Silicon metal, also known as crystalline silicon or industrial silicon, is mainly used as an additive for non-iron based alloys. Silicon metal is a product smelted by quartz and coke in the electric heating furnace. The content of main component silicon element is about 98% (in recent years, 99.99% Si content is also included in silicon metal), and the remaining impurities are iron, aluminum, calcium and so on. According to the content of iron, aluminum and calcium in silicon metal, silicon metal can be divided into 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501, 1101 and other different grades.