Differences between ferrosilicon and polycrystalline silicon
-Ferrosilicon:
Ferrosilicon is an iron alloy composed of iron and silicon. It is an essential deoxidizer in the steelmaking industry. During the steel making process, ferrosilicon is used for precipitation deoxidation and diffusion deoxidation. Adding a certain amount of silicon to the steel not only can significantly increase the strength, hardness and elasticity of the steel, but also improve the magnetic permeability of the steel and reduce the hysteresis loss of the transformer steel. Normally, the steel contains 0.15%-0.35% silicon, the structural steel is composed of 0.40%~1.75% silicon, the tool steel contains 0.30%~1.80% silicon.
High purity ferrosilicon can be used as reducing agents in the production of low-carbon iron alloys. We can add the ferrosilicon as the inoculant for the process of cast iron. It can prevent the formation of carbides, promote the precipitation and spheroidization of graphite and improve the properties of cast iron.
Additionally, the ferrosilicon powder can be used as the suspension phase in the beneficiation industry and the coating for welding rods in electrode manufacturing. The high purity ferrosilicon can be used to prepare pure semiconductor silicon in the electrical industry. In the steelmaking industry, each ton of steel produced consumes approximately 3 to 5 kg of 75% ferrosilicon.
-Polycrystalline silicon:
Nature: gray metallic luster. The density is 2.32~2.34. The melting point is 1410°C. The boiling point is 2355°C. It is soluble in the mixed acid of hydrofluoric acid and nitric acid. On the other hand , it is insoluble in water, nitric acid and hydrochloric acid. The hardness of polycrystalline silicon is between germanium and quartz. It is brittle under indoor temperature and easy to break when cutting. The polycrystalline silicon is ductile when heated to above 800℃. It is deformed obviously at 1300℃.
The polycrystalline silicon is inactive under normal temperature and reacts with oxygen, nitrogen, sulfur under under high temperature. It has greater chemical activity and can interact with almost any material under the high temperature molten state. It also has semiconductor properties and is an extremely important and excellent semiconductor material, The polycrystalline silicon is an important and high practicability semiconductor material. It is widely used in the manufacture of basic materials for semiconductor radios, tape recorders, refrigerators, color TVs and video recorders.
