SU53699A1 - Method of smelting ferrosilicon in electric furnaces - Google Patents

Description

In smelting ferrosilicon in electric furnaces, a charge consisting of quartz, iron ore or iron shavings and coke is used.

The present invention proposes to smelt ferrosilicon in electric furnaces, not from ordinary sludge, but from sinter and coke.

A characteristic feature of the agglomerate is that it is prepared from river or quartz sand and fine or dusty iron ore, or from a mixture of sand with small pieces of quartz (or quartzite) with a particle size of up to 30-40 mm and iron ore, or from small pieces of quartz and iron ore.

Of course, a certain amount of fuel in the form of coke, anthracite, etc. is introduced into the binder intended for agglomeration. After sintering, a porous agglomerate is obtained in which the iron oxides are evenly distributed among the silica. The smelting of ferrosilicon from such agglomerate (mixed with a reducing agent) significantly increases the productivity of the furnace, reduces the unit cost of electricity (in an ultrastrope furnace), and reduces the cost of ferrosilicon. This is explained by the following: 1) first of all, iron oxides

in the furnace, they are reduced to metallic iron, which appears to be very evenly distributed. in charge and with a large surface; 2) the presence in the mixture of uniformly distributed metallic iron significantly reduces the temperature of silicon reduction;

3) the reduced silicon is almost completely evaporated, since, at the time of the reduction, it dissolves in the vicinity of the iron particles;

4) due to the large surface and porosity of the agglomerate, the charge is well gas-permeable, and the gases leave the furnace relatively cold, having managed to give the charge a significant part of the physical heat.

In addition, the use of agglomerate causes:

a) a significant decrease in gas pressure in the lower part of the electric furnace, thus eliminating the possibility of charge emissions and the appearance of fistulas;

b) a faster discharge of the charge due to the large porosity and low volumetric weight of the sinter; and

c) a significant reduction in the cost of raw materials per unit of ferrosilicon, as the cost of sinter made from sand or waste.

quartz and silt ore, significantly lower than the cost of quartz and iron chips.

The ratio between the amounts of silica and iron oxides in the agglomerate is different and the higher, the higher the silicon content must be obtained in the alloy.

In addition to the sinter and the reducing agent, there may be a certain amount of metallic iron (in the form of chips, scraps, etc.) and quartz (or quartzite) in the charge.

Experiments conducted in a small electric oven showed that

the use of sinter significantly reduces the specific energy consumption, improves productivity and allows you to operate at a higher voltage compared to working in a conventional charge.

The subject matter of the invention.

A method of smelting ferrosilicon in electric furnaces, characterized in that an agglomerate obtained by sintering silt or fine iron ore with sand or small pieces of quartz materials is introduced into the mixture.