SU1535825A1 - Method of obtaining silicon - Google Patents

Abstract

The invention relates to methods for producing silicon and its alloys, and it makes it possible to reduce the cost of production while maintaining its purity in terms of iron. Mix quartzite with wood chips and add briquetted gas cleaning dust of the fraction - 8 + 0.04 mm in the amount of 14.5 - 32 wt.% Of the mass of the charge, and before briquetting the dust, the fraction -4 + 0.04 mm is extracted, subjected to the magnetic separation and the non-magnetic component are combined with the remaining dust. 6 tab.

Description

This invention relates to methods for producing silicon and its alloys.

The purpose of the invention is to reduce the cost of the product while maintaining its purity in terms of iron.

Primer p. In the production of I t of silicon, 225 kg of dust fraction -8 + 0.04 mm is formed, which contains 0.8 wt.% Ge, 03 or 1.26 kg Fe. Selected from this dust by screening, the -4 + 0.0 mm fraction is 153 kg and already contains 1.1% by weight of Pe203. From this fraction, as a result of separation in the electromagnetic separator SE-3, a magnetic fraction was separated, which amounted to 3 wt.% Or 4.59 kg. It contains 17% by weight of FejO or 0.564 kg of Fe and 2% by weight of Fe3C or 0.0856 kg of Fe. After removing the magnetic component and combining the purified dust with a fraction of 8.0 to 4.0 mm, the amount of iron in the crucible dust was: 1.26 - (0.564 +

+ 0.085b) 0.615 kg, equivalent to 0.878 kg., Or 0.39% by weight of Fee05.

The iron-cleared dust is precoated and sent to the dosing compartment, where the components of the mixture are weighed. The content of briquetted dust in the charge is 32 wt.%.

The composition of the charge with the maximum use of dust and its effect on containing Fe impurities are given in Table 1.

The mixed charge is sent to the ore-thermal furnace furnace, from where it is fed to the furnace top. In the ore-smelting furnace, silicon dioxide is reduced by carbon contained in briquetted dust and wood chips, at a temperature in the first stage of 1700-1850PC and in the second at 2000-2200 ° C. The process is conducted continuously, the resulting silicon

with

SP

00

Yu

Sl

yut through the tap hole and after solidification are crushed.

The dependence of the quality of silicon, energy consumption and furnace productivity on the amount of coarse dust introduced in the form of briquettes is presented in Table 2.

The main indicators of the smelting of silicon with additives to the charge, purified from iron of coarse dust in the form of briquettes in the amount of 14, 21 and 32 wt.1, are given in table 3.

The chemical and granulometric compositions of the original dust, as well as the chemical composition of the fraction subjected to magnetic separation, are presented in Tables A, 5 and 6.

Thus, the proposed method allows to reduce the cost of the product for

five

0

by reducing the specific consumption of quartzite, carbon-containing reducing agents and electricity while maintaining the grade of fused silicon.

Claims (1)

Invention Formula A method of producing silicon, which includes mixing quartzite, a carbon-containing reducing agent, and a briquetted gas cleaning dust fraction -8 + 0.04 mm, reduction smelting in a ore-smelting furnace, characterized in that dust in the amount of 14 wt.% g, and before briquetting a fraction of 4 + 0.04 mm is separated from it, subjected to magnetic separation and the non-magnetic component is combined with the remaining dust. Table 1 Briquette Dust32 Quartzite36 Wood chips 32 including: petroleum coke charcoal coals wood chips Coarse dust gas cleaning brie 0.382 0.225 The content of Fe impurity introduced by the tool during processing is 0.2 wt.%. In total, when melting the standard charge, the Fe content in silicon is 0.807 wt.% Table 32 3 3 8 33 The chemical composition of dust, gas cleaning ETC Content, wt.% 79.8 0.5 0.7 Tab ita5 Particle size distribution of dust, entering the gas cleaning system ETC NriAZl The content of the fraction, mA. T 53 Continuation of table 2 Table3 Table4 entering the IrkAZ system 1.7 0.50.20.4 4.6 11.6 ten ten 715358258 Tablat Chemical composition of dust fraction -4 + 0j04 mm Components I CaOMgO NaeOK «0 Csobry. SiC Content wt.% 34.9 0.5 1.1 1.9 0.6 0.3 0.4 26.0 34.3