Progress in Japan’s Titanium Metal Preparation Technologies

The progresses of Japan’s titanium metal preparation technologies in recent years,such as preparation of titanium sponge,new titanium metal extraction technologies,titanium scrap recovery and purification,were summarized in this paper. The technical progresses in adjustment of raw materials structure,enhancement of single furnace production capacity,purity improvement of raw material （TiCl₄ and Mg） and quality amelioration of titanium sponge,made by Osaka Titanium Technologies Co.,Ltd.and Toho Titanium Industry Co.,Ltd.in preparation of titanium sponge,were emphatically introduced.The use ratio of titanium material containing 90%~92% TiO₂ is more than 30%.Titanium sponge production capacity of single furnace has reached to 13 tons.The stable production and preparation process of high purity titanium has been established by Kroll process and the purity of titanium metal is 99.999% （5N9）.Alternative titanium metal extraction technologies to lower the production costs,which include OS （calcium thermic reduction）process,electronically mediated reaction and molten salt electrolysis （EMR/MSE process）,preformed reduction process （PRP process）,and their technical characteristics were discussed. Recovery of titanium metal scrap for TiCl₄ preparation and direct oxygen removal technique utilizing MgCl₂ molten salt electrolysis of titanium metal scrap were also reviewed.The technology feasibility of new methods was proved by theories and experiments,but further studies,such as simplifying the equipment,improving production efficiency and product purity,still need to be conducted for replacing the Kroll process.