Industrial silicon is classified into various grades according to its different applications. Based on the content of iron, aluminum, and calcium in quasi-metallic silicon, it can be divided into different grades such as 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501, and 1101. By-products of quasi-metallic silicon include microsilica powder, edge-skin silicon, black-skin silicon, and metallic silicon slag. Microsilica powder, also known as silica fume, is widely used in refractory materials and the concrete industry.
Main uses of industrial silicon
In the aluminum alloy industry, silicon-aluminum alloys are the most widely used silicon alloys. Silicon-aluminum alloys are strong composite deoxidizers; in the steelmaking process, they can replace pure aluminum, improving deoxidizer utilization and purifying molten steel, thus enhancing steel quality. The automotive and other industries have a significant demand for industrial silicon due to their use of aluminum; therefore, the development of the automotive industry in a region or country directly impacts the market for industrial silicon.
It is used as an additive for non-ferrous alloys, and industrial silicon is also used as an alloying agent for silicon steel with stringent requirements, and as a deoxidizer in the smelting of special steels and non-ferrous alloys.
In the chemical industry, silicone is used to produce organosilicon products such as silicone rubber, silicone resin, and silicone oil. Silicone rubber has good elasticity and high temperature resistance, and is used to make medical supplies and high-temperature gaskets. Silicone resin is used to produce insulating varnishes and high-temperature coatings. Silicone oil is an oily substance whose viscosity is minimally affected by temperature. It is used to produce high-grade lubricants, polishes, fluid springs, and dielectric liquids. It can also be processed into a colorless and transparent liquid for use as a high-grade waterproofing agent sprayed on building surfaces.
Industrial silicon is purified through a series of processes to produce polycrystalline silicon and monocrystalline silicon, which are used in the photovoltaic and electronics industries. Crystalline silicon cells are mainly used in rooftop solar power stations, commercial power stations, and urban power stations with high land costs. They are currently the most technologically mature and widely used solar photovoltaic products, accounting for more than 80% of the global photovoltaic market, and their demand for metallic silicon is growing rapidly. Modern large-scale integrated circuits are almost entirely made of high-purity quasi-metallic silicon, which is also the main raw material for producing optical fibers. It can be said that quasi-metallic silicon has become a fundamental pillar industry of the information age.
