Burning treatment process of waste gas and waste liquid containing chlorosilane in polysilicon production

Abstract

The invention relates to a burning treatment process of waste gas and waste liquid containing chlorosilane in polysilicon production, which comprises the steps of: removing waste gas and waste liquid containing chlorosilane (trichlorosilane, dichloro-dihydro-silicon, silicon tetrachloride and metal chloride) in the production process of polysilicon; using natural gas as fuel in a burning furnace; and hydrolyzing the chlorosilane in the waste gas and the waste liquid at high temperature under the conditions of high temperature of 900 DEG C to 1000 DEG C and pressure of 0.01 to 0.06 barg to generate SiO2, HCl, a small quantity of Cl2 and the like which can be easily processed. In the process, the toxic chlorosilane difficult to process is burned and hydrolyzed at high temperature to generate SiO2, HCl, a small quantity of Cl2 and the like which can be easily processed; therefore, the problems of incomplete performance of absorption of alkaline hydrolysis and neutralization and sedimentation treatment of Ca(OH)2, difficult removal of chlorine ions, serious secondary pollution, generation of a large quantity of waste water and waste dregs, high operating cost and the like are solved. Simultaneously, the waste water and the waste dregs are not generated basically and useful resources are recycled.

Description

1. Technical field [0001] The invention relates to a combustion treatment process of chlorosilane waste gas and waste liquid in polysilicon production, which belongs to the combustion treatment process of chlorosilane waste gas and waste liquid discharged during polysilicon production. This process is to discharge waste gas and liquid containing chlorosilane (trichlorosilane, dichlorodihydrosilane, silicon tetrachloride and metal chloride) from the production process of polysilicon, and use natural gas and combustion-supporting air in the combustion furnace. Through the high-temperature hydrolysis reaction, easy-to-handle materials such as SiO2, HCl and a small amount of Cl2 are generated. 2. Background technology [0002] With the rapid development of the polysilicon industry and the continuous expansion of scale and output, the safety and environmental protection problems of chlorosilane waste gas and waste liquid discharged during the polysilicon production process have b...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a combustion treatment process for chlorosilane waste gas and waste liquid in polycrystalline silicon production, which is to discharge chlorosilane (trichlorosilane, dichlorodihydrosilane, silicon tetrachloride and Metal chloride) waste gas and waste liquid, in the combustion furnace, use natural gas and combustion-supporting air, through high-temperature hydrolysis reaction, to generate easy-to-handle SiO2, HCl and a small amount of Cl2 and other substances, which can overcome the hydrolysis alkali absorption and lime milk Ca ( Oh) 2 Incomplete neutralization and precipitation treatment, no way to remove chloride ions, serious secondary pollution, large amounts of waste water, waste residue, high operating costs, etc.

Images