| 摘要 |
<p>PROBLEM TO BE SOLVED: To highly maintain the purity of tetrachlorosilane or the like recovered by distillation, and further, to increase the recovery efficiency of tetrachlorosilane while smoothly removing metal chloride or the like.SOLUTION: Provided is a method for recovering tetrachlorosilane comprising: a recovery step where an exhaust gas from a reactor 5 precipitating polycrystal silicon is condensed and is subjected to gas-liquid separation, and the condensate is further distilled, thus a polymer is separated to recover tetrachlorosilane; and a chlorosilane refining step where the tetrachlorosilane is reacted with metal silicon and hydrogen so as to be converted into trichlorosilane, the conversion reaction gas thereafter is condensed, subsequently, the condensate is distillated with a refining distillation system 18, thus metal chloride is removed to refine the tetrachlorosilane. In the recovery step, the residue including the separated polymer is charged to the refining distillation system 18, and the polymer is exhausted together with the metal chloride.</p> |
