RU2323913C1 - Feedstock mix for wall products generating - Google Patents

Abstract

FIELD: building.

SUBSTANCE: feedstock mix for wall products generating contains microsilica and the dust of electro-filters of producing the aluminium with the following ratio mass %: microsilica - 85-81; the dust of electro-filters - 15-19.

EFFECT: diminution of middle density and thermal conductivity and it is increased the coefficient of construction quality.

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Description

The present invention relates to the production of wall products and can be used for building materials.

Closest to the proposed raw mix in technical essence and the achieved effect is a raw mix, including (in wt.%): Silica fume production of metallic silicon 52.7-56.3; fly ash 42.5-46.5; dust of electric filters of aluminum production 0.8-1.2 (RF patent No. 2254309 С04В 35/16).

The disadvantages of this mixture are relatively high values of density and thermal conductivity and slightly low values of the coefficient of structural quality.

The raw mix refers to compositions for the manufacture of wall products.

The technical result is a decrease in density and thermal conductivity and an increase in the coefficient of structural quality.

The specified technical result is achieved in that the raw material mixture for the manufacture of wall products contains silica fume and dust from electrostatic precipitators of aluminum production as raw materials in the following ratio of components (in wt.%):

Silica fume 85-81 Dust of aluminum electrostatic precipitators 15-19

Silica fume is a fine waste of the Bratsk Aluminum Plant, characterized by a small particle size (0.1-3 microns) and, as a result, a high specific surface (more than 25000 cm ² / g) and a small bulk density (up to 0.3 g / cm ³ ). Silica fume is deposited in electrostatic precipitators of gas treatment systems of melting furnaces for the production of crystalline silicon, after which it is removed as an aqueous suspension in a sludge storage facility. The chemical composition of silica fume (in wt.%):

SiO ₂ 90-95 Al ₂ O ₃ up to 0.8 Fe ₂ O ₃ up to 0.8 CaO up to 1.6 MgO up to 1.2 SiC up to 5 With _total up to 9 K ⁺ up to 0.25 Na ⁺ up to 0.06 P.p.p. up to 20

Dust of aluminum electrostatic precipitators is a large-tonnage dispersed waste of aluminum production with an average particle size of 5-8 microns and a bulk density of 0.84-0.92 g / cm ³ . The dust of electrostatic precipitators of the Bratsk aluminum plant contains (in wt.%):

F 10.54 Al ₂ O ₃ 26,4 Na ₂ O 8.96 Cao 1.68 MgO 0.8 Fe ₂ O ₃ 0.88 SiO ₂ 2.0 P.p.p. 43.36

The technological advantage of silica fume and dust from aluminum electrostatic precipitators is the absence of the need for preliminary preparation (grinding), as well as the combination of mineralizing and organic components in the additive composition.

Example. To prepare the raw mix, silica fume produced by crystalline silicon of the Bratsk aluminum plant and dust from electrostatic precipitators of the Bratsk aluminum plant are used.

The process of preparing the mixture includes the following operations: dry components are thoroughly mixed, then moistened with water to a moisture content of 23%. Products are formed from the raw mix by the method of semi-dry pressing (25 MPa).

Then the semi-finished product is dried at room temperature to constant weight and calcined at a temperature of 700 ° C.

Examples of compositions and physico-mechanical properties of products based on them are given in tables 1 and 2.

Table 1 Components The content of ingredients in the composition, wt.% one 2 3 Silica fume production of crystalline silicon 85 83 81 Dust of aluminum electrostatic precipitators fifteen 17 19 table 2 Indicator Compositions Prototype one 2 3 Firing temperature, ° С 700 700 700 800 The average density, g / cm 1.11 1.13 1.15 1.226-1.245 Compressive strength, MPa 27.8 27.3 27.0 28.5-31.3 Water absorption, wt.% 41.3 40.0 38.7 34-37 KKK, MPa / (kg / m ³ ) LO ' ² 2.5 2.42 2.35 1.7-1.9 Thermal conductivity 0.46 0.47 0.48 0.524-0.534

Note: KKK - the coefficient of structural quality is calculated as the ratio of compressive strength (MPa) to average density (kg / m ³ ), and the softening coefficient is calculated as the ratio of the strength of wet samples (after being in water for 2 days) to the strength of dry burnt products.

Thermal conductivity calculated by the formula

Claims (1)

The raw material mixture for the manufacture of wall materials, including as a main component silica fume and as an additive, dust from electrostatic precipitators of aluminum production, characterized in that it contains components in the following ratio of components, wt.%: silica fume  85-81 aluminum electrostatic dust  15-19