RU2530035C1 - Method for producing lightweight ceramic heat-insulating building material - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method for producing lightweight ceramic heat-insulating building material, comprising mixture of pre-treated silica-containing component and alkaline component, homogenization of raw mixture, drying of the granulated raw mixture, grinding of dried granules and firing in metal moulds. At that, the preliminary treatment of silica-containing component is carried out at stone-separating rolls in order to remove strong impurities and activate the silicon dioxide, in the drying apparatus to achieve the humidity of 19-25% and in grinding device in order to achieve the maximum particle size of 1 mm. Diatomite o tripoli and/or flask, containing the active silicon dioxide is used as silica-containing component, mixture of caustic soda and soda ash in the ratio of 0.5-0.8/1 is used as alkali component. Mixing of silica-containing component and alkaline component is carried out in the mixer of periodic action, providing the content of mass fraction in dry raw mixture of caustic soda of 6-14% and soda ash of 6-15%. Homogenization of raw mixture is carried out by treatment in strew press with filtering grid with size of cells of 8-25 mm, and drying of granular raw material mixture is carried out in dryer drum until the humidity of 5-7% is achieved. Grinding of dried granules is performed until the achievement of maximum particle size of 3 mm, and firing of silicate mixture, obtained as a result of grinding, is carried out in metal moulds in oven by raising the temperature up to 650°C with speed of 100-120°C/hour, and up to maximum of 680-800°C - with speed of 15-25°C/hour with subsequent isothermal exposure at maximum temperature during 1-3 hours, cooling from the maximum temperature up to 600°C is carried out with speed of 30-50°C/hour and from 600 to 50°C - with speed of 50-60°C/hour.

EFFECT: reduction of energy costs and improvement of hygienic and sanitary conditions of production.

4 cl, 5 ex, 3 tbl, 1 dwg

Description

The invention relates to the building materials industry, and more particularly to methods for producing expanded ceramic heat-insulating material from widespread and available raw materials containing active silica. Lightweight building material can be used for thermal insulation of structures of buildings and structures, various industrial installations, for the manufacture of both large-sized products, such as blocks, including foundations, plates, panels, etc., as well as small ones, up to bulk expanded clay type .

The prior art method for producing a lightweight ceramic heat-insulating and heat-insulating structural building material, comprising mixing a siliceous component and an alkaline component, homogenizing the raw material mixture, pre-firing the granular raw material mixture, grinding the fired granules and firing the milled powder in metal forms, characterized in that process the silica-containing component on stone extraction rollers to remove tr of crushed inclusions, diatomite or tripoli and / or flask containing active silica are used as a silica-containing component, and a mixture of caustic soda and soda ash in a ratio of 0.5-0.8 / 1 is used as an alkaline component, preliminary firing of the granular raw material mixture is carried out at a temperature of 500-600 ° C in a rotary kiln, see US Pat. RU No. 2442762, class C04B 38/08, published 02/20/2012. The advantages of the method are its technological availability and increased energy efficiency. The disadvantage of this method is the unreasonably complicated and costly process of pre-firing the granular raw mixture and subsequent grinding of the fired granules into powder.

A known method of obtaining a building material, comprising mixing a silica-containing component, an alkaline component and water to obtain a homogeneous silicate mass, which is subjected to temperature treatment before filling the form to a residual moisture content of less than 5 wt.%, Grinding to a particle size of not more than 80-100 microns, after filling the silicate mass of the mold is heated to a temperature of expansion of the silicate mass, cooled and take out the finished product, see US Pat. RU No. 2300506, class C04B 28/24, published June 10, 2007. The building material according to the method is made on the basis of widely available siliceous rocks, and it has improved performance characteristics. The disadvantage of this method is the lack of granulation of the silicate mass. In addition, the silicate mass of this formulation is a viscous mass that adheres to the mixer, and a high moisture content (up to 55.5%) requires high drying costs to a residual moisture content of less than 5 wt.%. Crushing of the silicate mass dried up to 5% moisture and subsequent grinding to a particle size of not more than 80-100 microns is inevitably associated with increased dustiness of the production facilities with alkali-containing particles. Thus, the known method is laboratory and practically impracticable in conditions of real production on the currently existing technological equipment.

A known method of producing a lightweight ceramic heat-insulating and heat-insulating structural building material, comprising mixing a silica-containing component and an alkaline component, homogenizing the raw material mixture, pre-firing the granular raw material mixture, grinding the fired granules and firing the milled powder in metal forms, according to which the silica-containing component is preliminarily processed stone extraction rollers to remove impractical inclusions and a of silica activation, in the drying device to achieve a moisture content of 18-24% and in the grinding device to achieve a maximum particle size of 3 mm, diatomite or tripoli and / or flask containing active silica are used as the silica-containing component, the silica-containing component and the alkaline component are mixed in a batch mixer with ensuring the content of the mass fraction in the dry raw mix of caustic soda 6-12% and soda ash 6-10%, homogenization of the raw mix is carried out by we process in a screw press with a filter grate with a mesh size of 10-25 mm, the grinding of ground powder is carried out in metal forms in the furnace by raising the temperature to 650 ° C at a speed of 100-120 ° C / h, and to a maximum of 680-800 ° C - at a speed of 15-25 ° C / h followed by isothermal exposure at a maximum temperature for 1-3 hours, cooling from a maximum temperature to 600 ° C is carried out at a speed of 30-50 ° C / h and from 600 to 50 ° C with speed of 50-60 ° C / h, see US Pat. RU No. 2473516, class C04B 38/00, No. 2473516, published January 27, 2013. The invention is characterized by the possibility of producing heat-insulating material with increased strength characteristics in finished products using currently existing technological equipment.

The disadvantages of this method are the unreasonably long and energy-intensive process of pre-firing the granular raw mix at a temperature of 550-650 ° C, subsequent re-wetting of the pre-fired granules to a moisture content of 5-7% and grinding the granules into a powder with a maximum particle size of less than 0.1 mm The use of a 46% aqueous solution of caustic soda and an aqueous solution of soda ash as an alkaline component also increases the energy consumption and duration of the preliminary firing process. It should be noted that during the preliminary firing at a temperature of 650 ° C, all physical water is removed from the granules and the main hydroxides that are part of the silicate mass are dehydrated, i.e. the process of expansion due to vaporization is completed. The complete removal of water from the granules during the preliminary firing process is not only energy-intensive, but also useless, since the expanded granules are then milled into powder, i.e. the porous material is again converted into a silicate mass of fine grinding. Grinding granules into a powder with a maximum particle size of less than 0.1 mm is itself energy-intensive, long-term and environmentally stressful. In addition, moistening up to 5-7% of the granules before grinding increases the time of subsequent firing in the molds.

The present invention is aimed at achieving a technical result, which is expressed in reducing the degree of crushing of the granular raw mix due to its partial drying while maintaining the quality of the finished material. Ultimately, the specified technical result can significantly reduce energy consumption during crushing of the granular raw material mixture prior to its heat treatment, as well as improve the unitary-hygienic conditions of production. In the developed method, the main positive properties of the known technical solutions are preserved, the most important of which is the use of widely available siliceous rocks for the production of lightweight ceramic heat-insulating building material.

The specified technical result is achieved by the fact that the method of manufacturing a lightweight ceramic heat-insulating building material involves mixing a pre-processed silica-containing component and an alkaline component, homogenizing the raw material mixture, drying the granular raw material mixture, crushing the dried granules and firing in metal forms. According to the method, the pretreatment of the silica-containing component is carried out on stone extraction rollers to remove impractical inclusions and activation of silica, in a drying device to achieve a moisture content of 19-25% and in a grinding device to achieve a maximum particle size of 1 mm. As a silica-containing component, diatomite or tripoli and / or flask containing active silica are used, and a mixture of caustic soda and soda ash in a ratio of 0.5-0.8 / 1 is used as an alkaline component. The mixture of the silica-containing component and the alkaline component is carried out in a batch mixer to ensure the content of the mass fraction in the dry raw mix of caustic soda 6-14% and soda ash 6-15%. The homogenization of the raw material mixture is carried out by processing in a screw press with a filter grate with a mesh size of 8-25 mm, the granulated raw material mixture is dried in a drying drum until a moisture content of 5-7% is reached, crushing of the dried granules is carried out until a maximum particle size of 3 mm is reached. The firing of the silicate mixture obtained by crushing is carried out in metal forms in the furnace by raising the temperature to 650 ° C at a speed of 100-120 ° C / h, and to a maximum of 680-800 ° C at a speed of 15-25 ° C / h followed by isothermal exposure at a maximum temperature for 1-3 hours, cooling from a maximum temperature to 600 ° C is carried out at a speed of 30-50 ° C / hour and from 600 to 50 ° C at a speed of 50-60 ° C / hour.

The optimal from the point of view of achieving the specified technical result is the mixing of a silica-containing component, and an alkaline component in which caustic soda is introduced in the form of a 46% solution. It is preferable to dry the granular feed mixture at a temperature of 80-250 ° C. It is advisable to crush the dried granules in a rod mixer or ball mill, and firing the silicate mixture in a tunnel or batch furnace.

The technical solution, characterized by the described set of essential features, is new, industrially applicable and has an inventive step.

The developed method is the result of further consistent creative improvement of the technology and production modes of lightweight ceramic heat-insulating building material based on existing technological equipment and raw materials, taking into account increased unitary-hygienic and environmental requirements, the required quality and cost of production.

The author of the developed method is based on the principle of the synergistic effect of the expansion of silicate mass during its roasting. In the process of drying the granular raw mix, physical water is removed from it, but not all. The remaining moisture of 5-7% is sufficient to prevent dusting during crushing, and subsequently during firing it participates in the process of expansion in the form of water vapor. Since the granular raw material mixture during drying and subsequent crushing is not subjected to significant temperature effects, it stores not only physical water, but also all chemically bound water (hydroxides of iron, aluminum, silicon). When firing a silicate mixture, its dehydration occurs, chemically bound water turns into steam, which ensures the formation of pores in the ceramic, its expansion. The most important factor in the expansion of the silicate mixture is the gas formation in it that occurs during firing. Natural raw materials, such as tripoli, diatomite or flask, contain active silica with the ability to release gaseous products during firing in the temperature range 680-800 ° C. And finally, due to the decomposition of soda ash (Na ₂ CO ₃ ) in the presence of caustic soda (NaOH), when calcining the silicate mixture, carbon dioxide (CO ₂ ) is released in it, contributing to swelling. In this case, caustic soda (NaOH) acts as a catalyst for the melting and decomposition of soda ash (Na ₂ CO ₃ ).

In order to ensure a minimum pore size and sufficient amount in the building material, the silicate mass must be crushed to the minimum size of the main fraction. Moreover, the finer the grinding of the silicate mass, the smaller the pores and in larger quantities the material has. It was experimentally established that the synergistic effect of expanding the silicate mass during its firing is so powerful that it provides high-quality building material even when crushing dried granules to a maximum particle size of 3 mm. With such grinding, a good ratio between the energy consumption for grinding and the resulting operational characteristics of the material is ensured.

The experimentally established limit values of the technological parameters of the processing of raw materials, the ratio of the mass fraction of caustic and soda ash in the alkaline component and the raw material mixture, as well as the temperature conditions of firing, are optimal and sufficient to obtain the necessary characteristics of building ceramics, including their density, strength and moisture absorption. Thus, all the features of the method of manufacturing a lightweight ceramic heat-insulating building material, both general and private, are aimed at obtaining a technical result, namely, reducing the degree of crushing of the granular raw material mixture. These essential features of the method are not obviously the following from the prior art even for a highly qualified specialist, indicate the creative nature of the technical solution.

The technical solution is illustrated by a diagram, which presents an approximate schematic flow chart of the production of lightweight ceramic heat-insulating building material with a capacity of up to 100 thousand m ³ / year, indicating the existing technological equipment, implemented as a continuous production line.

In accordance with the presented technological scheme, the production of lightweight ceramic heat-insulating and heat-insulating structural building material is carried out as follows.

The initial silica-containing component, namely, the natural raw material: diatomite or tripoli, or flask, or tripoli mixture with flask containing active silica, is loaded from the warehouse or directly from the quarry into the MA4-003 feeder or feeders IPD21, from where via a conveyor belt enters the preliminary processing, carried out by means of stone-extraction rollers VK-1, to remove intractable inclusions. Pretreatment of the silica-containing component on the stone extraction rollers can significantly intensify active silica in it. Thus prepared silica-containing component is dried in a drying drum or mill-dryer to a residual moisture content of 19-25%, processed in a core mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer by means of a weight batcher. At the same time, an alkaline component consisting of caustic soda is loaded into a batch mixer by means of parallel independent line threads consisting, respectively, of a caustic soda receiving hopper (NaOH) and soda ash receiving hopper (Na ₂ CO ₃ ) equipped with screw conveyors and weighing batchers and soda ash in a ratio of 0.5-0.8 / 1. In this case, the alkali is mainly introduced in the form of granules, and soda in the form of a powder, however, depending on the moisture content of the silica-containing component, the alkali can be introduced in the form of a 46% solution. The ratio of caustic and soda ash in the alkaline component depends on the content of active silica in the initial silica-containing raw material. The mixture of the silica-containing component and the alkaline component is carried out for 3-5 minutes to ensure the content of the mass fraction in the calcined material of caustic soda (NaOH) 6-14% and soda ash (Na ₂ CO ₃ ) 6-15%. The content of caustic soda in the feed mixture is not more than 14% and the moisture content of the feed mixture up to 35% ensures its sufficient flowability and eliminates sticking to the mixer mechanisms.

The resulting finished raw material mixture is discharged from the mixer and, through the UMATP-22 feeder, is sent for homogenization to the SMK-506 screw press granulator, which ensures high productivity and stable particle size distribution in a continuous cycle. Existing screw press equipment is equipped with a filter grate with a mesh size of 8-25 mm. The granular feed mixture obtained in the screw press is sent via a conveyor belt for drying to a drying drum 20 m long. To exclude dusting and improve crushing conditions in a core mixer or ball mill, the granules are dried to a moisture content of 5-7%. The granular raw material mixture is dried in a drying drum at a temperature of 80-250 ° C. The final homogenization and crushing of granules is carried out in a SK-09 rod mixer or in a ball mill until a mixture with a maximum particle size of less than 3 mm is obtained. With a raw material charge moisture of 5-7%, rod mixers and ball mills work stably, realize high productivity of a homogeneous mixture with a maximum particle size of up to 3 mm.

The silicate mixture obtained by crushing, fill the metal molds of products, while the shapes and sizes of products can be very diverse from simple with a size of a few centimeters to complex with a size of several meters. The forms are sent for firing in a tunnel kiln or a batch kiln, where they are heated to a temperature of 680-800 ° C. The temperature rise in the furnace to 650 ° C is carried out at a speed of 100-120 ° C / hour, the temperature rise from 650 ° C to a maximum of 680-800 ° C - at a speed of 15-25 ° C / hour. During the temperature rise in the furnace, the silicate mixture swells. Then, the oven is sequentially isothermally held at a maximum temperature for 1-3 hours, cooling from a maximum temperature of 600 ° C at a speed of 30-50 ° C / h and from 600 to 50 ° C at a speed of 50-60 ° C / hour. Modern furnaces have a certain temperature inertia and accuracy of temperature control, based on which the temperature conditions of firing are determined. After firing, the molds of the products to be fired are taken out of the furnace, cooled to ambient temperature, and transferred to the product forming station by means of an electric transfer trolley, where the finished material is removed from the molds and sent to the finished goods warehouse.

The possibility of implementing a method for the production of lightweight ceramic insulating and heat-insulating structural building material is confirmed by the following examples.

Example 1

Tripoli of the Kaluga deposit of the Kaluga region, the chemical composition of which is presented in Table 1, was taken as a silica-containing component.

Table 1 The chemical composition of the trepel rock of the Kaluga field CO ₂ content Name of definitions (wt.%) SiO ₂ A1 ₂ O ₃ TiO ₂ Fe ₂ O ₃ CaO MgO SO ₃ Na ₂ O K ₂ O Loss on ignition SiO ₂ active Al ₂ O ₃ per calcined substance 5.87 66.60 9.73 0.21 3.30 8.09 0.78 0.16 0.24 0.81 10,2 49.36 10.5

Tripoli with a career humidity of 42% was processed on stone-separating rollers. Thus prepared material containing active silica was dried to a residual moisture content of 19-25%, processed in a rod mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer using a weight batcher. At the same time, an alkaline component consisting of caustic soda (NaOH) and soda ash (Na ₂ CO ₃ ) was charged into a batch mixer. In this case, alkali (NaOH) was introduced in the form of granules, and soda (Na ₂ CO ₃ ) in the form of a powder. The alkali content (NaOH) in the raw mix in terms of calcined products was 14%, and soda (Na ₂ CO ₃ ) was 15%. The moisture content of the raw mix was 30.5%. However, it had sufficient flowability and did not adhere to the mixer mechanisms. The pre-mixed raw material mixture was removed from the mixer and, in order to homogenize it, was processed in a screw press with a filter grate. When processing the mixture in a screw press, the granules exiting the press had good uniformity. The granules were dried to a residual moisture content of 5% and then crushed to a main fraction of less than 3 mm in a ball mill. Shredded particles of silicate mass filled a rectangular metal mold with dimensions of 250 × 120 × 65 mm and placed in a muffle furnace. The silicate mass was heated to 650 ° C for 4 hours, then the temperature in the furnace was raised to 680 ° C for 6 hours and the temperature in the furnace was kept at 680 ° C for 1 hour. Then, the heating element of the furnace was turned off, and the material was allowed to cool naturally in a closed furnace to a temperature of 50 ° C for 10 hours, after which the intumescent sample was removed from the mold.

The cooled sample of the obtained building material with a size of 250 × 120 × 65 mm was removed from the mold and cut into several parts. The structure of the material is uniform, the porosity of the material is uniform, there are no voids and seals. Pore size up to 1 mm. Density 150 kg / m ³ , thermal conductivity coefficient 0,055 W / m ° C, compressive strength 18 kgf / cm ² . The resulting lightweight ceramic building material relates to heat-insulating building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial installations, equipment, refrigerators, pipelines and vehicles, including for the manufacture of both small-sized and large-sized products, such as blocks, plates, panels, etc.

Example 2

The raw material mixture was prepared from the same components as in Example 1. A material containing active silica with a quarry moisture of 40% was processed on stone-separating rollers. Thus prepared material containing active silica was dried to a residual moisture content of 20%, processed in a rod mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer. At the same time, an alkaline component consisting of caustic soda and soda ash was loaded into the mixer. In this case, alkali (NaOH) was introduced in the form of a 46% solution, and soda (Na ₂ CO ₃ ) in the form of a powder. The alkali content (NaOH) in the raw mix in terms of calcined products was 14%, and soda (Na ₂ CO ₃ ) was 15%. The moisture content of the raw mix amounted to 31.5%. However, it had sufficient flowability and did not adhere to the mixer mechanisms. The pre-mixed raw material mixture was removed from the mixer and, in order to homogenize it, was processed in a screw press with a filter grate. When processing the mixture in a screw press, the granules exiting the press had good uniformity. The granules were dried to a residual moisture content of 6% and then crushed to a main fraction of less than 3 mm in a ball mill. Shredded particles of silicate mass filled a rectangular metal mold with dimensions 200 × 200 × 400 mm and placed in a muffle furnace. The silicate mass was heated to 650 ° C for 3 hours, then the temperature in the furnace was raised to 720 ° C for 5 hours and the temperature in the furnace was kept at 720 ° C for 2 hours. Then, the heating element of the furnace was turned off, and the material was allowed to cool naturally in a closed furnace to a temperature of 50 ° C for 10 hours, after which the intumescent sample was removed from the mold.

The cooled sample of the obtained building material 200 × 200 × 400 mm in size was removed from the mold and cut into several parts. The structure of the material is uniform, the porosity of the material is uniform, there are no voids and seals. Pore size up to 1 mm. Density 350 kg / m ³ , thermal conductivity coefficient 0,086 W / m ° C, compressive strength 46 kgf / cm ² . The resulting lightweight ceramic building material relates to heat-insulating structural building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial installations, including for the manufacture of both small-sized and large-sized products, such as blocks, panels, etc.

Example 3

The raw material mixture was prepared from the same components as in Example 1. A material containing active silica with a career moisture content of 39% was treated on a stone roll. Thus prepared material containing active silica was dried to a residual moisture content of 24%, processed in a rod mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer. At the same time, an alkaline component consisting of caustic soda and soda ash was loaded into the mixer. In this case, alkali (NaOH) was introduced in the form of granules, and soda (Na ₂ CO ₃ ) in the form of a powder. The alkali content (NaOH) in the raw mix in terms of calcined products was 14%, and soda (Na ₂ CO ₃ ) was 15%. The moisture content of the raw mix amounted to 29.5%. However, it had sufficient flowability and did not adhere to the mixer mechanisms. The pre-mixed raw material mixture was removed from the mixer and, in order to homogenize it, was processed in a screw press with a filter grate. When processing the mixture in a screw press, the granules exiting the press had good uniformity. The granules were dried to a residual moisture content of 5% and then crushed to a main fraction of less than 3 mm in a ball mill. The crushed particles of silicate mass were filled into a metal mold with dimensions of 1500 × 3000 × 300 mm and placed in an oven. The silicate mass was heated to 650 ° C for 8 hours, then the temperature in the furnace was raised to 740 ° C for 8 hours and the temperature in the furnace was kept at 740 ° C for 3 hours. Then the heating element of the furnace was turned off and the material was allowed to cool naturally in a closed furnace to a temperature of 50 ° C for 12 hours, after which the swollen panel sample was removed from the mold.

A cooled sample of the obtained building material with a size of 1500 × 3000 × 300 mm was removed from the mold and cut into several parts. The structure of the material is uniform, the porosity of the material is uniform, there are no voids and seals. Pore size up to 1 mm. Density 405 kg / m ³ , thermal conductivity coefficient 0.091 W / m ° C, compressive strength 56 kgf / cm ² . The resulting lightweight building material relates to heat-insulating structural building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial installations, including for the manufacture of both small-sized and large-sized products, such as blocks, plates, panels, etc.

Example 4

The diatomite of the Potaninsky deposit, the chemical composition of which is presented in table 2, was taken as a silica-containing component.

table 2 The chemical composition of diatomite Potaninsky deposits CO ₂ content Name of definitions (wt.%) SiO ₂ A1 ₂ O ₃ TiO ₂ Fe ₂ O ₃ CaO MgO SO ₃ Na ₂ O K ₂ O Loss on ignition SiO ₂ active Al ₂ O ₃ per calcined substance 5.87 79.12 9.33 0.38 4.09 0.98 1.01 0.31 0.22 0.36 4.36 28.40 9.75

Diatomite with a moisture content of 43% was treated on a stone extraction roller. Thus prepared material containing active silica was dried to a residual moisture content of 23%, processed in a rod mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer. At the same time, an alkaline component consisting of caustic soda and soda ash was loaded into the mixer. In this case, alkali (NaOH) was introduced in the form of a 46% solution, and soda (Na ₂ CO ₃ ) in the form of a powder. The alkali content (NaOH) in the raw mix in terms of calcined products was 14%, and soda (Na ₂ CO ₃ ) was 15%. The moisture content of the raw mix amounted to 30.5%. However, it had sufficient flowability and did not adhere to the mixer mechanisms. The pre-mixed raw material mixture was removed from the mixer and, in order to homogenize it, was processed in a screw press with a filter grate. When processing the mixture in a screw press, the granules exiting the press had good uniformity. The granules were dried to a residual moisture content of 5% and then crushed to a main fraction of less than 3 mm in a ball mill. The crushed particles of silicate mass were filled in a metal mold with dimensions 200 × 200 × 400 mm and placed in an oven. The silicate mass was heated to 650 ° C for 5 hours, then the temperature in the furnace was raised to 760 ° C for 7 hours and the temperature in the furnace was kept at 760 ° C for 2 hours. Then, the heating element of the furnace was turned off, and the material was allowed to cool naturally in a closed furnace to a temperature of 50 ° C for 10 hours, after which the swollen panel sample was removed from the mold.

The cooled sample of the obtained building material 200 × 200 × 400 mm in size was removed from the mold and cut into several parts. The structure of the material is uniform, the porosity of the material is uniform, there are no voids and seals. Pore size up to 1 mm. Density 465 kg / m ³ , thermal conductivity 0.107 W / m ° C, compressive strength 78 kgf / cm ² . The resulting lightweight building material relates to heat-insulating structural building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial installations, including for the manufacture of both small-sized and large-sized products, such as blocks, plates, panels, etc.

Example 5

As a silica-containing component, we took the trepokochno-reference rock of the Fokinsky deposit, the chemical composition of which is presented in Table 3.

Table 3 The chemical composition of the treplochno-opochnoy breed Fokinskoye deposits CO ₂ content Name of definitions (wt.%) SiO ₂ Al ₂ O ₃ TiO ₂ Fe ₂ O ₃ CaO MgO SO ₃ Na ₂ O K ₂ O Loss on ignition SiO ₂ active Al ₂ O ₃ per calcined substance 1.20 81.58 6.45 0.17 2.00 3.08 0.40 0.14 0.25 1,03 4.40 34.50 5.59

Trepelno-opochny breed with a moisture content of 34% was processed on a stone drum. Thus prepared material containing active silica was dried to a residual moisture content of 18%, processed in a rod mixer to a maximum particle size of 1 mm, and then loaded into a batch mixer. At the same time, an alkaline component consisting of caustic soda and soda ash was loaded into the mixer. In this case, alkali (NaOH) was introduced in the form of granules, and soda (Na ₂ CO ₃ ) in the form of a powder. The alkali content (NaOH) in the raw mix in terms of calcined products was 14%, and soda (Na ₂ CO ₃ ) was 15%. The moisture content of the raw mix amounted to 28.5%. However, it had sufficient flowability and did not adhere to the mixer mechanisms. The pre-mixed raw material mixture was removed from the mixer and, in order to homogenize it, was processed in a screw press with a filter grate. When processing the mixture in a screw press, the granules exiting the press had good uniformity. The granules were dried to a residual moisture content of 5% and then crushed to a main fraction of less than 3 mm in a ball mill. The crushed particles of silicate mass were filled in a metal mold with dimensions 250 × 120 × 88 mm and placed in an oven. The silicate mass was heated to 650 ° C for 4 hours, then the temperature in the furnace was raised to 800 ° C for 8 hours and the temperature in the furnace was kept at 800 ° C for the first hour. Then the heating element of the furnace was turned off and the material was allowed to cool naturally in a closed furnace to a temperature of 50 ° C for 12 hours, after which the swollen panel sample was removed from the mold.

The cooled sample of the obtained building material with a size of 250 × 120 × 88 mm was removed from the mold and cut into several parts. The structure of the material is uniform, the porosity of the material is uniform, there are no voids and seals. Pore size up to 1 mm. Density 635 kg / m ³ , thermal conductivity 0.135 W / m ° C, compressive strength 168 kgf / cm ² . The resulting lightweight building material relates to heat-insulating structural building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial installations, including for the manufacture of both small-sized and large-sized products, such as blocks, including foundation, plates, panels, etc.

The examples of the method described above clearly confirm the versatility of the method and the possibility of its implementation within the boundary values of the mass fraction of components and technological modes. However, the above examples are not exhaustive and are presented only for the purpose of explaining the invention and confirming its industrial applicability. Specialists in this field can improve it and / or implement alternative options within the essence of the present invention, reflected in the description and diagram.

An advantage of the invention is the possibility of production by means of the described method in almost any brick factory from available raw materials of both shaped oversized products and bulk materials with the conditional shape of granules, such as expanded clay. Products manufactured by this method are characterized by high mechanical strength at low cost and good ecology.

Claims (5)

1. A method of manufacturing a lightweight ceramic heat-insulating building material, comprising mixing a pre-treated silica-containing component and an alkaline component, homogenizing the raw mix, drying the granular raw mix, crushing the dried granules and firing in metal molds, while pre-processing the silica-containing component is carried out on stone extraction rollers for removal intractable inclusions and activation of silica in the drying device for achieved I have a moisture content of 19-25% and in the grinding device to achieve a maximum particle size of 1 mm, diatomite or tripoli and / or flask containing active silica are used as the silica-containing component, and a mixture of caustic soda and soda ash in the ratio 0 is used as the alkaline component , 5-0.8 / 1, the mixture of the silica-containing component and the alkaline component is carried out in a batch mixer with a mass fraction of 6-14% caustic soda and calcined 6-15%, homogenization of the raw material mixture is carried out by processing in a screw press with a filter grate with a mesh size of 8-25 mm, drying of the granular raw material mixture is carried out in a drying drum until a moisture content of 5-7% is reached, crushing of the dried granules is carried out to achieve maximum particle size particles of 3 mm, the firing of the silicate mixture obtained by crushing is carried out in metal forms in the furnace by raising the temperature to 650 ° C at a speed of 100-120 ° C / h, and to a maximum of 680-800 ° C at a speed of 15-25 ° C / hour followed by isot By thermal holding at a maximum temperature for 1-3 hours, cooling from a maximum temperature to 600 ° C is carried out at a speed of 30-50 ° C / h and from 600 to 50 ° C at a speed of 50-60 ° C / h. 2. The method according to claim 1, comprising mixing a silica-containing component and an alkaline component, in which caustic soda is introduced in the form of a 46% solution. 3. The method according to claim 2, including drying the granular raw mix, which is carried out at a temperature of 80-250 ° C. 4. The method according to claim 3, comprising crushing the dried granules, which is carried out in a core mixer or ball mill. 5. The method according to claim 4, comprising calcining the silicate mixture, which is carried out in a tunnel furnace or a batch furnace.

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