METHOD OF PURIFYING TECHNICAL SILICON Russian patent published in 2018 - IPC C01B33/37 B22D1/00 C22B9/05 C22B9/10 

FIELD: metallurgy.

SUBSTANCE: invention relates to non-ferrous metallurgy and can be used to purify technical silicon obtained by reduction melting in ore-thermal electric furnaces. Method involves purging the silicon melt with compressed air through a porous part of the bottom of the ladle during the pouring process from the furnace to the ladle with continuous and uniform flux feeding to the surface of the melt. After filling the ladle, the silicon melt is separated from the slag, poured into a prepared new ladle, and the melt is blown with compressed air in a new ladle, while simultaneously loading silica onto the silicon surface, consisting of quartz sand, limestone and alumina, with the following ratio of components, %: quartz sand 50–55; limestone 35–40; alumina 10–12.

EFFECT: increasing quality of technical silicon by reducing the calcium content in silicon to less than 0,005 % by weight.

1 cl, 7 ex