RU2234481C2 - Raw mixture for production of air-entrained ceramic articles - Google Patents

Abstract

FIELD: production of cellular ceramics; manufacture of building materials.

SUBSTANCE: proposed raw mixture contains the following components, mass-%: high-calcium flying ash, 50-55; calcium chloride, 0.9-2; NaOH alkaline, 2.3-2.9; aluminum powder, 0.08-0.09; sulfated soap, 0.7-1.4; the remainder being water.

EFFECT: possibility of extraction of technogenious raw material; low cost; enhanced strength.

2 tbl, 1 ex

Description

The present invention relates to the production of cellular ceramics and can be used for the manufacture of building materials.

Closest to the proposed raw mix according to the technical nature and the achieved effect is a raw mix, including in wt.%: Diatomite - 66.5; sawdust - 2.1; rosin - 0.05; sodium hydroxide - 0.008; casein glue - 0.03; water - 31.3 (with the consumption of raw materials (kg) per m ^{3 of} 600 type foam diatomite brick: dry diatomite - 685; sawdust - 21.7; rosin - 0.56; sodium hydroxide - 0.082 and casein glue - 0.32 at a slurry humidity of 50-60%) [1].

The disadvantage of this mixture is the need for natural locally located raw materials requiring grinding, reducing the drying time of the semi-finished product and low strength.

The technical result is the involvement of technogenic raw materials in the production of building materials, reducing the cost of the material and increasing its strength.

The technical result is achieved by the fact that high calcium fly ash with a bulk density of up to 0.14 t / m ^{3 is} used as a silica component, calcium chloride and alkali NaOH are used as additives, aluminum powder and sulfate soap are used as a blowing agent in the following ratio of components , wt.%:

high calcium fly ash 50-55

calcium chloride 0.9-2

alkali NaOH 2.3-2.9

aluminum powder 0.08-0.09

sulfate soap 0.7-1.4

water rest

High-calcium fly ash is formed from burning brown coal (OST 34-70-542-81) of the Irsha-Borodinsky deposit of the Kansk-Achinsk basin and contains, wt.%: SiO ₂ - 40 ... 55; Al ₂ O ₃ - 4 ... 10; Fe ₂ O ₃ - 6 ... 14; CaO - 20 ... 35; MgO - 3 ... 6; K ₂ O - 0.3 ... 1.5; Na ₂ O - 0.2-0.5; SO ₃ - 0.9 ... 5; CaO _St. - 3 ... 13; combustible impurities - not more than 2.

Calcium chloride produced by JSC "Chemical Plant named after L. Ya. Karpov", the Republic of Tatarstan, the city of Mendeleevsk, is a crystalline product.

The manufacture of calcium chloride and its requirements comply with GOST 450-77 "Calcium chlorine. Technical. Technical conditions."

Alkali NaOH produced by JSC "BLPK" is a 40% solution and meets the technical requirements of GOST 2263-71.

Aluminum powder produced by OJSC "BrAZ", Irkutsk region, Bratsk.

The manufacture of aluminum powder and its requirements comply with GOST 5494-71E.

Sulphate soap is a product that is removed from the surface of the black liquors of sulphate-cellulose production when cooking pulp from coniferous and deciduous wood, is a buttery product from dark yellow to dark brown. In accordance with the technical specifications TU 13-0281078-28-118-88, the chemical composition of sulfate soap, wt.%: Fatty, resin acids and unsaponifiable substances - not less than 40-45; water no more than 35 - 50; total alkali in terms of NaOH - not more than 9. Soap is contaminated with lignin, tannides and dyes, as well as mineral components.

The introduction of sulfate soap and aluminum powder provides the formation of combined, differentiated by size porosity and the formation of a balanced raw structure, in which the larger pores created as a result of gas formation are combined with small ones obtained by air entrainment. This determines an increase in the strength and thermal characteristics of the crock.

The introduction of calcium chloride in the feed mixture allows you to accelerate the formation of calcium silicate, to bind free CaO, which will ensure the formation of eutectic melts with a low melting point. When calcium chloride is added to the mass, the reacted sections of CaO grains turn yellow, which is due to the formation of pyroxenes. The formation of feldspars was also noted.

The use of high calcium fly ash as the main raw material component in combination with additives allows the formation of high-strength, long-lasting crystalline phases during firing.

Example

The manufacture of the material is as follows. Water (t = 40 ... 60 ° C) and previously prepared 3% solution of calcium chloride are introduced into fly ash. The mixture is stirred for 2 ... 3 minutes. In a pre-prepared 2.5% solution of sulfate soap, aluminum powder is introduced in an amount, wt.%: 1.5. The finished suspension is introduced into the mixture and stirred for no more than 1 min. Then, a 40% alkali solution of NaOH is introduced in an amount of 2.5%. The mixture is poured into a well-oiled and hermetically-assembled form, the temperature of which is 45-55 ° C. After pouring the mixture, the mold is placed in an oven (t = 40 ° C). After 18-20 hours, cut the "hump" The cooled products are redistributed. Products are fired at a temperature of 1000 ° C. During firing, a smooth rise in temperature is achieved.

The composition of raw mixes and physico-technical indicators of finished products are presented in table. 1 and 2.

Information sources

1. Kitaytsev V.A. Technology of thermal insulation materials. - M.: Stroyizdat, 1970.

Claims (1)

The raw material mixture for the manufacture of porous ceramic products, including fly ash, alkali-containing NaOH component and water, characterized in that high calcium fly ash with a bulk density of up to 14 t / m ^{3 is} used as fly ash, the mixture additionally contains calcium chloride, and as a blowing agent - aluminum powder and sulfate soap in the following ratio of the components of the mixture, wt.%: Specified fly ash 50-55 Calcium Chloride 0.9-2 Alkali NaOH 2.3-2.9 Aluminum powder 0.08-0.09 Sulphate soap 0.7-1.4 Water Else