Very higher purity silicon for semiconductors is acquired using the Siemens approach; the silicon is reacted to make trichlorosilane, which happens to be initial purified by distillation, then reacted with purified hydrogen on large purity silicon rods at 1150 oC to produce large purity, polycrystalline silicon with hydrochloric acid byproduct. https://glass-lined-ductile-iron25702.wikiusnews.com/1664773/indicators_on_carborundum_silicon_carbide_you_should_know