WO2007133114A1

WO2007133114A1 - Building material and a method for the production thereof

Info

Publication number: WO2007133114A1
Application number: PCT/RU2007/000212
Authority: WO
Inventors: Alexandr Boleslavovich Faschevsky
Original assignee: Merkin, Nikolai Alexandrovich; Pisarev, Boris Vasilievich
Priority date: 2006-05-17
Filing date: 2007-04-27
Publication date: 2007-11-22
Also published as: RU2300506C1

Abstract

The inventive building material relates to construction and insulating building materials and has a porosity ranging from 80 to 95 vol.% at a density ranging from 70 to 400 kg/m3 , a heat-conductivity factor ranging from 0.035 to 0.14 W/(m⋅°C) and a compressive strength ranging from 1 to 100 kgf/cm2 . The inventive material is produced by a method consisting in exposing a silicate mass to a heat action, prior to filling in into moulds, in such a way that a silicate mass whose residual moisture is less than 5% is obtained, in grinding the silicate mass in such a way that the particle size of a main fraction ensuring, while blowing, the specified pore size of less than 3mm is obtained, wherein the silicate mass used for filling the moulds is embodied in the form of the powdered particles of a dry silicate mass, in exposing the ground silicate mass, prior to heating it to a blowing temperature, to a heat action at a temperature ranging from 80 to 600°C for partially removing a chemically combined water in such a way that a partly dehydrated silicate mass is obtained, and in consequently heating said mass up to the blowing temperature associated with the final removal of water, thereby initiating the formation of pores in the silicate mass.

Description

BUILDING MATERIAL AND METHOD FOR PRODUCING IT

FIELD OF THE INVENTION

The invention relates to the field of the construction industry, in particular, to a building material and a method for its production.

The task of obtaining cheap porous inorganic building materials from widespread siliceous rocks has been going on for more than fifty years. The problem is that siliceous rocks practically do not swell. At the same time, siliceous rocks in a mixture with liquid glass swell. Moreover, the melting temperature of such mixtures is 460-550 ⁰ C lower than that of the initial siliceous rocks. At a temperature of 650 ⁰ C and above, such a mixture becomes a viscous fusible. Gases evolved at this temperature, in particular water vapor, swell the mixture, which after cooling gives a porous inorganic material. The pore size in the material depends on the plastic-viscous properties of the mixture, its composition and expansion temperature. The basis of the considered approach is the thermochemical expansion of the silicate mass due to water vapor generated from physical and chemically bound water contained in the silicate mass itself. The described approach is the basis for obtaining porous building materials and methods for their preparation.

State of the art

Known building material and method for its production (see RF patent N ° 2053984, C04B 38/02, 1996). The building material is obtained from an initial mixture containing a silica-containing component, an alkaline component, a zinc-containing component and water with a ratio of the content of the alkaline component to the content of the silica-containing component in the range from 0.4 to 0.5, the total content of silica-containing component and the alkaline component to the water content in the range of values is from 0.8 to 2.2. As a silica-containing component, tripoli, diatomite or flask are used, as an alkaline component - sodium hydroxide, as zinc-containing additives - zinc oxide, zinc sulfate or zinc chloride, as water - tap water. The resulting material has a porosity of 78-89 vol%, a density of 134 to 302 kg / m ³ , a thermal conductivity of 0.074 to 0.098 Wt / (m-° C), and a compressive strength of 2 to 10 kgf / cm ² . The material is of poor quality due to inhomogeneous porosity, namely, there is a significant pore size variation in their size, as well as the presence of voids and seals in the structure of the material. The specified low quality of the material determines the above-mentioned characteristics of the material that are not good enough, namely, its density, compressive strength and thermal conductivity. In particular, a material with a density of 134 kg / m ³ at an acceptable (for a given density) compressive strength of 2 kgf / cm ² has an unacceptably high (for a given density) value of the coefficient of thermal conductivity of 0.074 W / (m- ° C). On the other hand, a material with a density of 302 kg / m ³ at an acceptable value of the coefficient of thermal conductivity of 0.098 Wt / (m- ° C) has a rather low value of compressive strength in the amount of 10 kgf / cm ² . In addition, the material has a high cost due to the high ratio of the alkaline component to the silica-containing component in the initial mixture (0.4-0.5), and also due to the use of a zinc-containing additive in the initial mixture. The use of a zinc-containing additive in the preparation of the initial mixture does not improve the structure of the material. These shortcomings impede the organization of industrial production and limit the widespread use of this material.

The method of obtaining the material consists in mixing a silica-containing component, an alkaline component, a zinc-containing component and water to obtain an initial mixture in which the ratio of the content of the alkaline component to the content of the silica-containing component is in the range from 0.4 to 0.5 and the ratio of the total content silica-containing and alkaline components to the water content is in the range from 0.8 to 2.2. The specified mixture is stirred until a homogeneous mass is obtained, in which silicate formation reactions take place to obtain a silicate mass. The resulting silicate mass is filled into molds, heated to a temperature of 350-400 ° C, at which the mass is swollen, followed by cooling to ambient temperature and the finished building material is removed from the molds. Silicate expansion mass is provided by water vapor. Steam is formed from water obtained by partial dehydration in the specified temperature range of certain types of hydroxides contained in the silicate mass. Also involved in vaporization is physical water in the silicate mass. The disadvantage of this method is the low quality of the material obtained, manifested in the heterogeneity of porosity and an unsatisfactory combination of material characteristics - density, compressive strength and thermal conductivity. The mentioned disadvantage is explained by the fact that physical water and chemically bound water of certain types of hydroxides involved in the process of vaporization are dehydrated at the expansion temperature. Another factor explaining the low quality of the obtained material is that the silicate mass of high humidity is subjected to expansion, the ratio of the total content of silica-containing and alkaline components to the water content is in the range from 0.8 to 2.2, which creates conditions for aggregation (" “adhesion”) particles of mass, which leads to the formation of voids, large pores and interconnected (open) pores.

The closest technical solution for the combination of essential features and the achieved result is the building material and the method of its production, known from the book of V. N. Ivanenko “Building materials and products from siliceous rocks”. - Kiev: Budivelnik, 1978, 120 p.

A well-known building material is obtained from an initial mixture comprising a silica-containing component, an alkaline component and water with a ratio of the content of the alkaline component to the content of the silica-containing component in the range of values from 0.08 to 0.40, the total content of silica-containing component and the alkaline component to the water content in the range of values from 1.6 to 5.3. The resulting material has a porosity of 63-80 vol.%, Density (p) from 300 to 700 kg / and ³ , coefficient (λ) of thermal conductivity from 0.14 to 0.29 Wt / (m- ° C) and compressive strength from 13 to 50 kgf / cm ² . The material has a sufficiently high density value; less dense material cannot be obtained. High density determines a high value of thermal conductivity, which limits the possibility of using the material as a heat-insulating material. The above material is of poor quality due to low and non-uniform porosity, as well as due to the presence of voids and seals in the structure of the material. The low quality of the material is explained by the course of the process of vaporization, in which physical water and chemically bound water of some types of hydroxides participate, dehydrating at the expansion temperature. This, as well as supply to the swelling of the moist silicate mass, leads to inhomogeneous porosity and the formation of voids and seals in the structure of the material. The low quality of the material determines the low rates of the above characteristics of the material, namely, its density, compressive strength and thermal conductivity. In particular, a material with a density of 300 kg / m ³ has a low (for a given density) compressive strength of about 13 kgf / cm ² and an unacceptably high (for a given density) value of the thermal conductivity of about 0.14 W / (m- ° C). Heavier material with a density of 550 cr / m ³ also has insufficient strength of the order of 27 kgf / cm ² and a very high value of the thermal conductivity of about 0.21 W / (m- ° C). These shortcomings impede the organization of industrial production and limit the widespread use of this material.

The method of obtaining the material is that a silica-containing component, an alkaline component and water are mixed to obtain an initial mixture in which the ratio of the content of the alkaline component to the content of the silica-containing component is in the range from 0.08 to 0.40 and the ratio of the total content of silica-containing and alkaline components to the water content is in the range of values from 1, 6 to 5.3. Before mixing, the physical water is partially removed from the silica-containing component (dried) and then ground to a basic fraction of less than 0.14 mm. The mixture of the starting components is mixed and a homogeneous mass is obtained, which is held for at least two hours for the formation of silicate reactions and to obtain a silicate mass, which is filled into molds and heated to its expansion temperature in the temperature range 650-900C ⁰ , followed by cooling to ambient temperature and removing from forms of building material. The expansion of the silicate mass is ensured by water vapor. Steam is formed from water obtained by partial dehydration in the specified temperature range of certain types of hydroxides contained in the silicate mass. Physical water is also involved in vaporization, located in the silicate mass. The disadvantage of this method is the low quality of the material obtained, which is manifested in the heterogeneity of porosity and an unsatisfactory combination of material characteristics - density, compressive strength and thermal conductivity. This drawback is due to the fact that in the method in the process of vaporization, both physical water and chemical water of certain types of hydroxides are involved, dehydrating at the expansion temperature. Another factor affecting the low quality of the obtained material is that the silicate mass of high humidity is subjected to expansion, the ratio of the total content of silica-containing and alkaline components to the water content is in the range from 1.6 to 5.3. This creates the conditions for aggregation ("gluing") of the particles of the mass, which leads to the formation of voids, large pores and communicating (open) pores.

SUMMARY OF THE INVENTION

The basis of the invention is the task of improving the operational characteristics of a building material based on widely available siliceous rocks.

The problem is solved in that in a method of obtaining a building material, comprising mixing a silica-containing component, an alkaline component and water with a ratio of the content of the alkaline component to the content of the silica-containing component from 0.08 to 0.40 and a ratio of the total content of silica-containing and alkaline component to the water content to 5.3 to obtain a homogeneous silicate mass, filling it with a mold and heating to a temperature of expansion of the silicate mass, followed by cooling to ambient temperature medium and extracting the finished building material from the mold, the resulting silicate mass is subjected, before filling the mold, to temperature exposure to a residual moisture content of less than 5 wt.%, grinding to a particle size of not more than 100 μm, which ensures pore size less than 3 mm when swelling, after filling the mold, to heating to 600 ° C with partial dehydration of the specified mass, then heated to a swelling temperature in the range from 650 to 900 ⁰ C, and to cooling - with a gradual decrease in temperature according to the regime: to 580 ° C with a speed not higher 2 ° C / min, up to 250 ⁰ C - not higher than 8 ° C / min, up to 20 ⁰ C - not higher than l, 5 ° C / min. Moreover, the ratio of the total content of silica-containing and alkaline components to the water content is at least 0.8, the specified grinding is carried out to a particle size of less than 80 microns, heating to 600 ⁰ C is carried out in the temperature ranges up to 165 ⁰ C, from 165 to 220 ⁰ C, from 230 to 350 ⁰ C, of 450 to 600 ° C in any of their sequence, partial dehydration of said mass is effected by dehydration of hydroxides of iron and aluminum contained in the silicate weight, swelling is effected by the final disposal of chemical bonds -water.

The problem is also solved by the fact that the building material obtained from the initial mixture containing a silica-containing component, an alkaline component and water with a ratio of the content of the alkaline component to the content of the silica-containing component from 0.08 to 0.40 and the ratio of the total content of silica-containing and alkaline components to the content water to 5.3, obtained by the above method and has a porosity in the range of values from 80 to 95 vol.% at a density of 70 to 400 kg / m ³ , thermal conductivity from 0.035 to 0.14 W / (m ° C) and Ruggedness upon compression from 1 to 100 kgf / cm ^2.

When the ratio of the content of the alkaline component to the content of the silica-containing component is less than 0.08, the resulting material has a reduced porosity, less than 80%, increased strength, more than 400 kg / m ³ and an increased coefficient of thermal conductivity, more than 0.14 W / (m- ° C). If the value of the specified ratio is more than 0.40, the cost of the material becomes unacceptably high due to the high content of the expensive alkaline component.

When the ratio of the total content of the silica-containing component and the alkaline component to the water content is more than 5.3, the lack of water affects the quality of the reactions of silicate formation, and also complicates the process of homogenization of the initial mixture.

On the other hand, the ratio of the total content of the silica-containing component and the alkaline component to the water content should be at least 0.8. In case the value specified ratios of less than 0.8 a significant role begin to play the cost of the subsequent removal of excess water.

It is recommended to use the indicated ratio in the range of 3.5 - 4.2, which, on the one hand, ensures effective homogenization of the mixture and the occurrence of silicate formation reactions in it, and, on the other hand, saves energy costs for the removal of physical water at subsequent stages of the method. The building material, according to the invention, has a uniform structure, uniform porosity, there are no voids, seals and other defects. High porosity, small pore sizes and a uniform structure provide the material with the best previously unattainable values of density, compressive strength, and thermal conductivity. The cost of the obtained material is quite low, which is ensured primarily by the low alkaline content in the initial mixture. A material of this quality has wide industrial applications. Conventionally, the materials of this series according to the combination of characteristics density, compressive strength, thermal conductivity can be divided into three types (see table):

Table

The material according to the invention, as a heat-insulating material, can be used for thermal insulation of structures of buildings and structures, various industrial installations, equipment, refrigerators, pipelines and vehicles. The material according to the invention, as structural heat-insulating material, can be used to make self-supporting fences and lintels for the construction of low-rise residential, administrative and industrial buildings and structures. Moreover, additional thermal insulation of structures made of this material is not required.

SUBSTITUTE SHEET (RULE 26) The material according to the invention, as a structural material, can be used as a supporting building material for the construction of low-rise residential, administrative and industrial buildings and structures. Moreover, additional thermal insulation of structures made of this material is not required.

Preferably, when the ratio of the total content of silica-containing and alkaline components to the water content is at least 0.8.

Partial removal of chemically bound water is ensured by the dehydration of iron and aluminum hydroxides contained in the silicate mass.

The final removal of chemically bound water is ensured by the dehydration of silicon hydroxides contained in the silicate mass.

The expansion temperature lies in the temperature range 650 - 900 ⁰ C.

This implementation of the method allows to obtain building material with the claimed characteristics. This is due to the fact that the method uses only one source for vaporization - chemical water, which is part of silicon hydroxide, the dehydration of which occurs at a temperature of expansion. All other possible sources of water for vaporization, in particular, physical water is removed at the stage of obtaining silicate mass with a residual moisture content of less than 5 wt.%, Chemically bound water is removed at the stage of obtaining partially dehydrated silicate mass, when in the temperature range 80 ° C - 600 ° C there is a dehydration of iron and aluminum hydroxides. Another factor influencing the achievement of the characteristics of the claimed building material is that the dry silicate mass in the form of crushed particles is expanded, which contributes to the formation of uniform porosity and reduces the likelihood of voids, large pores, seals and interconnected (open) pores.

DETAILED DESCRIPTION OF THE INVENTION

The method is implemented as follows.

As a silica-containing component for the preparation of the initial mixture, sedimentary or volcanic-sedimentary siliceous rocks are used: diatomites, spongolites, radiolarites, silicoflagellites, flasks, tripoli, zeolites, siliceous loams and their transitional varieties, including those with a clay component in the form of montmorillonite, montmorillonite-hydromica, kaolinite-montmorillonite hydromassite, kaolin.

The silica-containing component has the following chemical composition, in wt.%:

SiO ₂ (amorphous silica) 30 - 98

Al ₂ O ₃ 0.1 - 20

Fe ₂ O ₃ 0.1 - 12 inevitable impurities 1.8 - 38

To prepare the initial mixture, a silica-containing component of natural humidity is used, which eliminates the need for preliminary drying and milling, which saves the corresponding energy costs compared to the closest analogue. This possibility is provided due to the redistribution of part of the chemical reactions in subsequent stages. In this case, the water contained in the initial silica-containing component is taken into account when calculating the ratio of the total content of the silica-containing component and the alkaline component to the water content.

Sodium hydroxide or potassium hydroxide is used as the alkaline component. In this case, the alkaline component is introduced in the form of an aqueous solution. It is recommended to use commercially available solutions.

As water use tap water or water intended for the preparation of mortars. When the ratio of the content of the alkaline component to the content of the silica-containing component is less than 0.08, the resulting material has a reduced porosity and an increased coefficient of thermal conductivity, which limits the practical use of the material. If the value of the specified ratio is more than 0.40, the cost of the material becomes unacceptably high due to the high content of the expensive alkaline component.

When the ratio of the total content of the silica-containing component and the alkaline component to the water content is more than 5.3, the lack of water affects the quality of the reactions of silicate formation, and also complicates the operation of homogenization of the initial mixture. On the other hand, the ratio of the total content of the silica-containing component and the alkaline component to the water content should be at least 0.8. If the value of this ratio is less than 0.8, the costs of the subsequent removal of excess water begin to play a significant role.

It is recommended to use the indicated ratio in the range of 3.5 - 4.2, which, on the one hand, ensures effective homogenization of the mixture and the occurrence of silicate formation reactions in it, and, on the other hand, saves energy costs for the removal of physical water in the subsequent stages.

The initial mixture is mixed in a mixer until a homogeneous mass is obtained. A silicate homogeneous mass placed on pallets or on a conveyor is fed into the drying chamber, where physical water is removed to obtain a silicate mass with a residual moisture content of less than 5 wt.%. In the indicated temperature range, the reactions of silicate formation proceed much faster (tens of times) than under ambient temperature conditions. If the residual moisture content of the silicate mass is more than 5 wt.%, It may be difficult to grind it to the required particle size.

Dry silicate mass with a residual moisture content of less than 5 wt.% Is subjected to grinding in a mill. If necessary, before feeding into the mill, the dry silicate mass can be crushed to the size of the pieces with which the mill of the accepted type works. The silicate mass is crushed to a particle size of the main fraction, which ensures a predetermined pore size of less than 3 mm during expansion.

To ensure a predetermined pore size in the building material, the dry silicate mass is crushed to a size of the main fraction of less than 0.8 mm. In this case, the following dependence is observed - the finer the grinding of the silicate mass, the finer the pores of the material. It is recommended to grind the dry silicate mass to the size of the main fraction within. 30 - 80 microns. With such grinding, a good ratio between the energy consumption for grinding and the resulting operational characteristics of the material is ensured. Then, a silicate mass, which is a crushed particle of a dry silicate mass, is filled into forms that, when expanded, will provide the desired shape of the resulting building material. Using forms building materials can be shaped into blocks of various sizes, shapes of segments, shells for insulation of pipelines and other other forms. The crushed silicate mass filling the molds is subjected to temperature in the temperature range from 8O ⁰ C to 600 ⁰ C to partially remove chemically bound water. The purpose of this heat treatment is to remove chemically bound water through the dehydration of iron and aluminum hydroxides. The result of this processing operation is a partially dehydrated silicate mass, i.e. silicate mass dehydrated by iron and aluminum hydroxides. Partial removal of chemically bound water at a temperature of less than 80 ⁰ C and more than 600 ⁰ C does not make sense, since in this case the reaction of dehydration of iron and aluminum hydroxides is not observed. Hydroxides of iron and aluminum are mainly formed at the stage of silicate formation during the interaction with water of iron and aluminum oxides contained in the initial silica-containing component. The silicate mass hydroxides under consideration are represented by various types of compounds and their phase states, characterized by different dehydration temperatures. To ensure the required dehydration, mandatory temperature treatments are carried out in four temperature ranges. The temperature effect in the temperature range from 8O ⁰ C to 165 ⁰ C provides mainly the dehydration of iron hydroxide of the form FeO (OH), in particular, its α-, β-, γ- and δ-phases. The temperature effect in the temperature range from 165 ° C to 220 ⁰ C mainly ensures the dehydration of aluminum hydroxide of the type Al (OH) ₃ , in particular, its phase states in the form of gibbsite and bayerite, as well as iron hydroxide of the type FeO (OH), in particular its os phase. Temperature exposure in the temperature range from 23O ⁰ C to 35O ⁰ C provides mainly the dehydration of certain iron hydroxides in certain phase states, as well as the dehydration of certain aluminum hydroxides, including those in the phase state in the form of boehmite. Temperature exposure in the temperature range from 450 ⁰ C to 600 ⁰ C also provides for the dehydration of certain iron and aluminum hydroxides in certain phase states.

The partially dehydrated silicate mass, namely, the silicate mass dehydrated by iron and aluminum hydroxides, is exposed to temperature at the expansion temperature. Swelling silicate mass is accompanied by the final removal of chemically bound water, causing the formation of pores in the silicate mass. Water resulting from the dehydration of silicon hydroxides turns into steam, which provides the formation of pores in the silicate mass, i.e. her bloating. With expansion, the initial volume occupied by the silicate mass increases several times.

The expansion of the silicate mass is carried out in the temperature range from 650 ⁰ C to 900 ⁰ C. The expansion temperature affects some characteristics of the resulting material. In particular, the higher the expansion temperature, the lower the rate of water absorption of the material.

The expanded silicate mass is gradually cooled to ambient temperature. It is necessary to gradually lower the temperature so that the expanded material does not crack. The following cooling mode is recommended. Cooling to 58O ⁰ C is carried out at a speed not exceeding 2 ° C / min, cooling to 250 ⁰ C - at a speed not exceeding 8 ° C / min, cooling to ambient temperature, for example to 20 ⁰ C - at a speed not exceeding l, 5 ° C / min. For guaranteed obtaining of high-quality non-cracked material, it is recommended to carry out uniform natural cooling of the material in a furnace disconnected from heating, in which partially dehydrated silicate mass was expanded

The resulting building material is removed from the molds and can be used for its intended purpose. If necessary, the material can be cut into products of the required shapes and sizes. If necessary, you can get building material in various colors. For these purposes, depending on the desired color, salts of various metals are added to the initial mixture. The claimed building material refers to inorganic, non-combustible, environmentally friendly, mechanically strong, bio-, weather- and acid-resistant, durable and effective building and heat-insulating materials with low thermal conductivity.

The material can be used for thermal insulation of structures of buildings and structures, various industrial installations, equipment, refrigerators, pipelines and vehicles. Also, the claimed material can be used as structural and thermal insulation for construction structures of buildings and structures, performing both structural and thermal insulation functions.

If necessary, the material can be produced not only in pieces (blocks, plates), but also in bulk (granules) form. Other objectives and advantages of the invention will become more apparent from the following specific examples of its implementation.

Example 1

Tripoli of a natural deposit of the following chemical composition, in wt.%, Was taken as a silica-containing component:

SiO ₂ (amorphous silica) 78.7

Al ₂ O ₃ 13.2

Fe ₂ O ₃ OD inevitable impurities 8.0.

An aqueous solution of sodium hydroxide concentration of 46% was used as the alkaline component.

As the water used tap water.

To prepare the initial mixture, caustic soda was taken in an amount of 0.4 with respect to tripoli. The ratio of total tripoli and caustic soda to water content was 1.2. The calculation of the amount of water includes water included in the sodium hydroxide solution, as well as water, which constitutes the natural (career) moisture of tripoli.

The specified initial mixture using a mixer was mixed until homogeneous. Then a homogeneous mixture on a tray was placed in a drying chamber, with which physical water was removed and a silicate mass with a residual moisture content of 1 wt.% Was obtained.

The dry silicate mass was crushed using a crusher to a fraction of 2-3 mm, and then crushed to a basic fraction of 30 μm using a mill. The crushed particles of silicate mass were filled into a rectangular metal mold and placed in a muffle furnace. The silicate mass was heated to 15O ⁰ C and held for 9 hours, which ensured mainly the dehydration of iron hydroxide of the form FeO (OH), in particular, its α-, β-, γ- and δ-phases. Then they raised the temperature to 170 ° C and stood for 7 hours, which provided mainly dehydration of certain types of complex compounds based on iron hydroxide. Then the temperature was raised to 19O ⁰ C and held for 6 hours, which ensured mainly the dehydration of aluminum hydroxide of the form Al (OH) ₃ , in particular, its phase states in the form of gibbsite and bayerite.

Then the temperature was raised to 25O ⁰ C and held for 8 hours, which ensured mainly the dehydration of certain aluminum hydroxides, including those in a phase state in the form of boehmite. Then the temperature was raised to 320 ^° C and held for 7 hours, which ensured mainly the dehydration of certain iron hydroxides in certain phase states. Then the temperature was raised to 580 ^° C and held for 6 hours, which ensured the dehydration of the remaining certain iron and aluminum hydroxides in certain phase states. Then the temperature was raised to 72O ⁰ C and held for 3 hours, which ensured the dehydration of silicon hydroxides, the formation of water vapor and the formation of pores, i.e. bloating mass. Then the heating element of the furnace was turned off and the material was allowed to naturally cool in a closed furnace to a temperature of 45 ° C for 12 hours, after which it was removed from the mold.

The cooled block of the obtained building material of 250x250x250 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. The pore size was 1 mm. The porosity of the material was 92 vol%, the density was 90 kg / m ³ , the thermal conductivity coefficient was 0.038 Wt / (m- ° C), and the compressive strength was 3 kgf / cm ² .

The resulting building material refers to heat-insulating building materials. The material can be effectively used for thermal insulation of structures of buildings and structures, various industrial plants, equipment, refrigerators, pipelines and vehicles.

Example 2

The initial mixture was prepared from the same components as in example 1. The ratio of caustic soda to tripoli is 0.35. The ratio of the total content of tripoli and caustic soda to the water content is 3.5. A silicate mass with a residual moisture content of 4 wt.% Was obtained in the drying chamber. The dry silicate mass was ground to a basic fraction of 70 μm. The silicate mass was heated to 145 ° C and held for 10 hours, which ensured mainly the dehydration of iron hydroxide of the form FeO (OH), in particular, its α, β, γ, and δ phases. Then the temperature was raised to 17O ⁰ C and held for 6 hours, which ensured mainly the dehydration of some types of complex compounds based on iron hydroxide. Then the temperature was raised to 19O ⁰ C and held for 6 hours, which ensured mainly the dehydration of aluminum hydroxide of the form Al (OH) ₃ , in particular, its phase states in the form of gibbsite and bayerite.

Then the temperature was raised to 25O ⁰ C and held for 6 hours, which ensured mainly the dehydration of certain aluminum hydroxides, including those in a phase state in the form of boehmite. Then the temperature was raised to 320 ^° C and held for 6 hours, which ensured mainly the dehydration of certain iron hydroxides in certain phase states. Then, the temperature was raised to 580 ° C and held for 6 hours, which ensured the dehydration of the remaining certain hydroxides of iron and aluminum in certain phase states. Then the temperature was raised to 700 ⁰ C and held for 3.5 hours, which ensured the dehydration of silicon hydroxides, the formation of water vapor and the formation of pores, i.e. bloating mass. Then the heating element of the furnace was turned off and the material was allowed to cool naturally for 15 hours in a closed furnace to a temperature of 35 ⁰ C, after which it was removed from the mold.

The cooled block of the obtained building material with a size of 250x250x250 mm was removed from the mold and cut into several parts. The structure of the material is homogeneous, the porosity of the material is uniform, there are no voids and densities. The pore size was 1.3 mm. The porosity of the material was 89 vol%, density 150 kg / m ³ , thermal conductivity coefficient from 0.041 W / (m- ° C), compressive strength 10 kgf / cm ² .

Example 3 The flask of a natural deposit of the following chemical composition, in wt.%, Was taken as a silica-containing component:

SiO ₂ (amorphous silica) 54.5

Al ₂ O ₃ 8.9

Fe ₂ O ₃ 0.3 inevitable impurities 36.3.

The ratio of caustic soda to tripoli was 0.30. The ratio of the total content of tripoli and caustic soda to the water content was 4.0.

A silicate mass with a residual moisture content of 4 wt.% Was obtained in the drying chamber. The dry silicate mass was ground to a basic fraction of 60 μm. The silicate mass was heated to 155 ° C and held for 12 hours, which ensured mainly the dehydration of iron hydroxide of the form FeO (OH), in particular, its α, β, γ, and δ phases. Then the temperature was raised to 170 ° C and held for 8 hours, which ensured mainly the dehydration of some types of complex compounds based on iron hydroxide. Then the temperature was raised to 19O ⁰ C and held for 8 hours, which ensured mainly the dehydration of aluminum hydroxide of the form Al (OH) ₃ , in particular, its phase states in the form of gibbsite and bayerite. Then the temperature was raised to 25O ⁰ C and held for 8 hours, which ensured mainly the dehydration of certain aluminum hydroxides, including those in a phase state in the form of boehmite. Then the temperature was raised to 320 ^° C and held for 8 hours, which ensured mainly the dehydration of certain iron hydroxides in certain phase states. Then the temperature was raised to 600 ⁰ C and held for 8 hours, which ensured the dehydration of the remaining certain hydroxides of iron and aluminum in certain phase states. Then the temperature was raised to 68O ⁰ C and held for 4 hours, which ensured the dehydration of silicon hydroxides, the formation of water vapor and the formation of pores, i.e. bloating mass. Then the heating element of the furnace was turned off and the material was allowed to cool naturally for 24 hours in a closed furnace to a temperature of 30 ⁰ C, after which it was removed from the mold.

The cooled block of the obtained building material with a size of 250 ^x 250 ^x 250 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 density. Pore size 1.3 mm. The porosity of the material was 87 vol.%, The density was 240 kg / m ³ , the thermal conductivity was from 0.065 Wt / (m-° C), and the compressive strength was 27 kgf / cm ² .

Received building material, which relates to structural and heat-insulating building materials. The material can be effectively used to make self-supporting fences and lintels during the construction of low-rise residential, administrative and industrial buildings and structures. Moreover, additional thermal insulation of structures made of this material is not required.

Example 4

The diatomite of the natural deposit of the following chemical composition, wt.%, Was taken as a silica-containing component:

SiO ₂ (amorphous silica) 71.4

Al ₂ O ₃ 17.2

Fe ₂ O ₃ 3.0 inevitable impurities 8.4.

A silicate mass with a residual moisture content of 5 wt.% Was obtained in the drying chamber. The dry silicate mass was crushed to a basic fraction of 100 μm. The silicate mass was heated to 150 ° C and held for 8 hours, which ensured mainly the dehydration of iron hydroxide of the type FeO (OH), in particular, its α, β, γ, and δ phases. Then the temperature was raised to 175 ° C and held for 8 hours, which ensured mainly the dehydration of some types of complex compounds based on iron hydroxide. Then the temperature was raised to 190 ° C and held for 6 hours, which ensured mainly the dehydration of aluminum hydroxide of the form Al (OH) ₃ , in particular, its phase states in the form of gibbsite and bayerite.

Then the temperature was raised to 250 ° C and held for 7 hours, which ensured mainly the dehydration of certain aluminum hydroxides, including those in the phase state in the form of boehmite. Then the temperature was raised to 320 ° C and held for 7 hours, which ensured mainly the dehydration of certain iron hydroxides in certain phase states. Then the temperature was raised to 600 ° C and held for 6 hours, which ensured the dehydration of the remaining certain iron and aluminum hydroxides in certain phase states. Then the temperature was raised to 69O ⁰ C and held for 5 hours, which ensured the dehydration of silicon hydroxides, the formation of water vapor and the formation of pores, i.e. bloating mass. Then the heating element of the furnace was turned off and the material was allowed to cool naturally for 24 hours in a closed furnace to a temperature of 30 ⁰ C, after which it was removed from the mold.

The cooled block of the obtained building material with a size of 250x250 ^χ 250 mm was removed from the mold and cut into several parts. The structure of the material is homogeneous, the porosity of the material is uniform, there are no voids and densities. The pore size was 1.7 mm. The porosity of the material was 81 vol.%, The density was 370 kg / m ³ , the thermal conductivity was from 0.095 Wt / (m- ° C), and the compressive strength was 78 kgf / cm ² .

The resulting building material relates to structural building materials. The material can be effectively used as a supporting building material for the construction of low-rise residential, administrative and industrial buildings and structures. Moreover, additional thermal insulation of structures made of this material is not required.

Claims

CLAIM

1. A method of obtaining a building material, comprising mixing a silica-containing component, an alkaline component and water with a ratio of the content of alkaline component to the content of silica-containing component from 0.08 to 0.40 and the ratio of the total content of silica-containing and alkaline component to water content up to 5.3 to obtain homogeneous silicate mass, filling it with a mold and heating to a temperature of expansion of the silicate mass, followed by cooling to ambient temperature and removing the finished form a building material, characterized in that the homogeneous silicate mass is subjected to temperature treatment until the residual moisture content is less than 5 wt.% and grinding to a particle size that ensures pore size less than 3 mm when swelling and after heating the mold to 600 ⁰ C s partial dehydration of the specified mass and subsequent heating to a swelling temperature.

2. The method according to p. 1, characterized in that the ratio of the total content of silica-containing and alkaline components to the water content is at least 0.8.

3. The method according to p. 1, characterized in that the grinding is carried out to a particle size of less than 800 microns.

4. The method according to p. 1, characterized in that the heating to 600 ⁰ C is carried out in the temperature ranges up to 165 ° C, from 165 to 22O ⁰ C, from 230 to 35O ⁰ C, from 450 to 600 ⁰ C in any sequence .

5. The method according to p. 1, characterized in that the expansion temperature is in the range from 650 to 900 ⁰ C.

6. The method according to p. 1, characterized in that the cooling of the expanded silicate mass to ambient temperature is carried out with a gradual decrease in temperature according to the regime: to 580 ⁰ C with a speed of not higher than 2 ° C / min, to 250 ° C - not higher than 8 ° C / min, up to 2O ⁰ C - not higher than l, 5 ° C / min.

7. Building material obtained from an initial mixture containing a silica-containing component, an alkaline component and water with a ratio of the alkaline component to the silica-containing content component from 0.08 to 0.40 and the ratio of the total content of silica-containing and alkaline components to the water content of up to 5.3, characterized in that it is obtained by the method according to any one of paragraphs 1 to 6 and has a porosity in the range from 80 to 95 about % at a density of 70 to 400 kg / m ³ , a thermal conductivity coefficient of 0.035 to 0.14 Wt / (m- ° C) and compressive strength of 1 to 100 kgf / cm ² .

8. The material according to p. 7, characterized in that the ratio of the total content of silica-containing and alkaline components to the water content is at least 0.8.