POLYCRYSTALLINE SILICON MANUFACTURING METHOD

摘要

The disclosed polycrystalline silicon manufacturing method comprises: a silicon tetrachloride manufacturing step for obtaining low-purity silicon tetrachloride; a silicon tetrachloride distillation step; a polycrystalline silicon manufacturing step for obtaining polycrystalline silicon; a first separation step for separating the components in exhaust gas into a mixture of zinc chloride and un-reacted zinc, and un-reacted silicon tetrachloride; and an electrolysis step for obtaining zinc and chlorine gas by electrolysing the mixture of zinc chloride and un-reacted zinc. The method is characterised in that: the un-reacted silicon tetrachloride obtained in the first separation step is transferred to the silicon tetrachloride distillation step and distilled together with the low-purity silicon tetrachloride; the chlorine gas obtained in the electrolysis step is used as the chlorine gas for reacting in the silicon tetrachloride manufacturing step; and the zinc obtained in the electrolysis step is used as the zinc for reacting in the polycrystalline silicon manufacturing step. Thus, the disclosed polycrystalline silicon manufacturing method has low manufacturing costs, and involves simple operational and device management.