PROCESS FOR PRODUCING HIGH-PURITY METALLIC CALCIUM, PROCESS FOR PRODUCING METALLIC TITANIUM WITH USE OF THE CALCIUM, AND HIGH-PURITY METALLIC CALCIUM PRODUCING APPARATUS

摘要

A process and apparatus for production of metallic calcium for use in the production of metallic titanium through reduction of a titanium compound; especially a process and apparatus for efficient production of high-purity metallic calcium from the metallic calcium produced by molten salt electrolysis. There is disclosed a process for producing a high-purity metallic calcium, characterized by including the step of performing a molten salt electrolysis of the calcium chloride produced as a by-product in the operation of titanium compound reduction by metallic calcium to thereby obtain metallic calcium and, thereafter but prior to the step of producing metallic titanium with the use of the metallic calcium produced by the molten salt electrolysis, the step of separation and purification of metallic calcium, wherein in the step of separation and purification, a solid precipitate consisting of the electrolytic bath and the metallic calcium precipitated on the negative electrode by the molten salt electrolysis is melted in a melting separation vessel to thereby obtain a state of two-phase separation consisting of molten metallic calcium and electrolytic bath and wherein while retaining the state of two-phase separation, only the metallic calcium is caused to overflow into a purification vessel.