METHOD OF CARBO-THERMAL REDUCTION OF SILICON Russian patent published in 2010 - IPC C01B33/25 

FIELD: metallurgy.

SUBSTANCE: method of silicon reduction out of its oxides consists in preliminary preparation of briquettes containing silica and carbon containing reducer, in supplying charge into ore-thermal furnace, where charge contains briquettes and not briquetted silica, and in successive two-stage charge heating. Contents of silicon dioxide and carbon in briquettes are maintained in stoichiometric ratio in terms of reaction of production of silicon carbide, while contents of not briquetted silica in charge to silicon in a briquette are maintained at ratio 1:2. As a carbon containing reducer there are used reducers with contents of hydrogen not less, than 5% of total mass of the reducer.

EFFECT: increased degree of silicon extraction at reduced consumption of raw materials and power.

2 tbl, 5 ex