To provide a method for continuously refining polycrystalline silicon by which, when the polycrystalline silicon is produced by reducing silicon tetrachloride by a zinc reduction method, reduction is continuously performed and generation of un-reacted silicon tetrachloride and zinc are suppressed to heighten generation efficiency of the polycrystalline silicon and un-reacted zinc and silicon tetrachloride and zinc chloride to be a reaction by-product are efficiently recovered and reused.
The method for continuously refining the polycrystalline silicon by the zinc reduction method includes a step of reducing refined silicon tetrachloride by continuously bringing refined silicon tetrachloride and zinc into contact with each other to continuously produce highly refined polycrystalline silicon and zinc chloride, a wet reaction step of adding water to the produced zinc chloride to produce a zinc chloride aqueous solution having regulated zinc concentration, an electrolysis step of electrolyzing the zinc chloride aqueous solution and separating zinc and chlorine, a step of recovering un-reacted refined silicon tetrachloride and zinc in the step and a step of recycling zinc, chlorine and silicon tetrachloride recovered by the step.
MAEBA KAZUYA
TAN TOSHIRO
ISHIDA HITOSHI
