RU2381199C1 - Raw mix and method for manufacturing of ceramic products - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention is related to production of wall ceramic products and may be used to manufacture construction materials. Raw mix for manufacturing of wall ceramic products includes microsilica from production of crystalline silicon, dust from electric filters from production of aluminium and flue ash from combustion of brown coals from Irsha-Borodinskoe deposit, at the following ratio of components in wt %: microsilica - 79-82; dust of electric filters from production of aluminium production - 15; flue ash - 3 -6. Method for production of wall ceramic products from raw mix includes preparation of charge, moulding, drying, annealing at the temperature of 750°C, and after annealing, products are soaked in water for 48 hours.

EFFECT: increased compressive strength after moistening, coefficient of structural quality and frost resistance, reduced temperature of products annealing.

2 ex, 2 tbl

Description

The present invention relates to the production of wall ceramic products and can be used for the manufacture of 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 crystalline 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, C04B 35/16).

The disadvantages of this mixture are the relatively low values of compressive strength after steaming, the coefficient of structural quality, frost resistance, as well as increased firing temperature and fuel consumption.

The technical result is an increase in compressive strength after wetting, a coefficient of structural quality and frost resistance, a decrease in firing temperature and fuel consumption.

The specified technical result is achieved in that the raw material mixture for the manufacture of wall ceramic products contains microsilica of crystalline silicon production, dust of electrostatic precipitators of aluminum production and fly ash from burning brown coal of the Irsha-Borodinsky deposit in the following ratio of components (in wt.%):

Silica fume 79 ... 82 Dust of aluminum electrostatic precipitators fifteen Fly ash 3 ... 6

Silica fume production of crystalline silicon is a dispersed waste of the Bratsk aluminum plant, characterized by a small particle size (0.1 ... 3 μm) and, as a result, a high specific surface (25 ... 34 m ² / g) and a low bulk density (up to 0.3 g / cm ³ ). The chemical composition of silica fume production of crystalline silicon (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 C _total up to 9 K ⁺ up to 0.25 Na ⁺ up to 0.06 P.p.p. up to 20

The dust of electrostatic precipitators of the main production of aluminum is a dispersed waste from the production of aluminum 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 (wt.%):

F up to 10.54. Al ₂ O ₃ up to 26.4 Na ₂ O up to 8.96 CaO up to 1.68 MgO up to 0.88 Fe ₂ O ₃ up to 0.88 SiO ₂ up to 2.0 P.p. up to 43.36

Fly ash is a waste from thermal power plants generated by burning brown coal from the Irsha-Borodinsky deposit. Fly ash contains (wt.%):

Cao up to 20.0 ... 35.0 MgO up to 3.0 ... 6.0 SiO ₂ up to 40.0 ... 55.0 Fe ₂ O ₃ up to 6.0 ... 14.0 Al ₂ O ₃ up to 4.0 ... 10.0 K ₂ O up to 0.3 ... 1.5 Na ₂ O up to 0.2 ... 0.5 SO ₃ up to 0.9 ... 5.0 P.p.p. no more than 2

A known method of manufacturing ceramic products, including the preparation of a mixture, molding, drying and firing at 800 ° C (RF patent No. 2254309, C04B 35/14). The disadvantage of this method is the increased cost of firing and low strength of fired products, the coefficient of structural quality and frost resistance.

The technical result is achieved by the fact that the method of manufacturing wall ceramic products includes preparing the mixture, molding, drying, firing at 750 ° C and additionally keeping it in water after firing for 48 hours.

Example 1. To prepare the raw material mixture, microsilica is used to produce crystalline silicon from the Bratsk aluminum plant, dust from electrostatic precipitators of the main aluminum production from the Bratsk aluminum plant, and fly ash from burning brown coal from the Irsha-Borodinsky deposit.

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%. Samples of cylinders with a diameter of 40 mm are formed from the obtained raw material mixture by the method of semi-dry pressing at a specific pressing pressure of 20 MPa.

Then the semi-finished product is dried at room temperature to constant weight and calcined at a temperature of 750 ° C.

Example 2. Products made according to claim 1, after firing, incubated in water for 48 hours.

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 79.0 80.5 82.0 Dust of electrostatic precipitators fifteen fifteen fifteen Fly ash 3.0 4,5 6.0

table 2 Indicator Compositions Prototype one 2 3 Firing temperature, ° C 750 750 750 800 The average density, kg / m ³ 1163 1187 1210 1226 ... 1245 Compressive strength after wetting, MPa 33.70 35.41 36.12 - Compressive strength after steaming, MPa - - - 28.5 ... 31.3 Water absorption, wt.% 36,42 35.50 34.57 34 ... 37 The coefficient of structural quality × 10 ² , MPa / (kg / m ³ ) 2,898 2,983 2,985 1.7 ... 1.9 Frost resistance cycles fifty fifty fifty 35 Note: 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 calcined products .

Claims (2)

1. The raw material mixture for the manufacture of wall ceramic products, including microsilica of crystalline silicon production, dust of electrostatic precipitators of aluminum production and fly ash from burning brown coal of the Irsha-Borodinsky deposit, characterized in that it contains components in the following ratio, wt.%:
Silica fume 79-82 Dust of aluminum electrostatic precipitators fifteen Fly ash 3-6 2. A method of manufacturing wall ceramic products from a raw mix according to claim 1, including the preparation of a charge, molding, drying, firing and further processing, characterized in that the products are fired at 750 ° C and after firing, they are kept in water for 48 hours.