What is the raw material of silicon metal production?

The raw materials of smelting industrial silicon mainly include silica and carbonaceous reducing agent.Due to the strict restrictions on the content of aluminum, calcium and iron in industrial silicon, the requirements for raw materials are particularly strict.Silica in the SiO2 & gt;99.0% of Al2O3 & lt;0.3%, Fe2O3 & lt;0.15%, CaO<0.2%, MgO<0.15%;The particle size is 15~80mm.The principle of choosing carbonaceous reducing agent is: high fixed carbon, low ash content, good chemical activity.Usually petroleum coke or asphalt coke with low ash content is used as reducing agent.However, due to the two kinds of coke resistivity is small, poor reaction ability, so must be matched with low ash, high resistivity and strong reaction ability of charcoal (or wood) instead of part of the petroleum coke.In order to make the charge sintered, some low ash bituminous coal should be added.Must point out, overmuch or all use charcoal, not only can raise product cost, and still can make furnace condition disorder, if because of material surface sintering is poor and cause prick fire to collapse material, form high temperature reaction area, bottom of furnace is easy to open into SiC layer, give iron difficulty etc.