SU1315441A1 - Method for preparing cellular concrete mix - Google Patents

Abstract

The invention relates to the construction materials industry, in particular to the manufacture of autoclaved cellular concrete. The aim of the invention is to increase the stability and homogeneity of the porous structure, as well as increase the strength of the be, tone. The method consists in the fact that, when milled, ash is added to the nepheline sludge, previously treated with fluoride at a ratio of zolagfluoroanhydride 1: (0.1-0.4), and grinding is carried out at B / T 0.4-0.5 b stages, and in the first stage the treated ash is introduced at a ratio of nepheline sludge: ash 1: (0.8-1), the mixture is crushed to obtain a fraction of 200 µm, and in the second stage, the treated ash is added to nepheline sludge: ash 1; (2-3) and finally ground the mixture to obtain a fraction of 80 µm in the presence of calcium chloride solution. The application of the method allows to increase the strength of products by 90%, to reduce the bulk weight. Table I Q (L cond 4 4

Description

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The invention relates to the industry of building materials, in particular to the production of cellular concrete.

The purpose of the invention is to increase the stability and homogeneity of the porous structure, as well as increase the strength of concrete.

Preliminary mixing of ash and fluoroanhydrite in the ratio of 1: (0.1-0.4) makes it possible to reduce the negative effect of free calcium oxide. When the ratio of ash and fluoroanhydrite is 1: 0.09, the free oxide in the sol is not completely quenched and the products are destroyed. When the content of fluoroanhydrite, providing the ratio of ashes and fluoroanhydrite is 1: 0.5, there is an excess of acid and, as a consequence, a sharp decrease in the strength of the products ,.

The introduction of activated ash of Kansk Achinsk coals in the ratio of nepheline sludge and ash in the first stage: (0.8-1) allows the nepheline sludge to be evenly crushed and prevents its particles from sticking together. When the ratio of nepheline sludge and ash 1: 0.7, sticking of a part of the sludge occurs and grinding is difficult. When the ratio of nepheline sludge and ash is 1: 1.1, the energy consumption for the initial grinding of nepheline sludge increases.

The ratio of nepheline sludge and ash: (2-3) in the second stage of grinding provides the final grinding of ash and nepheline Yosham while maintaining a uniform particle size distribution of the mixture,

 When a larger amount of ash is introduced into the raw material mixture, the strength of the products noticeably snoops, and when the ratio of nepheline sludge and ash is 1: 1.9, the structure is not sufficiently homogeneous.

The milling of the mixture in the first stage to a fraction of less than 200 µm is difficult due to the increase in the grinding time. Upon receipt of a fraction of more than 80 microns, in the final grinding, cellular material has low strength.

The difference between the proposed method and the known method is the pretreatment of the ash with fluoride hydride and the two-stage grinding of nepheline sludge together with the processed ash of Kans-Ko-Achinsk coal, leading to an increase in stability and uniformity.

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cellular structure, increase strength and reduce the bulk density of products.

Example. The manufacture of the raw material mixture is carried out on the basis of ash from incineration, Kansk-Achinsk coal, which has the following chemical composition, wt%: Si02 28-34; 6.8- 9.1; 13.9-15.8; CaO 30-35;

MgO 4.5-6.0; SOg 0.8-1.9; 0.8-1.6; ppp, 0.8-4.0; CaOce 6.5-10.2. Nepheline sludge has the following chemical composition, wt.%: SiO, 26.5-30.5; CaO 48.9-52.3; 2.9-3.6;

AljiOj 2.8-3.5; 1.9-2.8; p, p.p. 6.8-7.3.

Fluoride hydrite (hydrofluoric acid production waste) contains, wt%: CaO 26-34.2; SOj 56-63.5; 1016; HF 0.1-Oj15.

The ashes are premixed with: fluoride in 1: O ratio, f, and the grinding of nepheline sludge and ash is carried out in two stages; in the second stage to the resulting suspension

ash is added to a ratio of nepheline sludge and ash of 1: 2, and the mixture is finally ground to a fraction of less than 80 µm. The grinding is carried out at B / T 0.4. Calcium chloride is added to the mixture during final grinding. Then, the raw material mixture in the mixer with heating up to 30–40 s is mixed with an aqueous solution of aluminum powder and mice, the creeping mixture is poured into molds, into which the cellular material swells and cures for 6 hours,

Raw mixes are prepared similarly.

when the ratio of nepheline sludge and ash 1: 0.7; 1: 0.9; 1: 1; 1: 1.1 (in the first stage of grinding) and 1: 1.9; 1: 2.5; 1: 3.1 (in the second stage of grinding), the values of B / T for these mixtures are given in the table,

B. Raw mixture is added calcium chloride in the amount of 1, 5 May.7, (on a dry basis). Based on the raw mixtures obtained, the cellular concrete mixture is prepared in two ways: in the first case, the aluminum content313

powder is 0.15 wt.%, and in the second case, 0.12 wt.%. The samples obtained with further hydrothermal treatment (cubes with a 10 cm edge) are tested for compressive strength, bulk density, the coefficient of variation of the density is also determined, and the type of cellular structure (visually). The hydrothermal treatment is carried out according to the 3 + 8 + 3 h mode at. For comparison, the results obtained when testing cubes on the basis of raw mixtures obtained by a known method are used. The test results are shown in the table.

As can be seen from the table. 1, the application of the proposed method allows, in comparison with the known method, to increase the strength of products by 90%, to reduce the bulk density. The coefficient of variation in density by the proposed method is 3-4% versus 9-12% by the known method, while the obtained samples have a homogeneous cellular structure.

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Claims (1)

Formula of inventions A method of preparing a cellular concrete mixture, including grinding nepheline sludge in an aqueous solution of calcium chloride, mixing the resulting suspension with a solution of soap and aluminum powder, and pouring the mass into a mold, characterized in that and homogeneity of the porous structure, as well as increase in strength, with grinding, nepheline sludge is added to ashes, previously treated with fluoride in the ratio of ash: : fluoride hydride 1: 0.1-0.4, and grinding is carried out at В / Т 0.4-0.5 in two stages, and in the first stage, treated ash is introduced at an ash: nepheline ratio, slots 1: 0.8-1 and grind the mixture to obtain a fraction of 200 µm, and in the second stage, the treated ash is added to the treated sludge to a slurry: ash ratio of 1: 2-3 and the mixture is finally ground to a fraction of 80 µm in the presence of calcium chloride. go CTl N | Oi with about 1U1 CN -OCH Oh oh oh oh-j 00 Hc1 CVJ YU #t hch with sh about - W o 1L -it oh oh 1L about G: JО about 1L about o in oh oh oh oh oh 1ЛШШin oh oh oh oh 00 about year m about L “Go cho in in) "T VkM go fO - - 1- o about - Och- "" " - ate CV) in CN U1- m " go go f cho about in f, about oo about sh i about P about v about about sh h about in m about CN about sh with m about sh w about  1fls about in in " about sh go sh in in - in about