. The first is used for the manufacture of work forms in porcelain and faience and ceramic production, for casting metals and alloys, and for performing various sculptural works; the second is used in surgery and dentistry. Estrich-gypsum slowly combines with water and becomes an astringent used for the manufacture of tiled and seamless floors, mortars, window sills and steps, artificial marble, etc. Gypsum is widely used in the production of various cements. Gypsum slag cement. successfully used in the construction of underground and underwater structures exposed to leaching and sulfate aggression.

In the production of gypsum binders and as additives to cements, more than 90% of the total gypsum and anhydrite is consumed. In a small amount, gypsum and anhydrite are used as facing and semi-precious stones, fluxes in the smelting of oxidized nickel ores, in the chemical industry, agriculture and in the manufacture of paper.

Gypsum and anhydrite are formed in saline basins at the initial stages of salt deposition.

Industrial genetic types of deposits:

1. Sedimentary: syngenetic - precipitation from solutions (Novomoskovskoye in the Tula region, Pskov region, Kamenomostskoye - the North Caucasus - Russia, Transnistrian deposits - Ukraine); epigenetic - during hydration of anhydrite (Zalarinskoye in the Irkutsk region, in the Donbass, Zvozskoye in the Arkhangelsk region);

2. "Gypsum hats" - residual products of dissolution of rock salt (Brinevskoye deposit - Belarus):

3. Infiltration - upon dissolution and redeposition of gypsum scattered in the rocks (North Caucasus, Central Asia, Kazakhstan).

Large reserves of gypsum have been explored in the world - about 7 billion tons, including more than 5 in Europe, about 1 in the USA, and 0.5 billion tons in Canada.

The leading exporters of gypsum and anhydrite are Canada, Thailand, Spain. The main importers are the USA and Japan.

Explored reserves of gypsum, anhydrite and gypsum-bearing rocks are available in all CIS countries except Belarus; 75% of the reserves are concentrated in Russia.

The reserves of gypsum and anhydrite in Russia are unevenly distributed: 95% of them are in the European part and only 5% are in the Asian part. Most of the gypsum raw materials in Russia (58%) are located in the Central region, where the largest of the explored and developed deposits are located.

Of the total production of gypsum anhydrite rocks in the CIS countries, 59% are in Russia,

5. Natural building and decoration stones

Building stones represent an extensive group of non-metallic minerals, which occupy one of the first places in construction production in terms of consumption. Being inert materials, they include sawn (wall) and facing stones and, along with sand and sand and gravel mixtures, make up the main complex of natural building materials used in their natural state without the use of thermochemical treatment.

Natural building stones are igneous, metamorphic and sedimentary rocks of various compositions. In most cases, the mineral composition of rocks is not significant, the physical and mechanical properties of the rocks are determining. Carbonate rocks, granites and similar rocks are used in the largest quantities. Less commonly used are gabbroids, basaltoids, and sandstones.

Inert building materials obtained from the processing of building stones are used as aggregates of heavy concrete.

Application as building stones depends on their physical and technological properties. The most important are the strength and durability, depending on the mineral composition of the rock, structural and texture features, fracture, porosity, etc. The most resistant rocks are: quartzites, granites, syenites, diorites. Carbonate rocks - limestones, dolomites and marbles, despite the relatively low abrasion resistance, are characterized by compressive strength and are used for interior and exterior decoration of buildings. Fine-grained rocks are usually more durable than coarse-grained. To assess the suitability of the rock as a building stone, a set of special laboratory tests is carried out, including determination of volumetric mass, density, porosity, water absorption, frost resistance, compressive strength, tensile, bending, abrasion, viscosity, etc. Depending on the application, workability is additionally studied. viscosity, refractoriness, polishability, color fastness, etc.

Building stones are used as follows:

Rubble stone (rubble) - a stone of irregular shape with a size of 140 mm, is used for laying foundations, in the construction of massive structures (dams, dams, etc.).

Piece stones - products of regular geometric shape with machined surfaces, are used as curbs, paving stones for road surfaces, architectural and decoration parts, steps, basement and facing products, shafts and millstones - industrial products.

Saw stones - standard-sized blocks are cut with disk cutters directly in the rock mass and are used as wall material.

Crushed stone is the most popular product used as aggregate for concrete and asphalt concrete for filling railway tracks and highways.

Natural facing stones represent a specific group of building materials, the industrial value of which is determined primarily by their decorative properties. Along with this important property of facing stones is mechanical strength, the ability to accept various types of surface treatment and weather resistance - weather resistance.

Rocks of various origin are used as facing stones: intrusive - granites, syenites, diorites, gabbro-norites, labradorites; effusive - basalts, diabases, andesites, porphyries, porphyrites, volcanic tuffs; metamorphic - marbles, quartzites; sedimentary - limestones, dolomites, travertines, gypsum, sandstones, conglomerates and breccias. The most widely used granites and marbles.

In Russia, the Baltic Shield (Kola Peninsula, Karelia) is a large mining area of \u200b\u200bhigh-quality igneous and metamorphic rocks: granites of various colors and patterns used as facing and monumental stones. Another large area is the Urals: granites, gabbros, jaspers, marbles. Numerous deposits of igneous and metamorphic rocks are known in Altai, Sayan, Transbaikalia, Primorsky Krai (granites, basalts, gabbro-diabases, tuffs). Significant reserves of various building stones are also possessed by Ukraine, Kazakhstan, and Armenia.

The European part and Western Siberia have numerous deposits of sedimentary carbonate rocks, sandstones, conglomerates

On the territory of Russia, more than 1000 deposits of building stones with reserves in the industrial categories of about 20 billion m 3 were recorded. More than 500 fields are being developed. About 100 million m 3 of building stones are mined annually.

Sawed limestone reserves in Russia are approximately 110 million m 3. More than 100 thousand m 3 are mined per year.

The leading country in the world in the production and use of facing materials and products is Italy, which exports a significant part of marble to various countries. Deposits of rare varieties of marbles are located in Belgium and France. Highly decorative granite is mined in Sweden, Spain, Brazil.

In Russia, 146 deposits of facing stones with reserves for industrial categories of 536 million m were accounted for. Of these, about 40 deposits are developed with an annual production volume of 500-600 thousand m 3. In the rest of the CIS countries, about 300 deposits with reserves of about 900 million m 3 were recorded. At 165 developed fields, 3.5 million m of facing stones are mined annually.

Literature

1.Agafonov G.V., Volkova E.D. et al. “Fuel and Energy Complex of Russia: Current State and Look into the Future”. Novosibirsk, Science, Siberian Publishing Company RAS, 1999, 312 pages.

2. Eremin N.I. Non-metallic minerals: Textbook - M. Izd-vo MSU. 1991.-284 p.

3. Karyakin A.E., Strona P.A. and other Industrial types of non-metallic mineral deposits. M. Nedra. 1985.

4. Tatarinov I. K., Karyakin A.E. and others. The course of deposits of solid minerals L. Nedra, 1975.

5.Yakovlev P.D. Industrial types of ore deposits. M. "Nedra", 1986. Textbook. 358 sec

Additional

1 Vaganov V.I., Varlamov V.A. Diamonds of Russia: mineral resource base, problems, prospects. // Mineral resources of Russia. Economics and Management - 1995- No. 1.

2. Baibakov N.K., Righteous N.K., Staroselsky V.I. and others. Yesterday, today and tomorrow, the oil and gas industry of Russia. -M.: Publishing house of the IGiRGI, 1995.

3. Benevolsky BI, The raw material base of gold in Russia on the path of development, problems and prospects. Mineral Resources of Russia, journal, 2006, No. 2, pp. 8-16.

4. Butova MN, Zubtsov IB Problems of the development of the raw material base and indium production // Mineral resources of Russia. - 199 p.

5. Gold G.S. Mineral resources: The social challenge of time. -M.: Trade Unions and Economics, 2001.-407 p.

6. Dvornikov V.A. Economic security. Theory and reality of threats. - M .: Nedra, 2000.

7. Zaydenvarg V.E., Novitny A.M., Tverdokhlebov V.F. Coal resource base of Russia: state and development prospects // Coal. - 1999. - No. 9.

8. Kavchik B.K. Extraction of alluvial gold in the twenty-first century. Mineral resources of Russia, magazine, 2007, No. 2, p. 43-49.

9. Kozlovsky E.A. Mineral and raw material problems of Russia on the eve of the twenty-first century, Moscow, Moscow State University for the Humanities, 1999, 402 p.

10. Kozlovsky E.A. Russia: Mineral Resources Policy and National Security.- M. Publishing House of MGGU 2002. 856 p.

11. Kozlovsky E.A., Schadov M.I. Mineral and raw materials problems of national security of Russia. - M.: Publishing House of Moscow State University, 1997.

12. Kochetkov A.Ya. , Kuzmin A.V., Vasilivetsky A.A., Foreign gold mining companies in Russia. Mineral Resources of Russia, journal, 2007, No. 2, pp. 50-57.

13. Kochetkov A.Ya. Change of leader among the gold mining regions of Russia, Mineral resources of Russia, magazine, 2004, No. 4, p. 65-71.

14. Krivtsov A.I., Benevolsky B.L., Minakov V.M. National Mineral Resources Safety (introduction to the problem). - M.: TSNIGRI, 2000.

15. Krivtsov A.I. Mineral resources base at the turn of the century - retrospective and forecasts. Ed. 2nd, supplemented. - M .: Geoinformmark CJSC. 1999 .-- 144 p.

16. Kuzmin A.V. Russian gold mining industry-consolidation processes. Mineral Resources of Russia, journal, 2004, No. 4, p. 58-64.

17. Laverov N.P., Kontorovich A.E. Fuel and energy resources and Russia's exit from the crisis. G. Economic strategies. - 1999. No. 2.

18. Laverov N.P., Trubetskoy K.I. Mining in the system of earth sciences // Herald of the RAS. T. 66. - 1996. - No. 5.

19. Lazarev V.N. On the reproduction of the mineral resource base of non-ferrous and alloying metals // Mineral Resources of Russia. Economics and Management. - 2001.-№ 3. - S. 52-60

20. Lazarev V.N. On the long-term forecast for the development of the raw material base of copper. No. 2, Mineral resources of Russia. 2007 p.6-12

21. Mashkovtsev G.A. Uranium reserves and production: state and prospects // Ores and metals. --2001. --№ 1. 256

22. Melnikov N.N., Busyrev V.N. The concept of resource-balanced development of the mineral resource base. // Mineral resources of Russia. Economics and Management - 2005-No.2-p. 58-63.

23. Mineral resources of the world. - M .: IAC "Mineral", 2004.

24. Mineral resources of the world. Chronicle of current events.// MNR of Russia. IAC “Mineral” - M., 2002

Posted on Allbest.ru

...

Natural raw materials (minerals)

Raw materials are starting materials or mixtures that
processed into building materials or
products.

The main raw materials for production
Building materials are natural materials.

Natural inorganic raw materials (nonmetallic minerals)

This species includes widespread
in nature rocks with
essential chemical and mineral
composition, many favorable physicochemical properties and attractive
appearance.

Mountain
breed
Chemical
composition
Application
Sand
Silica (SiO2)
Aggregate in concrete,
solutions
Raw materials for obtaining
glass alloys
Clay
Aluminosilicates (SiO2,
Al2O3)
One of the raw materials
components for
receiving clinker
Raw materials for obtaining
ceramic
products
Granite and others
erupted
breeds
Silicates and
aluminosilicates
Crushed mountain
rocks (crushed stone,
sand)
Raw materials for
concrete aggregates
and solution
Diabase
Silicates and
aluminosilicates
Crushed stone
Raw materials for obtaining
stone melts
Limestone
Calcium carbonate
(CaCO3)
One of the raw materials
components for
receiving clinker
Raw materials for obtaining
air lime
Marble
Calcium carbonate
(CaCO3)
Decorative crushed stone
sand
Raw materials for
decorative concrete
and solutions
Gypsum stone
Bisulfate
calcium
(CaSO4 · 2H2O)
Decoration tiles
Raw materials for obtaining
gypsum binders

Natural Organic Raw Materials

Wood of various species:
- timber materials (logs);
- lumber (timber, boards);
- wood products (boards for
floors, skirting boards, window and
door blocks, parquet)
-wood products (plywood,
Particleboard and fiberboard, wood-layered
plastics
glued wooden
constructions
Oil, gas, coal, peat:
-organic binders for
asphalt concrete, the main component
roofing and waterproofing
materials;
polymers (binders for plastics),
linoleums, fiberglass;
-component of composite materials;
-polymer-cement concrete;
-modifying additives for
building mixtures;
-base for varnishes and paints;

Environmental problems in the production of building materials.

Use of production waste.

Some of the environmental challenges:
maximum use of natural
raw materials and waste generated during its extraction and
recyclable.
waste management of other industries.

Mining and processing waste
breeds:
From them you can get
Sawing and processing waste
surface
Decorative slabs of marble pieces
and granite slabs (breccia type)
Crushed stone production waste:
Crushing on aggregates;
sieving with artificial
sand (particle sizes from 0.16 to 5 mm)
(particles with a size of 5-70 mm)
Stone flour milling
(asphalt concrete filler, mastics,
plastics)
Wood processing waste:
Wood shavings, chips, non-wood
Particleboard, fiberboard, fiberboard, wood concrete
Sawdust
Filler in plastics,
gypsum concrete products
Thermal energy waste:
Ash
Additives in concrete and mortar mixes;
Raw material component for
clinker production;
Toxins
Placeholders;
Active mineral supplement
cement;

10. The use of waste has not only environmental, but also economic aspects:

in those regions where there is no or insufficient natural raw materials,
the raw material base of construction production is expanding
materials;
the cost of building materials is reduced, as
transportation costs are eliminated or reduced
natural raw materials from other regions;
solves the problem of recycling industrial waste,
eliminates the need for polygon devices for their
storage.

11. Problems of environmental pollution

Sources of pollution
Raw materials (waste)
Technology
Heavy metals
Aerosols
Radioactivity
Radioactivity
Dust
(silica)
Flushing
heavy
of metals
Gases
Finished product
Selection
phenol
formaldehyde

12. Basic principles of production

The purpose of any technology is to obtain a specific material or product
forms, of certain sizes with given stable (constant)
properties.
Raw materials → processing → Finished material (product)
Mechanical technology - in the process of processing the feedstock is not
its composition, structure, and properties change; shape, size,
surface condition (texture) (these technologies are used to
obtaining products from natural stone materials, from wood);
Physico-chemical technology - in the manufacture of building materials
or products under the influence of technological factors (temperature,
pressure) various physicochemical processes occur, as a result
which change the composition, structure and properties of raw materials

Ministry of Science and Education of Ukraine

Kiev National University of Construction and Architecture

Department of building materials science

Abstract on the topic: "The use of secondary products in the manufacture of building materials"

1. The problem of industrial waste and the main directions of its solution

a) Industrial development and waste storage

b) Classification of industrial waste

2. Experience in the use of waste metallurgy, fuel industry and energy

a) Cementing materials based on slag and ash

b) Slag ash aggregates

c) Fused and artificial stone materials based on slag and ash

d) Ashes and slags in road building and insulating materials

e) Materials based on sludge from metallurgical industries

f) The use of burnt rocks, coal processing waste, mining and concentration of ores

3. Experience in the use of waste from chemical-technological production and wood processing

a) The use of slags electrothermal production of phosphorus

b) Materials based on gypsum-containing and ferrous waste

c) Materials from the waste of wood chemistry and wood processing

d) Disposal of own waste in the production of building materials

4. References

1. The problem of industrial waste and the main directions of its solution.

a) Industrial development and waste storage

A characteristic feature of the scientific and technological process is an increase in the volume of social production. The rapid development of productive forces causes the rapid involvement in the economic turnover of an increasing amount of natural resources. The degree of their rational use remains, however, generally very low. Every year, humanity uses about 10 billion tons of mineral and almost as many organic raw materials. The development of most of the most important minerals in the world is faster than their proven reserves are growing. About 70% of industrial costs are for raw materials, materials, fuel and energy. At the same time, 10 ... 99% of the feedstock is converted into waste discharged into the atmosphere and water bodies polluting the earth. In the coal industry, for example, approximately 1.3 billion tons of overburden and mine rocks and about 80 million tons of coal processing waste are generated annually. Annually, the output of slag from ferrous metallurgy is about 80 million tons, non-ferrous 2.5, ash and slag from thermal power plants 60 ... 70 million tons, wood waste about 40 million m³.

Industrial waste actively influences environmental factors, i.e. have a significant effect on living organisms. This primarily relates to the composition of atmospheric air. Gaseous and solid wastes enter the atmosphere as a result of fuel combustion and various technological processes. Industrial waste actively affects not only the atmosphere, but also the hydrosphere, i.e. water environment. Under the influence of industrial waste concentrated in dumps, slag dumps, tailings, etc., the surface runoff in the area where industrial enterprises are located is polluted. The discharge of industrial waste ultimately leads to pollution of the waters of the oceans, which leads to a sharp decrease in its biological productivity and adversely affects the climate of the planet. Waste from industrial activities negatively affects soil quality. In the soil, excessive amounts of compounds harmful to living organisms, including carcinogens, accumulate. In the contaminated "sick" soil, degradation processes are under way, the vital activity of soil organisms is disrupted.

A rational solution to the problem of industrial waste depends on a number of factors: the material composition of the waste, its state of aggregation, quantity, technological features, etc. The most effective solution to the industrial waste problem is the introduction of non-waste technology. The creation of non-waste production is carried out due to a fundamental change in technological processes, the development of closed-loop systems that ensure the reuse of raw materials. With the integrated use of raw materials, industrial waste from some industries is the source of raw materials from others. The importance of the integrated use of raw materials can be considered in several aspects. Firstly, waste disposal allows solving environmental problems, freeing up valuable land occupied by dumps and sludge storages, and eliminating harmful emissions into the environment. Secondly, the waste largely covers the needs of a number of processing industries for raw materials. Thirdly, with the integrated use of raw materials, the specific capital costs per unit of production are reduced and the payback period is reduced.

Of the industries that consume industrial wastes, the construction industry is the most capacious. It has been established that the use of industrial waste can cover up to 40% of the construction needs for raw materials. The use of industrial waste makes it possible to reduce costs for the manufacture of building materials by 10 ... 30% compared with their production from natural raw materials, saving capital investment reaches 35..50%.

b) Classification of industrial waste

To date, there is no comprehensive classification of industrial waste. This is due to the extreme diversity of their chemical composition, properties, technological features, conditions of formation.

All industrial waste can be divided into two large groups: mineral (inorganic) and organic. Of greatest importance for the production of building materials are mineral waste. The prevailing share of all waste produced by the mining and processing industries falls on their share. These wastes are more studied than organic.

Bazhenov P.I. It is proposed to classify industrial wastes at the time of their separation from the main technological process into three classes: A; B IN.

Class A products (quarry residues and residues after mineral processing) have chemical and mineralogical composition and properties of the corresponding rocks. The scope of their application is due to the state of aggregation, fractional and chemical composition, physical and mechanical properties.

Class B products are artificial substances. They are obtained as by-products as a result of physicochemical processes occurring at ordinary or often high temperatures. The range of possible uses for this industrial waste is wider than Class A products.

Class B products are formed as a result of physicochemical processes occurring in dumps. Such processes can be spontaneous combustion, decomposition of slag and the formation of powder. Typical representatives of this class of waste are burned rocks.

2. Experience in the use of waste metallurgy, fuel industry and energy

a) Cementing materials based on slag and ash

The bulk of the waste in the production of metals and the combustion of solid fuels is formed in the form of slag and ash. In addition to slag and ash, in the production of metal in large quantities, waste is generated in the form of aqueous suspensions of dispersed sludge particles.

Valuable and very common mineral raw materials for the production of building materials are burnt rocks and coal processing waste, as well as overburden and ore dressing waste.

The production of binders is one of the most efficient areas of slag application. Slag binders can be divided into the following main groups: slag Portland cement, sulfate-slag, lime-slag, slag-alkaline binders.

Slag and ash can be considered as a largely prepared raw material. In their composition, calcium oxide (CaO) is bound in various chemical compounds, including in the form of dicalcium silicate - one of the minerals of cement clinker. The high level of preparation of the raw material mixture when using slags and ashes provides an increase in the productivity of furnaces and fuel economy. Replacing clay with blast furnace slag allows to reduce the content of lime component by 20%, to reduce the specific consumption of raw materials and fuel in dry clinker production by 10 ... 15%, and also to increase the productivity of furnaces by 15%.

The use of low-iron slag — blast furnace and ferrochromic — and the creation of reducing conditions for smelting produce white cements in electric furnaces. On the basis of ferrochrome slag by oxidation of metallic chromium in the melt, clinkers can be obtained using cement with a uniform and stable color.

Sulphate-slag cements are hydraulic binders obtained by co-fine grinding of granulated blast furnace slag and a sulfate hardening pathogen - gypsum or anhydride with a small addition of an alkaline activator: lime, Portland cement or calcined dolomite. The most widespread sulfate-slag group was gypsum-slag cement, containing 75 ... 85% slag, 10 ... 15% dib gypsum or anhydride, up to 2% calcium oxide or 5% Portland cement clinker. High activation is ensured by using anhydrite annealed at a temperature of about 700º C and high-alumina basic slags. The activity of sulfate-slag cement significantly depends on the fineness of grinding. High specific surface area (4000 ... 5000 cm² / g) of binder is achieved by wet grinding. With a sufficiently high fineness of grinding in a rational composition, the strength of sulfate-slag cement is not inferior to the strength of Portland cement. Like other slag binders, sulfate-slag cement has a low heat of hydration - by 7 days, which allows it to be used in the construction of massive hydraulic structures. This is also facilitated by its high resistance to the effects of soft sulfate waters. The chemical resistance of sulphate-slag cement is higher than slag Portland cement, which makes its use especially suitable in various aggressive conditions.

Lime-slag and lime-ash cements are hydraulic binders obtained by co-grinding granulated blast furnace slag or fly ash of thermal power plants and lime. They are used for the preparation of mortars of grades no more than M 200. To regulate the setting time and improve other properties of these binders, up to 5% of gypsum stone is introduced in the manufacture of them. The lime content is 10% ... 30%.

Lime-slag and ash cements are inferior in strength to sulphate-slag cements. Their grades are 50, 100, 150 and 200. The beginning of setting must occur no earlier than 25 minutes, and the end no later than 24 hours after the beginning of mixing. With a decrease in temperature, especially after 10 ° C, the increase in strength slows down sharply and, conversely, an increase in temperature with sufficient humidity contributes to intensive hardening. Hardening in air is possible only after sufficient prolonged hardening (15 ... 30 days) in humid conditions. These cements are characterized by low frost resistance, high resistance in aggressive waters and low exotherm.

Slag-alkali binders consist of finely ground granulated slag (specific surface area ≥3000 cm² / g) and an alkaline component - alkali metal compounds of sodium or potassium.

To obtain a slag-alkali binder, granular slags with different mineralogical composition are acceptable. The decisive condition for their activity is the content of the vitreous phase, capable of interacting with alkalis.

The properties of the slag alkali binder depend on the type, mineralogical composition of the slag, the fineness of its grinding, the type and concentration of its solution of the alkaline component. With a specific slag surface of 3000 ... 3500 cm² / g, the amount of water for the formation of a test of normal density is 20 ... 30% of the binder mass. The strength of the slag alkali binder when testing samples from the test of normal density is 30 ... 150 MPa. They are characterized by an intensive increase in strength both during the first month and in the subsequent hardening periods. So, if the strength of Portland cement after 3 months. hardening under optimal conditions exceeds the grade by about 1.2 times, then the slag alkali binder by 1.5 times. During heat-moisture treatment, the hardening process is also accelerated more intensively than during hardening of Portland cement. Under normal steaming conditions adopted in precast concrete technology, for 28 days. 90 ... 120% of brand strength is achieved.

The alkaline components that make up the binder play the role of an anti-frost additive, therefore, cinder-alkaline binders harden quite intensively at low temperatures.

b) Slag ash aggregates

Slag and ash waste represent a rich raw material base for the production of both heavy and light porous concrete aggregates. The main types of aggregates based on metallurgical slag are slag crushed stone and slag pumice.

Porous aggregates are made from fuel slags and ashes, including agloporite, fly ash, gravel, and clay clay clay.

The effective types of heavy concrete aggregates, not inferior in physical and mechanical properties to the crushing product of dense natural stone materials, include cast slag crushed stone. In the production of this material, molten fire-liquid slag from slag ladles is poured in layers of 200 ... 500 mm thick onto special foundry pads or into tarp-shaped trench pits. When kept for 2 ... 3 hours in the open air, the temperature of the melt in the layer decreases to 800 ° C, and the slag crystallizes. Then it is cooled by water, which leads to the development of numerous cracks in the slag layer. Slag masses at foundries or in trenches are developed by excavators with subsequent crushing.

Cast slag crushed stone is characterized by high frost and heat resistance, as well as abrasion resistance. Its cost is 3 ... 4 times lower than gravel from natural stone.

Slag pumice (slows down) is one of the most effective types of artificial porous aggregates. It is obtained by the porization of slag melts as a result of their rapid cooling with water, air or steam, as well as the influence of mineral blowing agents. Of the technological methods for producing slag pumice, the most commonly used pool, jet and hydro-screen methods.

Fuel slag and ashes are the best raw materials for the production of artificial porous aggregate - agloporite. This is due, firstly, to the ability of ash and slag raw materials, like clayey rocks and other aluminosilicate materials, to sinter on the gratings of sintering machines, and secondly, to contain in it the remaining fuel sufficient for the sintering process. Using conventional technology, agloporite is obtained in the form of crushed stone from sand. From the ashes of thermal power plants it is possible to obtain agloporite gravel, which has high technical and economic indicators.

The main feature of agloporite gravel technology is that, as a result of agglomeration of raw materials, not sintered cake is formed, but burnt granules. The essence of the technology for the production of agloporite gravel is to obtain raw ash granules with a particle size of 10 ... 20 mm, laying them on the grates of a ribbon sintering machine with a layer 200 ... 300 mm thick and heat treatment.

Compared to conventional sinter production, sinter production is characterized by a 20 ... 30% reduction in process fuel consumption, lower air pressure in vacuum chambers and an increase in specific productivity by 1.5 ... 3 times. Agloporite gravel has a dense surface shell and therefore, with almost equal bulk mass with crushed stone, it differs from it by higher strength and less water absorption. It is estimated that replacing 1 million m³ of imported natural gravel with agro-port gravel from TPP ash only by reducing transportation costs for transportation over a distance of 500 ... 1000 km will save 2 million rubles. The use of agloporite based on ash and slag from TPPs allows to obtain lightweight concrete of grades 50 ... 4000 with a bulk density of 900 to 1800 kg / m³ with a cement flow rate of 200 to 400 kg / m³.

Ash gravel is obtained by granulation of the prepared ash and slag mixture or fly ash of thermal power plants, followed by sintering and swelling in a rotary kiln at a temperature of 1150 ... 1250 ° C. Light ash with the same values \u200b\u200bas with agloporite gravel are obtained on ash gravel. In the production of ash gravel, only expanding ashes of thermal power plants with a fuel residue content of not more than 10% are effective.

Alumina expanded clay is a product of swelling and sintering in a rotary kiln of granules formed from a mixture of clay and ash and slag waste from thermal power plants. Ash can make up from 30 to 80% of the total mass of raw materials. The introduction of a clay component improves the molding properties of the mixture, contributes to the burning out of coal residues in the ash, which allows the use of ash with a high content of unburned fuel.

The bulk density of alumina expanded clay is 400..6000 kg / m³, and the compressive strength in a steel cylinder is 3.4 ... 5 MPa. The main advantages of producing clayd claydite in comparison with agloporite and ash gravel are the ability to use TPP ash from waste dumps without the use of drying and grinding aggregates and an easier way to form granules.

c) Fused and artificial stone materials based on slag and ash

The main areas of processing metallurgical and fuel slags, as well as ashes, along with the production of binders, aggregates and concrete based on them, include the production of slag wool, cast materials and slag sinter, fly ash ceramic and silicate brick.

Slag wool is a type of mineral wool, which occupies a leading position among heat-insulating materials, both in terms of output and construction and technical properties. In the production of mineral wool, blast furnace slags are most used. The use of slag instead of natural raw materials saves up to 150 UAH. for 1 ton. To obtain mineral wool, along with blast furnace, cupola, open-hearth slag and non-ferrous metallurgy slag are also used.

The required ratio of acid and basic oxides in the mixture is ensured by the use of acidic slag. In addition, acidic slag is more resistant to degradation, which is unacceptable in mineral wool. An increase in silica content extends the temperature range of viscosity, i.e. temperature difference within which fiber formation is possible. The acidity modulus of the slag is adjusted by introducing acidic or basic additives into the charge.

A variety of products are cast from the melt of metallurgical and fuel slags: stones for paving roads and floors of industrial buildings, tubing, curbs, anticorrosion tiles, pipes. The production of slag casting began simultaneously with the introduction of a blast furnace process into metallurgy. Cast products from slag melt are economically more profitable than stone casting, approaching it in terms of mechanical properties. The bulk density of dense cast products from slag reaches 3000 kg / m³, the compressive strength is 500 MPa.

Slag-metals are a type of glass-crystalline materials obtained by directional crystallization of glasses. Unlike other sitalls, the raw materials for them are slag from ferrous and non-ferrous metallurgy, as well as ash from burning coal. Slag coals were developed for the first time in the USSR. They are widely used in construction as structural and finishing materials with high strength. The production of slag metal consists in the cooking of slag glasses, the formation of products from them and their subsequent crystallization. The mixture for glass production consists of slag, sand, alkali-containing and other additives. The most effective use of fire-liquid metallurgical slag, which saves up to 30 ... 40% of all the heat spent on cooking.

Slag materials are increasingly being used in construction. Plinth slag sheets are faced with socles and facades of buildings, interior walls and partitions are trimmed, fencing of balconies and roofs is made of them. Slag-glass is an effective material for steps, window sills and other structural elements of buildings. High wear resistance and chemical resistance allow the successful use of slag metal for the protection of building structures and equipment in the chemical, mining and other industries.

Ash and slag waste from thermal power plants can serve as thin fuel-containing additives in the production of ceramic products based on clay rocks, as well as the main raw material for the manufacture of ash ceramics. The most widely used fuel ashes and slags as additives in the production of wall ceramic products. For the manufacture of solid and hollow bricks and ceramic stones, it is recommended first of all to use fusible ashes with a softening temperature of up to 1200 ° C. Ashes and slags containing up to 10% of fuel are used as exhausting agents, and 10% or more - as fuel-containing additives. In the latter case, the introduction of technological fuel into the charge can be substantially reduced or eliminated.

A number of technological methods have been developed for the production of ash ceramics, where the ash and slag waste of thermal power plants is no longer an additional material, but the main raw material component. Thus, with the usual equipment of brick factories, ash brick can be made from pulp, including ash, slag and sodium liquid glass in an amount of 3% by volume. The latter serves as a plasticizer, providing products with minimal humidity, which eliminates the need for drying raw.

Ash ceramics is produced in the form of pressed articles from a mass including 60 ... 80% fly ash, 10 ... 20% clay and other additives. Products come to drying and firing. Ash ceramics can serve not only as a wall material with stable strength and high frost resistance. It is characterized by high acid resistance and low friability, which makes it possible to produce paving and road slabs and products with high durability from it.

In the production of silicate brick, ash TPP is used as a component of a binder or aggregate. In the first case, its consumption reaches 500 kg., In the second - 1.5 ... 3.5 tons per 1 thousand units. a brick. With the introduction of coal ash, the consumption of lime is reduced by 10 ... 50%, and shale ashes with a CaO + MgO content of up to 40 ... 50% can completely replace lime in the silicate mass. Ash in a lime-ash binder is not only an active silica additive, but also contributes to the plasticization of the mixture and to increase the raw strength by 1.3 ... 1.5 times, which is especially important for ensuring the normal operation of automatic stackers.

d) Ashes and slags in road building and insulating materials

A large-capacity consumer of fuel ashes and slags is road construction, where ashes and ash and slag mixtures are used to lay underlays and lower layers of the foundations, partially replace binders when stabilizing soils with cement and lime, as mineral powder in asphalt concrete and mortars, as additives in road cement concrete.

Ashes obtained by burning coal and oil shale are used as fillers for roofing and waterproofing mastics. Ash and slag mixtures in road construction are used unreinforced and fortified. Unreinforced ash and slag mixtures are used mainly as a material for the device of underlying and lower layers of the bases of roads of regional and local significance. With a content of not more than 16% dusty ash, they are used to improve soil coatings subjected to surface treatment with bitumen or tar emulsion. Structural layers of roads can be made of ash and slag mixtures with an ash content of not more than 25 ... 30%. In gravel-crushed stone substrates, it is advisable to use an ash-slag mixture with a dust-like ash content of up to 50% as a sealing additive.The content of unburned coal in the fuel waste of TPPs used for road construction should not exceed 10%.

As well as natural stone materials of relatively high strength, ash and slag waste from TPPs are used for the manufacture of bitumen-mineral mixtures used to create structural layers of roads of 3-5 categories. From fuel slag treated with bitumen or tar (up to 2% by weight), black gravel is obtained. Mixing ash heated to 170 ... 200 ° C with a 0.3 ... 2% solution of bitumen in green oil, a hydrophobic powder with a bulk density of 450 ... 6000 kg / m³ is obtained. A hydrophobic powder can simultaneously serve as a hydro- and heat-insulating material. The use of evils as a filler of mastics is common.

e) Materials based on sludge from metallurgical industries

For the production of building materials, nepheline, bauxite, sulfate, white and multi-calcium sludge are of industrial importance. The volume of nepheline sludge alone, suitable for use, is annually more than 7 million tons.

The main area of \u200b\u200bapplication of slurry waste from the metallurgical industry is the manufacture of clinker-free binders, materials based on them, the production of Portland cement and mixed cements. Especially widely used in industry is nepheline (belitic) sludge obtained from the extraction of alumina from nepheline rocks.

Under the leadership of P.I. Bazhenov developed a technology for the manufacture of nepheline cement and materials based on it. Nepheline cement is a product of joint grinding or thorough mixing of pre-ground nepheline sludge (80 ... 85%), lime or another activator, such as Portland cement (15 ... 20%) and gypsum (4 ... 7%). The beginning of setting of nepheline cement should occur no earlier than 45 minutes, the end - no later than 6 hours. after its mixing, His brands 100, 150, 200 and 250.

Nepheline cement is effective for masonry and plaster mortars, as well as for normal and especially autoclaved concrete. Due to plasticity and setting time, solutions on nepheline cement are close to gypsum-gypsum solutions. In normal hardening concrete, nepheline cement provides grades of 100 ... 200, in autoclaved ones - grades of 300 ... 500 at a flow rate of 250 ... 300 kg / m³. Concrete features on nepheline cement are low exometry, which is important to consider when building massive hydraulic structures, high adhesion to steel reinforcement after autoclaving, and increased resistance in mineralized waters.

The binders similar in composition to nepheline cement are binders based on bauxite, sulfate and other sludge from metallurgical industries. If a significant part of these minerals is hydrated, for the binding properties of the sludge to be manifested, it is necessary to dry them in the range of 300 ... 700 ° C. To activate these binders, it is advisable to add lime and gypsum.

Slurry binders are classified as local materials. It is most rational to use them for the manufacture of autoclaved hardening products. However, they can also be used in mortars, during finishing works, in the manufacture of materials with organic aggregates, for example fiberboard. The chemical composition of a number of metallurgical sludges allows them to be used as the main raw material component of Portland cement clinker, as well as an active additive in the production of Portland cement and mixed cements.

f) The use of burnt rocks, coal processing waste, mining and concentration of ores

The bulk of the burnt rocks is a product of firing of waste rocks associated with coal deposits. Varieties of burned rocks are clay slabs - clay and clay-sand rocks, burnt in the bowels of the earth during underground fires in coal seams, and dump, burned out mine rocks.

The possibilities of using burnt rocks and coal processing waste in the production of building materials are very diverse. Burned rocks, as well as other calcined clay materials, are active in relation to lime and are used as hydraulic additives in cementitious lime-pozzolanic type, Portland cement, pozzolanic Portland cement and autoclave materials. High adsorption activity and adhesion to organic binders allow their use in asphalt and polymer compositions. Naturally, burnt rocks burnt in the bowels of the earth or in the heaps of coal mines - mudstones, siltstones and sandstones - have a ceramic nature and can be used in the manufacture of heat-resistant concrete and porous aggregates. Some burned rocks are light non-metallic materials, which determines their use as aggregates for light mortars and concrete.

Coal preparation waste is a valuable type of mineralogical raw material, mainly used in the production of wall ceramic materials and porous aggregates. In terms of chemical composition, coal processing waste is close to traditional clay raw materials. Sulfur contained in sulfate and sulfide compounds acts as a harmful impurity in them. Their calorific value varies widely - from 3360 to 12600 kJkg or more.

in the production of wall ceramic products, coal wastes are used as an exhaust or burnable fuel-containing additive. Before introducing into the ceramic mixture lump waste is crushed. Pre-crushing is not required for sludge with a particle size of less than 1mm. Sludge is pre-dried to a moisture content of 5 ... 6%. The addition of waste upon receipt of the brick in a plastic way should be 10 ... 30%. The introduction of the optimal amount of fuel containing additives as a result of more uniform firing significantly improves the strength characteristics of products (up to 30 ... 40%), saves fuel (up to 30%), eliminates the need to introduce coal into the charge, and increases the productivity of furnaces.

It is possible to use coal-sludge of relatively high calorific value (18900 ... 21000 kJ / kg) as a process fuel. It does not require additional crushing, it is well distributed over the charge when filling through the fuel holes, which contributes to uniform firing of products, and most importantly much cheaper than coal.

Of some varieties of coal enrichment waste, it is possible to produce not only agloporite, but also expanded clay. A valuable source of non-metallic materials are incidentally mined rocks of mining industries. The main direction of disposal of this group of waste is the production of, first of all, aggregates of concrete and mortars, road-building materials, rubble stone.

Crushed stone is obtained from associated rocks during the extraction of iron and other ores. High-quality raw materials for the production of crushed stone are barren ferruginous quartzites: hornfelses, quartzite and crystalline schists. Crushed stone from associated rocks during the extraction of iron ore is obtained at crushing and screening plants, as well as dry magnetic separation.

3. Experience in the use of waste from chemical-technological production and wood processing

a) The use of slags electrothermal production of phosphorus

An important source of building materials is also agricultural waste of plant origin. The annual output, for example, of waste from cotton stalks is about 5 million tons per year, and flax campfire more than 1 million tons.

Wood waste is generated at all stages of its harvesting and processing. These include branches, twigs, peaks, pegs, peaks, sawdust, stumps, roots, bark and brushwood, totaling about 21% of the total mass of wood. When processing wood into lumber, the output reaches 65%, the rest forms waste in the form of croaker (14%), sawdust (12%), cuttings and trifles (9%). In the manufacture of building parts, furniture and other products from lumber, waste arises in the form of shavings, sawdust and individual pieces of wood - cuts that make up up to 40% of the mass of processed lumber.

Most important for the production of building materials and products are sawdust, shavings and lump waste. The latter are used both directly for the manufacture of glued building products, and processing for technological chips, and then shavings, crushed, pulp. A technology has been developed for the production of building materials from bark and odubina - waste from the production of tannin extracts.

Phosphorus slag is a by-product of the production of phosphorus by the thermal method in electric furnaces. At a temperature of 1300 ... 1500 ° C, calcium phosphate interacts with carbon coke and silica, resulting in the formation of phosphorus and slag melt. Slag is drained from the furnaces in a fiery-liquid state and granulated wet. There are 10 ... 12 tons of slag per 1 ton of phosphorus. Large chemical plants receive up to two million tons of slag per year. The chemical composition of phosphorus slag is close to that of blast furnace.

From phosphoric-slag melts it is possible to obtain slag pumice, cotton wool and cast products. Slag pumice is obtained by conventional technology without changing the composition of phosphorus slag. It has a bulk density of 600 ... 800 kg / m³ and a glassy finely porous structure. Phosphorus slag wool is characterized by long thin fibers and bulk density of 80 ... 200 kg / m³. Phosphorus-slag melts can be processed into cast crushed stone using trench technology used at metallurgical enterprises.

b) Materials based on gypsum-containing and ferrous waste

The demand of the building materials industry in gypsum stone currently exceeds 40 million tons. At the same time, the need for gypsum raw materials can be mainly satisfied due to the gypsum-containing wastes of the chemical, food, and wood-chemical industries. In 1980, in our country, the yield of waste and by-products containing calcium sulfates reached approximately 20 million tons per year, including phosphogypsum - 15.6 million tons.

Phosphogypsum is a waste of the sulfuric acid treatment of apatites or phosphorites into phosphoric acid or concentrated phosphoric fertilizers. It contains 92 ... 95% two-water gypsum with a mechanical impurity of 1 ... 1.5% phosphorus pentoxide and some other impurities. Phosphogypsum has the form of sludge with a moisture content of 20 ... 30% with a high content of soluble impurities. The solid phase of the sludge is finely divided and more than 50% consists of particles less than 10 microns in size. The cost of transportation and storage of phosphogypsum in dumps is up to 30% of the total cost of structures and operation of the main production.

In the production of phosphoric acid by the hemihydrate extraction method, the waste is calcium sulfate phospho hemihydrate, containing 92 ... 95%, the main component of high-strength gypsum. However, the presence on the crystal surface of hemihydrate passivating films significantly inhibits the manifestation of the astringent properties of this product without special technological processing.

In conventional technology, phosphogypsum-based gypsum binders are of low quality, which is explained by the high water demand of phosphogypsum, due to the high porosity of the hemihydrate as a result of the presence of large crystals in the feedstock. If the water demand of ordinary building gypsum is 50 ... 70%, then to obtain a test of normal density from a phosphogypsum binder without additional processing, water is required 120 ... 130%. Negatively affect the construction properties of phosphogypsum and its impurities. This effect is somewhat reduced with phosphogypsum domination and product formation by vibro-laying. In this case, the quality of the phosphogypsum binder increases, although it remains lower than that of building gypsum from natural raw materials.

A composite binder of increased water resistance was obtained at the Moscow Institute of Information Technology based on phosphogypsum, containing 70 ... 90% α-hemihydrate, 5 ... 20% Portland cement and 3 ... 10% pozzolanic additives. With a specific surface of 3000 ... 4500 cm² / g, the water demand of the binder is 35 ... 45%, setting begins after 20 ... 30 minutes, ends after 30 ... 60 minutes, the compressive strength is 30 ... 35 MPa, the softening coefficient is 0.6 ... 0 , 7. waterproof binder is obtained by hydrothermal autoclaving of a mixture of phosphogypsum, Portland cement and additives containing active silica.

In the cement industry, Phosphogypsum is used as a mineralizer for clinker roasting and, instead of natural gypsum, as an additive to regulate cement setting. The addition of 3 ... 4% to the sludge allows you to increase the clinker saturation coefficient from 0.89 ... 0.9 to 0.94 ... 0.96 without reducing the productivity of the furnaces, to increase the lining resistance in the sintering zone due to the uniform formation of a stable coating and to obtain an easily milled clinker. The suitability of phosphogypsum for replacing gypsum when grinding cement clinker has been established.

Widespread use of phosphogypsum as an additive in cement production is possible only when it is dried and granulated. The moisture content of granular phosphogypsum should not exceed 10 ... 12%. The essence of the basic scheme for granulating phosphogypsum is to dehydrate part of the initial phosphogypsum sludge at a temperature of 220 ... 250 ° C to the state of soluble anhydride, followed by mixing it with the rest of phosphogypsum. When phosphoanhydride is mixed with phosphogypsum in a rotating drum, the dehydrated product is hydrated due to the free moisture of the starting material, and as a result, solid granules of two-water phosphogypsum are formed. Another method of granulating phosphogypsum is also possible - with a strengthening additive of pyrite cinder.

In addition to the production of binders and products based on them, other ways of recycling gypsum-containing waste are known. The experiments showed that the addition of up to 5% phosphogypsum to the mixture during brick production intensifies the drying process and helps to improve the quality of products. This is explained by the improvement of the ceramic-technological properties of clay raw materials due to the presence of the main component of phosphogypsum - two-water calcium sulfate.

Of the iron waste, pyrite cinders are most widely used. In particular, in the production of Portland cement clinker, they are used as a corrective additive. However, cinders consumed in the cement industry make up only a small part of their total output at sulfuric acid enterprises that consume pyrites as the main feedstock.

A technology has been developed for the manufacture of high-iron cements. Chalk (60%) and pyrite cinder (40%) are the initial components for the production of such cements. The raw mix is \u200b\u200bfired at a temperature of 1220 ... 1250º C. High-iron cements are characterized by normal setting time when up to 3% gypsum is introduced into the raw mix. Their compressive strength under conditions of water and air-wet hardening for 28 days. corresponds to brands 150 and 200, and when steaming in autoclave processing increases by 2 ... 2.5 times. High iron cements are non-shrink.

Pyrite cinder in the production of artificial concrete aggregates can serve as an additive, as well as the main raw material. The addition of pyrite cinder in the amount of 2 ... 4% of the total mass is introduced to increase the gas-generating ability of clays when obtaining expanded clay. This contributes to the decay in the cinders at 700 ... 800º C of pyrite residues with the formation of sulfur dioxide and the reduction of iron oxides under the influence of organic impurities present in clay raw materials, with the release of gases. Ferrous compounds, especially in acidic form, act as fluxes, causing the melt to thin and reduce the temperature range of its viscosity.

Iron-containing additives are used in the production of wall ceramic materials to reduce the firing temperature, improve quality and improve color characteristics. Positive results are obtained by preliminary calcination of the cinders for the decomposition of impurities of sulfides and sulfates, which form gaseous products during firing, the presence of which reduces the mechanical strength of the products. The introduction of 5 ... 10% cinders into the charge is effective, especially in raw materials with a low amount of smoothers and insufficient caking.

In the production of facade tiles by semi-dry and slinker methods, calcined cinder can be added to the mixture in an amount of 5 to 50% by weight. The use of cinders allows the production of colored ceramic facade tiles without additional introduction of fireclay into the clay. In this case, the firing temperature of tiles from refractory and refractory clays is reduced by 50 ... 100 ° C.

c) Materials from the waste of wood chemistry and wood processing

For the production of building materials, the most valuable raw materials from chemical industry wastes are slags of the electrothermal production of phosphorus, gypsum-containing and calcareous wastes.

Waste from winter-technological production include worn-out rubber and secondary polymer raw materials, as well as a number of by-products of building materials enterprises: cement dust, sludges in water treatment apparatus of asbestos-cement enterprises, glass and ceramic fights. Waste accounts for up to 50% of the total mass of processed wood, most of which is currently burned or dumped.

Building materials enterprises located near hydrolysis plants can successfully utilize lignin, one of the most voluminous waste from wood chemistry. The experience of a number of brick factories allows us to consider lignin an effective burn-out additive. It mixes well with other components of the mixture, does not impair its forming properties and does not complicate the cutting of timber. The greatest effect of its use takes place with a relatively low career clay moisture. Pressed into raw lignin during drying does not burn. The combustible part of lignin completely disappears at a temperature of 350 ... 400º C, its ash content is 4 ... 7%. To ensure the conditional mechanical strength of ordinary clay bricks, lignin should be introduced into the forming charge in an amount of up to 20 ... 25% of its volume.

In the production of cement, lignin can be used as a plasticizer for raw sludge and an intensifier for grinding the raw mix and cement. The dosage of lignin in this case is 0.2 ... 0.3%. The liquefying effect of hydrolytic lignin is explained by the presence of phenolic substances in it, which well reduce the viscosity of limestone-clay suspensions. The effect of lignin during grinding consists mainly in reducing the adhesion of small fractions of the material and their adhesion to grinding media.

Wood waste without preliminary processing (sawdust, shavings) or after grinding (wood chips, crushed wood, wood wool) can serve as aggregates in building materials based on mineral and organic binders, these materials are characterized by low bulk density and thermal conductivity, as well as good processability. Impregnation of wood aggregates with mineralizers and subsequent mixing with mineral binders ensures biostability and low combustibility of materials based on them. Common disadvantages of materials on wood aggregates are high water absorption and relatively low water resistance. By designation, these materials are divided into heat-insulating and structurally-heat-insulating.

The main representatives of the group of materials on wood aggregates and mineral binders are arbolite, fiberboard and sawdust concrete.

Arbolit - lightweight concrete on aggregates of plant origin, pre-treated with a solution of mineralizer. It is used in industrial, civil and agricultural construction in the form of panels and blocks for the construction of walls and partitions, floor slabs and building coatings, heat-insulating and sound-insulating plates. The cost of buildings made of wood concrete is 20 ... 30% lower than that of brick. Arbolitic structures can be operated at a relative humidity of indoor air of not more than 75%. With high humidity, a vapor barrier layer is required.

Fibrolite, unlike wood concrete, as a filler and at the same time a reinforcing component, includes wood wool - shavings from 200 to 500 mm long., 4 ... 7 mm wide. and a thickness of 0.25 ... 0.5 mm. Wood wool is obtained from non-wood coniferous, rarely hardwood. The fiberboard is characterized by high sound absorption, easy machinability, nails, good adhesion to the plaster layer and concrete. The technology for the production of fiberboard includes the preparation of wood wool, processing it with a mineralizer, mixing with cement, pressing plates and their heat treatment.

Sawdust concrete is a material based on mineral binders and wood sawdust. These include xylolite, xylobeton and some other materials close to them in composition and technology.

Xylolite is an artificial building material obtained by hardening a mixture of a magnesian binder and sawdust mixed with a solution of magnesium chloride or sulfate. Xylolite is mainly used for monolithic or prefabricated flooring. The advantages of xylolithic floors are a relatively small coefficient of heat absorption, hygiene, sufficient hardness, low abrasion, and the possibility of a variety of color.

Xyl concrete is a type of lightweight concrete, filler which is sawdust, and cement and lime and gypsum are the binding agents, xyl concrete with a bulk density of 300 ... 700 kg / m³ and compressive strength of 0.4 ... 3 MPa is used as heat insulation, and with a bulk mass of 700 ... 1200 kg / m³ and compressive strength up to 10 MPA - as a structural and heat-insulating material.

Glued wood is one of the most effective building materials. It can be laminated or obtained from veneer (plywood, wood-laminated plastics); massive of lumpy waste of sawmilling and woodworking (panels, sheets, boards, boards) and combined (carpentry boards). Advantages of glued wood - low bulk density, water resistance, the ability to obtain complex materials, large structural elements from small-sized material. In glued structures, the effect of anisotropy of wood and its defects is weakened, they are characterized by increased clay resistance and low flammability, are not subject to shrinkage and warping. Glued wooden structures in terms of time and labor for the construction of buildings, resistance to the construction of aggressive air often often compete with steel and reinforced concrete structures. Their use is effective in the construction of agricultural and industrial enterprises, exhibition and trade pavilions, sports complexes, buildings and constructions of collapsible type.

Chipboard is a material obtained by hot pressing of crushed wood mixed with binders - synthetic polymers. The advantages of this material are uniform physical and mechanical properties in various directions, relatively small linear changes with variable humidity, the possibility of high mechanization and automation of production.

Building materials based on some waste wood can be made without the use of special binders. Particles of wood in such materials are bonded as a result of rapprochement and interweaving of fibers, their cohesive ability and physicochemical bonds that occur during processing of the press mass at high pressure and temperature.

Without the use of special binders, wood-fiber boards are obtained.

Fiberboard - a material formed from pulp with subsequent heat treatment. About 90% of all fiber boards are made from wood. The raw materials are non-business wood and waste from sawmill and woodworking industries. Plates can be obtained from the fibers of bast plants and from other fibrous raw materials with sufficient strength and flexibility.

The group of wood plastics includes: Wood-laminated plastics - material from veneer sheets impregnated with a synthetic polymer of the rezol type and glued as a result of heat treatment by pressure, ligno-carbohydrate and piezothermoplastics made from wood sawdust by high-temperature processing of the press mass without introducing special binders. The technology of ligno-carbohydrate plastics consists of preparing, drying and dosing wood particles, molding a carpet, cold pressing it, hot pressing and cooling without relieving pressure. The scope of ligno-carbohydrate plastics is the same as fibreboard and chipboard.

Piezothermoplastics can be made of sawdust in two ways - without preliminary processing and with hydrothermal processing of the feedstock. According to the second method, conditioned sawdust is autoclaved with steam at a temperature of 170 ... 180º C and a pressure of 0.8 ... 1 MPa for 2 hours. The hydrolyzed press mass is partially dried and subsequently subjected to cold and hot pressing at a certain humidity.

From piezothermoplastics produce floor tiles 12 mm thick. Sawdust or shredded coniferous and deciduous wood, flaxseed or hemp bonfire, reeds, hydrolytic lignin, and odubin can serve as the feedstock.

d) Disposal of own waste in the production of building materials

The experience of the enterprises of the Crimean Autonomous Republic developing limestone-shell rock to obtain wall piece stone shows the efficiency of manufacturing shell-concrete blocks from stone sawing waste. Blocks are formed in horizontal metal molds with folding sides. The bottom of the mold is covered with a shell rock solution 12..15 mm thick to create an internal textured layer. The form is filled with coarse or fine-grained shell rock concrete. The texture of the outer surface of the blocks can be created with a special solution. Shell-concrete blocks are used for laying foundations and walls in the construction of industrial and residential buildings.

A significant amount of dust is generated in the production of cement as a result of the processing of finely dispersed mineral materials. The total amount of dust collected at cement plants can be up to 30% of the total output. Up to 80% of the total amount of dust is emitted with clinker kiln gases. The dust carried out from the furnaces is a polydisperse powder, containing 40 ... 70 with the wet production method, and up to 80% of fractions less than 20 microns in size with the dry method of production. Mineralogical studies have established that dust contains up to 20% of clinker minerals, 2 ... 14% of free calcium oxide and from 1 to 8% of alkalis. The bulk of the dust consists of a mixture of calcined clay and undecomposed limestone. The composition of the dust substantially depends on the type of furnaces, the type and properties of the raw materials used, and the capture method.

The main direction of dust utilization in cement plants is its use in the cement production process itself. Dust from the dust collecting chambers is returned to the rotary kiln together with the sludge. The main amount of free calcium oxide, alkali and sulfuric anhydride. The addition of 5 ... 15% of such dust to raw sludge causes its coagulation and decrease in fluidity. With an increased content of alkaline oxides in the dust, clinker quality also decreases.

Asbestos-cement waste contains a large amount of hydrated cement minerals and asbestos. When fired as a result of dehydration of the hydrated components of cement and asbestos, they acquire astringent properties. The optimum firing temperature is in the range of 600 ... 700º C. In this temperature range, dehydration of hydrosilicates is completed, asbestos decomposes and a number of minerals capable of hydraulic hardening are formed. Binders with pronounced activity can be obtained by mixing heat-treated asbestos-cement waste with metallurgical slag and gypsum. From asbestos-cement waste, tiles and floor tiles are made.

An effective type of binder in compositions of asbestos-cement waste is liquid glass. Cladding plates from a mixture of dried and powdered asbestos-cement waste and liquid glass solution with a density of 1.1 ... 1.15 kg / cm³ are obtained at a specific pressing pressure of 40 ... 50 MPa. In the dry state, these plates have a bulk density of 1380 ... 1410 kg / m³, a flexural strength of 6.5 ... 7 MPa, a compression of 12 ... 16 MPa.

Heat-insulating materials can be made from asbestos-cement waste. Products in the form of plates, segments and shells are obtained from burnt and crushed waste with the addition of lime, sand and blowing agents. Aerated concrete based on binders from asbestos-cement waste has a compressive strength of 1.9 ... 2.4 MPa and a bulk density of 370 ... 420 kg / m³. Waste from the asbestos-cement industry can serve as fillers for warm plasters, asphalt mastics and asphalt concrete, as well as aggregates of concrete with high impact strength.

Glass waste is generated both in the production of glass and in the use of glass products at construction sites and in everyday life. The return of cullet to the main technological process for the production of glass is the main direction of its disposal.

One of the most effective heat-insulating materials, foam glass, is obtained from a glass battle powder with gas-forming agents sintering at 800 ... 900 °. Foam glass plates and blocks have a bulk density of 100 ... 300 kg / m³, thermal conductivity of 0.09 ... 0.1 W and a compressive strength of 0.5 ... 3 MPa.

In a mixture with plastic clays, glass break can serve as the main component of ceramic masses. Products from such masses are made by semi-dry technology, they are distinguished by high mechanical strength. The introduction of glass battle into the ceramic mass reduces the firing temperature and increases the productivity of furnaces. Glass ceramic tiles are produced from a charge comprising 10 to 70% of the breakage of glass crushed in a ball mill. The mass is moistened to 5 ... 7%. The tiles are pressed, dried and fired at 750 ... 1000º С. The water absorption of the tiles is not more than 6%. frost resistance more than 50 cycles.

Broken glass is also used as a decorative material in colored plasters, ground glass waste can be used as a dusting powder for oil paint, abrasive for the manufacture of sandpaper and as a component of glaze.

In ceramic production, waste occurs at various stages of the technological process. Drying waste after necessary grinding serves as an additive to reduce the moisture content of the initial charge. The clay brick fight is used after crushing as crushed stone in general construction works and in the manufacture of concrete. Crushed stone has a bulk density of 800 ... 900 kg / m³, it is possible to produce concrete with a bulk mass of 1800 ... 2000 kg / m³, i.e. 20% lighter than conventional heavy aggregates. The use of crushed stone is effective for the manufacture of coarse-porous concrete blocks with a bulk density of up to 1400 kg / m³. The number of brick battles fell sharply due to containerization and the complex mechanization of loading and unloading bricks.

4. References:

Bozhenov P.I. Complex use of mineral raw materials for the production of building materials. - L.-M.: Stroyizdat, 1963.

Smooth K.V. Slags are not waste, but valuable raw materials. - M.: Stroyizdat, 1966.

Popov L.N. Building materials from industrial waste. - M.: Knowledge, 1978.

Bazhenov Yu.M., Shubenkin P.F., Dvorkin L.I. The use of industrial waste in the production of building materials. - M .: Stroyizdat, 1986.

Dvorkin L.I., Pashkov I.A. Building materials from industrial waste. - K .: Higher school, 1989.

Ministry of Science and Education of Ukraine Kiev National University of Construction and Architecture Department of Building Materials Science Abstract on the topic: “Use of secondary products in the manufacture of building materials

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