Method of making heat-insulation blocks. RU patent 2513807.

FIELD: chemistry.

SUBSTANCE: invention relates to production of heat-insulation building materials with closed porosity. Binder solution is prepared first via combined wet grinding of silicate lumps with silica modulus of 1-3 and a silica-containing component with ratio of dry components of 1:1-1:5 and water to solids ratio of 1:1.2-1:4 at temperature of 70-110°C until complete dissolution of the silicate lumps. The silica-containing component is then added to the binder solution until a moulding compound with moisture content of 5-35% is obtained. The moulding compound is granulated and dried. The raw granules are placed in a mould and heated to foaming temperature, followed by annealing. Cooling is carried out at a rate of not more than 4°C per minute.

EFFECT: simple technique of producing heat-insulation materials and low cost of the product.

The invention relates to the production of heat-insulating building materials with the closed porosity, similar to the foam glass.

Known widely used in the industry, the technology of production of foam glass, which includes a glass of special composition, its ground obtaining fine-dispersed the charge, foaming mixture at a temperature of not less than 700°C, that is, when the softening temperature of the glass up to a plastic condition, resulting in the formation of closed pores with walls, consisting of glass rim with crystal inclusions. Ground-up glass is produced from specially welded glass (US, 4192664, CL C03B 19/08, 1980).

Also known technology of production of foamed glass from the purchase of a breakage, tare and other glass by grinding and further expansion (US, 4198224, CL C03B 19/08,1980).

The disadvantage of technologies of reception of foam glass is the high cost of basic raw material is specially made glass or purchased cullet, driven by energy and capital intensive melting glass at a temperature of 1500-1600°C, as well as the consumption of the process of grinding of glass. This causes high cost of foam glass, economically restricting its use in construction, in spite of unique consumer properties.

The direction of expanding the resource base of production of foamed glass materials is the use of affordable siliceous sedimentary rocks, diatomite, opoka, Tripoli, containing fine opal, actively reacts with alkaline reagents are already at low temperatures, which allows to obtain necessary for the formation of closed pores glassy matrix at temperatures foaming material (700-900°C), that allows to reduce energy consumption for melting and grinding.

A significant drawback of the technology, using as alkaline component raw materials from the caustic soda solution, is the high cost of caustic soda as a source of sodium oxide, compared with soda ash used in the manufacture of glass and silicate blocks.

The closest technical solution for the totality essential sign and the achieved result is and how to obtain construction material on the basis of foamed glass / Patent RF №2348596, CL C04B 38/00, publ. 10.03.2009/.

Describes a method for construction material includes the mixture of silica component with total content opal at least 20%, alkaline component, in the form of a solution of sodium hydroxide and water, with regard to the content of alkaline component to the content of silica component from 0.08 to 0.50 for total content silica and alkaline components to the content of water up to 2.0, homogeneous silicate mass, filling silicate mould weight, heating it to a temperature of expansion, cooling expanded silicate mass to the ambient temperature and the extraction of the finished building the material. Before filling in the form of silicate mass is subjected to preliminary swelling by heating it to a temperature of expansion, cooling and grinding, thus cooling swollen mass before removing it from the form perform with a gradual decrease of temperature, providing the temperature difference on the surface and in the centre expanded material that excludes the formation of cracks in the material, the speed of 0,06-2.0°C/min, the temperature of expansion silicate mass is within the temperature range from 450 centigrade C to 900 C.

The disadvantage of this method of obtaining building thermal insulation of a granular material is used as alkaline component expensive raw materials, such as sodium hydroxide, which cost in terms of sodium oxide is much larger than when using alkaline component produced on the basis of soda soda, for example silicate blocks. The high cost of alkaline component leads to the fact that the raw material component of the material exceeds the cost of the purchase of cullet used in the classical technology of production of foamed glass with family consumer properties. In addition, a well-known technology complex, because it involves intermediate drying, crushing and heat treatment, which leads to higher capital costs and energy costs, because it does not allow to fully realize the main advantages of silica-containing raw material used - prevalence, affordability and high reactivity.

Technical task is the simplification of the technologies, the expansion of raw materials, reducing the cost of production while maintaining the specified properties of heat-insulating material on the basis of common siliceous rocks.

The problem is solved so that the method of manufacture of heat-insulating blocks, including the preparation of homogeneous molding material by mixing silica component, alkaline component and water, forming raw granules, drying and high temperature foaming raw granules, according to the invention, pre-prepared binders solution by joint wet grinding silicate blocks with silicate module 1-3 and silica component with a ratio of dry components 1:1-1:5 and vodorodom 1:1,2-1:4 and temperature 70-110°C until dissolved silicate blocks, and then in a binder solution add silica component to obtain molding material humidity W5-35%, then produce a granulating it, drying, then raw pellets placed in a mold and heated to a temperature of foaming with subsequent annealing at cooling with the speed of no more than 4o C per minute.

The proposed method differs from the known composition components and the sequence of technological operations, namely, that pre-prepared binders solution by joint wet grinding silicate-blocks with silicate module 1-3 and silica component with a ratio of dry components 1:1-1:5 and vodorodom 1:1,2-1:4 and the temperature of 70-110°C until dissolved silicate blocks, and then in a binder solution add silica component to obtain moulding mass moisture W5 - 35%, then produce a granulating it, drying, then raw pellets placed in a mold and heated to a temperature foaming with subsequent annealing at cooling with the speed of no more than 4o C per minute.

The proposed method of obtaining material is based on maximum using reactivity opal siliceous earths, reacts with alkaline component on the basis of silicate of sodium in the joint grinding and dissolution, which further stimulates the chemical interaction of components due to the effect of mechanical activation.

As alkaline component that constitutes the main part of raw material costs, use silicate-block, which is obtained through soda ash.

Alkaline component is used to dissolve opal silica component that allows you to increase the number, concentration and silica modulus of a solution of sodium silicate in the liquid phase binder solution and, thus, to reduce the need for alkaline component when saving properties of insulating material.

The proposed method simplifies the technology of production of foamed glass and excludes energy-consuming operation intermediate drying, heat treatment, prior to expand and crushing of semi-finished product, by obtaining plastic molding material prepared by mixing of binder solution with the additional amount of silica component, providing optimal humidity and, accordingly, viscosity mass.

With regard to binding solution and alkaline silica-containing components more than 2:1 unacceptable rising raw material costs and reduced chemical resistance of the material underused reactivity silica component, to convert amorphous silica silica rocks in sodium silicate with higher silicate module.

With respect and alkaline silica-containing component less than 1:5 contents glassy phase after heat treatment becomes insufficient to ensure the closed nature of the porosity and high strength of the material.

The ratio of water and solid components in the raw mix is selected, proceeding from the need to ensure a low enough viscosity raw mix at the stage of obtaining binder solution, but at the same time minimize the amount of dry Tripoli used to reduce moisture content of the mixture on the stage of forming mass.

Optimal ratio of water and solid components depends on the composition of silica component silicate module silicate blocks and chosen operating mode.

When the water content above the specified limit is impossible to provide enough content in forming the mass of sodium oxide, necessary for receiving the minimum required glass rim, while ensuring the desired humidity of forming mass.

When the water content is below the specified limit, the raw meal is not suitable for wet grinding and homogenizing due to high viscosity and does not provide the number of the liquid phase, necessary for reaction education silicates.

It is recommended to use the ratio of total content and alkaline silica-containing component to the water in the optimal range from 1:1.5 to 1:2,2.

Temperature range obtain binder solution is the need to accelerate the formation of silicates on the border of liquid and solid phases, which allows to reduce the duration of hydrothermal processing of the raw mix, but at the same time not to exceed boiling temperature of the reaction mixture at atmospheric pressure, which allows to simplify the technology, not using the equipment working at high pressure.

Building material according to the invention has homogeneous structure and uniform porosity, there are no voids, seals and other defects. High porosity, small sizes of pores and homogeneous structure provide material density, compressive strength, thermal conductivity at the level of more expensive counterparts.

The method is implemented as follows.

Prepared binders solution on the basis of siliceous rocks, silicate blocks and water collected in the following mass relations: a silicate-block/siliceous rock - from 1:1 to 1:3 water/ solids - from 1:5 to 1:1, and, if necessary, foaming components (foaming) on the basis of carbon.

Solid components and water are loaded in the ball mill or attritor wet grinding, which is combined operation of grinding, mixing, dissolution and hydrothermal processing of the reaction mixture, held for 0.5-3 hours at a temperature of 70-110 C. During combined processing occur following processes:

- Mechanical averaging mixture and additional grinding components;

- Heating of the mixture by chemical dissolution components and mechanical mixing;

- Dissolution of granules of a silicate-block in the liquid phase of the solution with the formation of colloidal solution of sodium silicate;

- Chemical dissolution part of siliceous rocks fine opal (amorphous silica) with alkaline liquid solution phase, due to the reaction of silikatobeton in which silica goes into the composition of the liquid phase of the solution.

The distinctive feature of this method is the use of a silicate-block as an alkaline reagent for dissolution opal siliceous rocks. Dissolution of amorphous silica increases the total amount and concentration of silica in the liquid phase binder solution and its silica module (molar ratio to silica dioxide of sodium). This increases the volume of the liquid phase and binding capacity binder solution increases hydrolytic resistance of the final material (protectorate)allows the use of a silicate-block with minimal silicate module (starting with orthosilicate) and significantly reduce the consumption of a silicate-block, as the most expensive raw material per unit of the final product.

Received binder solution is used for preparation of a viscous molding material, which together with the additional number of siliceous rocks (to be placed into the mixer, fitted for mixing of viscous and pasty mixtures, and stirred until a homogeneous paste is obtained from viscosity required plastic molding raw granules (on the chosen design granulator). The ratio binder solution and siliceous rocks chosen from the necessary technological viscosity molding material.

To obtain raw granules forming mass undergoes surgery granulirovanija by plastic molding, including (for example) by extrusion (screw granulator), tabletting (granulator molding), rubs, and pushing through the perforated plate or in any similar way to get raw pellets, of a certain size.

The size of the raw granules is selected based on the required size of granules final material after aeration, and in the manufacture of bulk material on the basis of ease of dosing and filling out the form, and ranges from 1 to 10 mm Dried raw pellets are placed in the form of heat-resistant steel and are foaming at the tunnel kilns, transshipped in the annealing furnace, after which are machined, packaging and sent to the warehouse of finished products.

As silica component use diatomite natural origin the following chemical composition,% Mas.: SiO 2 - 77,5; Al 2 O 3 - 10,3; CaO - 1,3; Fe 2 O 3 - 3,8; other - 7,1.

The mineralogical composition of diatomite,% Mas.:

montmorillonite

plagioclase+orthoclase

As alkaline component use silicate-block of the following chemical composition,% Mas.: SiO 2 - 77,5; Na 2 O - 10,3; other - 7,1.

Siliceous component pre-provisioned, which was drying in the drying chamber at a temperature of 100 degrees C and humidity of 3-5%, crushing to a fraction of 2-3 mm and grinding with the help of the mill up to 100 microns.

Then was prepared binders solution. To do this silica and alkali components in mass ratio of 1:1, and a blowing Supplement - technical carbon in the amount of 1% from weight of solid components were mixed with water temperature of 80 C for bulk water to solid components 1: 2,5, and placed in the drum ball mill, where been grinding for 3 hours at a temperature of 70 to 90 C.

Received binder solution was mixed with additional portion of silica component ratio of 0.5:1 to the dry mass of binder solution before reception of plastic molding material.

Received heat-insulating material is a block with a uniform porosity size 1-3 mm, the volume density of the material is 210 kg/m 3 , the compressive strength is 1.2-1.5 MPa (12-15 kg/cm 2 ), thermal conductivity of 0.45-0.47 W/(m°C), water absorption is not more than 2%.

The received block material can be used for thermal insulation of buildings, constructions and technological equipment, devices warm roofs with high parameters of durability and fire resistance.

A method for insulating blocks, including the preparation of homogeneous moulding mass by mixing silica component, alkaline component and water, forming raw granules, drying and high-temperature foaming raw granules at a temperature of 700-1000°C and then cooled, wherein the pre-prepared binders solution by joint wet grinding silicate blocks with silicate module 1-3 and silica component with a ratio of dry components 1:1-1:5 and vodorodom 1:1,2-1:4 and the temperature of 70-110°C until dissolved silicate blocks, and then in a binder solution add silica component to obtain molding material humidity 5-35%, then produce a granulating it, drying, then raw pellets placed in a mold and heated to a temperature foaming with subsequent annealing at cooling with the speed of no more than 4o C per minute.