The following editor will talk about the production process of soft composite silicon powder:

The soft composite silica powder is a glass-phase silica powder material made from natural quartz and other inorganic non-metallic minerals through compounding, melting, cooling, crushing, grinding, and classification.

Scope of application: Used for composite fillers such as CCL/EMC (for copper clad laminates), silicone, rubber, and plastics. Light diffuser for LED packaging, matting agent for paint, plastic modifiers such as PET, PMMA, PP, etc.

Common specifications: 3-4um, 4-5um (um is the unit of micron)

Main specifications: 3750-5000 mesh, 3000-3750 mesh (unit of mesh).

In the trichlorosilane method, the dry silicon powder is added to the synthesis furnace, and the dry hydrogen chloride gas is passed through the chlorination reaction in the presence of cuprous chloride catalyst at 280～330℃. The reaction gas is separated by cyclone to remove impurities, and then used Calcium chloride frozen brine condenses gaseous trichlorosilane into a liquid, distills and condenses in a crude distillation tower to remove high-boiling and low-boiling substances, and then distills and condenses in a rectification tower to obtain refined trichlorosilane liquid. The purity reaches more than 7 "9", the impurity content is less than 1×10-7, and the boron requirement is less than 0.5×10-9. The purified trichlorosilane is sent into a reduction furnace made of stainless steel, where ultra-pure hydrogen is used as a reducing agent, reduced to silicon at 1050-1100°C, and a silicon core rod is used as a carrier to deposit polycrystalline silicon products.

Mix silica with SiO2 content of about 95% and coke with less ash, and heat to about 1900°C for reduction. The silicon produced by this method has a purity of 97% to 98% and is called metallic silicon. Then the metal silicon is melted and recrystallized, and the impurities are removed with acid to obtain metal silicon with a purity of 99.7%-99.8%. If it is to be made into silicon for semiconductors, it must be converted into a liquid or gas form that is easy to purify, and then the polysilicon can be obtained through distillation and decomposition. To obtain high-purity silicon, further purification is required.

Mix silica with a SiO2 content of about 95% and coke with less ash, and use a 1000-3000kVA open arc furnace to heat to about 1900°C for reduction.

The above is the production process of soft composite silica powder briefly described by the editor. You can understand it briefly. The content is for reference only, please contact us if you need consultation.