High-purity Polysilicon

ZhenAn International Co., Limited is one of the most reliable manufacturers and suppliers of high-purity polysilicon in China. With abundant experience, we warmly welcome you to wholesale discount high-purity polysilicon in stock here from our factory. Quality products and reasonable price are available.

High-purity polysilicon is the basic raw material for the electronics industry and solar photovoltaic industry. It is an extremely important intermediate product in the silicon product industry chain and has a profound impact on the development of my country's national economy. , technical problems, and industrialization gaps seriously restrict the development of this industry in China .

At present, my country's polysilicon industry has a certain advantage in the world, and the problem of pollution has been repeatedly put on the agenda. With the gradual improvement of the production process17, the pollutants have gradually shifted from silicon tetrachloride to silicon slag. In particular, the recent development of cold hydrogenation has fully utilized silicon tetrachloride3, and the problem of treatment has immediately turned to the fluidity of solid-liquid mixed silicon slag.

In the past period of time, a large amount of this silicon slag was disposed of by simply burying it or even dumping it directly. The consequences of this directly caused serious environmental pollution accidents, the land was barren and the water source was severely damaged. Due to the relatively late start of domestic polysilicon, most of the treatment methods for silicon slag are based on the treatment methods of silicon slag in the organic silicon industry. Compared with polysilicon, the production process of organosilicon is relatively mature in China, so the research on its subsequent treatment is relatively perfect. Part of the silicone slurry treatment process in the production of organic silicon, especially the hydrolysis method, has become a reference object for polysilicon manufacturers.

Main treatment methods of domestic silicon slag slurry The main components of silicon slag slurry discharged from trichlorosilane synthesis and cold hydrogenation reaction are: Si.SiCl.SiHCl.SiH, Cl, polychlorosilane, AlCl and B, P elemental Its compounds (mainly oxides), etc. Among them, silicon and chlorosilanes account for the majority. At present, domestic silicon slag is mainly treated by alkali hydrolysis and drying! , and recently someone has proposed an extraction method to treat silicon slag 

 Hydrolysis The hydrolysis method is to press out the liquid part of the waste residue slurry, heat and vaporize it, send it to the tail gas scrubber, wash it with hydrochloric acid solution, and finally neutralize the acid waste liquid with lye.
The hydrolysis method can realize the final harmless treatment of waste liquid, but it still cannot deal with the residual high-concentration silicon slag slurry, and can only reduce it. Moreover, the water consumption and alkali consumption of the hydrolysis process are quite large, which greatly increases the operating cost.

The drying method is mainly to use the dryer to heat, pump the silicon slag with a solid slag content of 20% into the drying equipment and stir, and evaporate the chlorosilane vapor through heating with saturated water vapor, and recover part of the chlorosilane.
After drying, the solid slag content of polysilicon can reach 80%, further greatly reducing the capacity. The danger of solid slag after treatment is also greatly reduced, but there is no suitable and feasible way for final solid slag treatment. 

Extraction The basic idea of the extraction method originated from the treatment of organic silicon waste residue in US4221691. By adding alkane oil into the waste silicon slag slurry, fully mixing with the slurry, drying and separating by rectification, recovering chlorosilane, recycling the alkane oil, and finally removing the oil residue with a very small fluorosilane content (the main component is silicon slag and alkane oil) are discharged for separate treatment. The extractant alkane oil in the extraction method also acts as a lubricant while being used as an extractant.

It overcomes the problem of cold blocking of pipelines and equipment in the process of direct hydrolysis treatment, and eliminates the problem of a large amount of acidic sewage produced by hydrolysis. Moreover, the useful component chlorosilane in the silicon slag slurry is fully extracted, turning waste into treasure, and bringing great economic benefits.

The extraction method also has no good way to deal with the final oil residue, but compared with the above two methods, it solves the chlorosilane in the silicon slurry and reduces the burden of subsequent treatment. However, the extraction method has not been well implemented at present, and the problems caused by it in the actual processing process are currently immeasurable. The actual effect of the extraction method has yet to be reflected in the actual processing process. We will wait and see.

Q: If I need customized packaging, is that available?
A: Yes, we can supply different specifications of bag or steel drum according to you requirement.

Q：What are the payment terms?
A：Usually T/T ， or L/C.

Q : What is your lead time?
A : It usually needs about 15- 20 days after receiving the PO.

ZHENAN INTERNATIOANL CO., LTD

Fax: +86-372-5055180

Email: kevin@zaferroalloy.com

Website: www.zaferroalloy.cn

Address: 1-2510,Huafu Office Building,Anyang,Henan,China.

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