RU2451644C1 - Method of producing structural heat-insulating foamed glass - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to structural materials. A silica-containing component is mixed with soda ash and/or potash and an alkali solution. The total amount of alkali metal oxides ranges from 8 to 30 wt % of the weight of the dry silica-containing component. The amount of alkali metal oxide, which is added in form of alkali, ranges from 2 to 12 wt % of weight of the dry silica-containing component. After mixing, the mass is granulated and thermally treated at temperature 500-600°C. The obtained mixture is ground and annealed at temperature 700-850°C.

EFFECT: low consumption of expensive alkali, easier process of mixing the charge mixture and reduced sticking of the charge mixture to elements of the mixer.

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Description

The invention relates to the field of the construction industry, in particular to a method for producing building material from widespread and affordable raw materials.

A known method of obtaining structural heat-insulating foam glass, comprising mixing a silicon-containing component, for example tripoli, solution of alkali (the ratio of the number of alkali metal oxide introduced in the form of alkali to the dry silica component is from 0.08 to 0.3) with obtaining a homogeneous mass, its exposure to form silicates and subsequent firing, while drying the siliceous rock, heat treatment at 250-700 ° C for at least 0.5 hours, grinding to a fraction of less than 5 mm, then the specified mixture The indicated exposure is carried out at a temperature of from 0 to 150 ° C for at least 0.2 hours, then drying, crushing and repeated heat treatment are carried out at 250-700 ° C for at least 0.5 hours, after which the material is crushed the resulting mixture is poured into molds and expanded by firing at 680 ° C to produce foam glass (see Patent RU 2333176, published September 10, 2008).

The disadvantage of the described method is the high consumption of expensive alkali, in addition, when mixing a silicon-containing component and an aqueous solution of alkali with an alkali to silicon-containing component ratio of more than 13 wt.%, A sticky mass is formed, which makes it difficult to mix, a strong sticking of the mixture to the working bodies of the mixer, and when the residual wet mass dries, it is on the internal cavities of the mixer, and cleaning this equipment is very difficult.

The technical result is to reduce the consumption of expensive alkali, facilitating the process of mixing the mixture and reducing its sticking to the elements of the mixer.

The technical result is achieved due to the fact that the method of producing foam glass includes mixing the crushed silica-containing component with an alkali solution, heat treatment, grinding and firing at a temperature of 700-850 ° C, moreover, the silica-containing component with soda ash and / or potash and alkali solution, and the total amount alkali metal oxides introduced with these components is from 8 to 30 wt.% by weight of the dry silica-containing component (which corresponds to the ratio of dry alkali to dry silica component in the range from 10% to 40%), while the amount of alkali metal oxide introduced in the form of alkali is from 2 to 12 wt.% by weight of the dry silica-containing component, the mixture obtained after mixing is granulated and heat treated at a temperature of 500- 600 ° C, the resulting mixture is ground and fired.

A method of obtaining high-quality foam glass is proposed as follows.

The silicon-containing component is mixed with soda ash (Na ₂ CO ₃ ) or potash (K ₂ CO ₃ ), which replaces most of the alkali. In the process of mixing, a mixture is obtained that does not have a strong stickiness and does not impede the mixing of the components. Then, a small amount of alkali (NaOH, KOH) is added to the resulting mixture, which does not lead to any problems with stirring. The resulting mixture is pressed into granules on a pellet mill. The granules are processed in a rotary kiln at a temperature of 500-600 ° C, and then grind in a core mixer. In addition to grinding, powder homogenization occurs. The powder thus obtained is poured into metal molds and installed in a kiln. Chemical processes of silicate formation take place in the kiln, and the presence of alkali, whose melting point is about 400 ° C, creates favorable conditions for silicate formation, as well as the release of gaseous components at temperatures from 700 to 850 ° C.

With this technology, most of the alkali, the production of which is complex and expensive, is replaced by more affordable and cheaper soda ash, and the technological equipment works stably due to the absence of adherence of the charge to the working bodies.

An example implementation of the method.

Obtaining foam glass was carried out as follows. The extracted silica-containing raw material (tripoli) of career moisture was passed through an clay grinder and fed into a dryer drum, where it was dried at a temperature of 200-250 ° C for 30 minutes. The dried raw material was fed to the grinding mill for aerofol type, where it was crushed to a fraction of less than 2 mm. After grinding, the raw materials were mixed in a mixer with dry soda ash (or potash) for about 20 minutes. Then, an alkali solution was added to this mixture, and the mixing process was continued until a homogeneous mass was obtained. The resulting mixture was passed through a pellet mill. The diameter of the holes on the perforated grate was about 15 mm. The granules were fed by a conveyor into a rotary kiln in which they were kept for 40 minutes at a temperature of 500-600 degrees. After unloading from the furnace, the granules were cooled and poured into a core mixer. Ground powder was poured into metal molds and mounted on roasting trolleys.

Trolleys were driven through a tunnel kiln at a temperature of 780 ° C. After cooling to a temperature of 20-30 ° C, the metal form was opened and the resulting foamglass block was removed.

The table shows the composition of the charge and the properties of the obtained foam glass.

Table The mixture composition of the mixture Properties of the obtained foam glass. Tripoli dry 100% Density 380 kg / m3 Na ₂ O (as alkali solution) / Tripoli 6.2% Thermal conductivity 0.098 W / m deg K ₂ O (as potash) / tripoli 12% Compressive Strength 60 kgf / cm2 Tripoli dry 100% Density 420 kg / m3 Na ₂ O (in the form of a solution of alkali) / tripoli 3.8% Thermal conductivity 0.1 W / m hail Na ₂ O (as soda) / tripoli 8% Compressive Strength 65 kg / cm2 K ₂ O (as potash) 3% Tripoli dry 100% Density 320 kg / m3 Na ₂ O (in the form of a solution of alkali) / tripoli 7.5% Thermal conductivity 0,091 W / m hail Na ₂ O (as soda) / tripoli 7.1% Compressive Strength 55 kgf / cm2

Claims (1)

A method of obtaining structural and heat-insulating foam glass, comprising mixing the crushed silica-containing component with an alkali solution, heat treatment, grinding and firing at a temperature of 700-850 ° C, characterized in that the silica-containing component is mixed with calcined soda and / or potash and alkali solution, the total amount alkali metal oxides introduced with these components is from 8 to 30 wt.% by weight of the dry silica-containing component, while the amount of alkali metal oxide introduced in the form of alkali, it is from 2 to 12 wt.% by weight of the dry silica-containing component, the mixture obtained after mixing is granulated and heat treated at a temperature of 500-600 ° C, the resulting mixture is ground and roasted.