| As the photovoltaic industry material,polysilicon has been widely used.For Improved Siemens method of polysilicon production,the long process and low conversion rate of polysilicon reduction lead to high production cost of polysilicon.A certain amount of dichlorosilane(DCS)by-product is also produced in the process.The dichlorosilane processing technology is not very mature in the country,and ultimately leads to the enrichment of dichlorosilane.The safety and environmental issues are serious.In this paper,dichlorosilane is treated by anti-disproportionation process with LX-1121A resin catalyst.The operating conditions of the reaction device are optimized.The influence of reactor structure,filtration method and impurity in materials on the anti-disproportionation was studied.The conclusions are as follows:First,the elemental impurities content of silicon tetrachloride and silicon dioxide in the feed should be controlled at between 1~10?g/g,which can effectively extend the life of dichlorodihydride anti-disproportionation resin catalyst.The use cycle of resin can be maintained for more than a year.Second,in the feed range of 10m~3/h to 24m~3/h,the effects of molar ratio of silicon tetrachloride and dichlorosilane,reaction pressure and reaction temperature on the anti-disproportionation reaction were investigated.The optimized reaction conditions are as follows:when the total feed is 19~21m~3/h,the molar ratio of silicon tetrachloride and dichlorosilane is 4:1,the pressure is 200~300kPa,the temperature is controlled between 50-55?,the conversion of dichlorosilane is 2.6~2.7m~3/h,and the conversion rate can be maintained at 80%~90%,with high production efficiency.Finally,the parallel operation of multiple small-scale anti-disproportionation reactors is adopted to make the system run more stable.The final process can well meet the material balance,reduce energy consumption and production costs which lay the foundation for the continued development of enterprises. |
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