Regular-grade silicon

Regular grade silicon (99%) costs about 0.50/g. Silicon 99.9% pure costs about 50/lb hyperpure silicon may cost as much as 100/oz. 

Grade Ferrosilicon, regular (97% silicon), semiconductor or hyperpure (99.97% silicon), amorphous. 

The molten ferroalloy is regularly tapped by tilting the arc furnace and pouring it into ladles while the silicate slag is also tapped but on the other side and disposed of in landfill. The sili-cothermic process yields a low-carbon ferrochrome or LC ferrochrome (0.05 to 0.50 wt.% C) but with a silicon content of 8 to 12 wt.% Si. Further purification of ferrochrome can be performed by the Simplex process, which consists in reacting, in the solid state, high-carbon with oxidized ferrochromium to produce the extra-low-carbon grade (0.01 wt% C). 

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