Raw Materials For Industrial Silicon Smelting

The raw materials for smelting industrial silicon are mainly silica and carbonaceous reducing agents. Due to the strict restrictions on the content of aluminum, calcium and iron in industrial silicon, the requirements for raw materials are also very strict. In silica, SiO2>99.0%, Al2O3<0.3%, Fe2O3<0.15%, CaO<0.2%, MgO<0.15%; the particle size is 15-80mm. The principle of selecting carbonaceous reducing agent is: high fixed carbon, low ash content and good chemical activity. Usually, low ash petroleum coke or pitch coke is used as the reducing agent. However, due to the low resistivity and poor reaction ability of these two kinds of coke, it is necessary to replace part of the petroleum coke with charcoal (or wood block) with low ash content, high resistivity and strong reaction ability. In order to sinter the charge, some low-ash bituminous coal should also be added. It must be pointed out that using too much or all charcoal will not only increase the cost of the product, but also make the furnace condition disorder. , Difficulty in tapping, etc.