Purification method of polysilicon by-product silicon tetrachloride

Abstract

The invention discloses a purification method of polysilicon by-product silicon tetrachloride. The purification method comprises the following step: adsorbing the polysilicon by-product silicon tetrachloride by amphoteric ion exchange resin to obtain purified silicon tetrachloride. In the purification method, the amphoteric ion exchange resin is adopted, so that the impurity content can be reduced, and the purity of polysilicon by-product silicon tetrachloride is improved effectively. Meanwhile, the amphoteric ion exchange resin can be used stably for a long time, so that the amount of resin used during long-term operation can be reduced, and the treatment cost of waste resin after use can be lowered. The purification method is simple, is low in energy consumption, is low in cost, and is conducive to the reuse of silicon tetrachloride.

Description

technical field [0001] The invention relates to the technical field of polysilicon production, in particular to a method for purifying silicon tetrachloride, a by-product of polysilicon. Background technique [0002] Polysilicon is an important basic material for electronic technology, information technology and photovoltaic power generation technology. The improved Siemens method has a long history, and the production process is relatively mature. This process uses trichlorosilicon as raw material, and uses silicon tetrachloride to reduce trichlorosilicon at high temperature to produce polysilicon. Using this method, it is easy to obtain higher yields. Polysilicon But the production of polysilicon by this method will produce a large amount of by-product silicon tetrachloride. Under normal circumstances, for every 1kg of polysilicon produced, 10-15kg of silicon tetrachloride will be discharged. Therefore, how to deal with the by-product silicon tetrachloride has become a ma...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two main ways to deal with silicon tetrachloride, a by-product of polysilicon: one is to make silicon tetrachloride, a by-product of polysilicon, into products such as ethyl silicate and organosilicon, but these methods have little effect on the digestion of silicon tetrachloride The amount is too small, and it often produces new environmental pollution while consuming waste; another way is to hydrogenate polysilicon by-product silicon tetrachloride into trichlorosilane, and return it to the synthesis process for reuse. The purity requirements for silicon tetrachloride are high, and the existing existing silicon tetrachloride purification methods have disadvantages such as large investment, high energy consumption, and complicated procedures.