Mikkaichi Smelter, Nippon Mining Co., Ltd., operating since 1954, is at present the only zinc smelter in the world that employs the resistance electrothermic zinc distillation process, which was originally developed bySt . Joe Minerals Corp., U.S.A.. Zinc concentrates are first roasted at Tsuruga Plant to produce zinc calcine and sulfuric acid . Zinc calcine is then transported to Mikkaichi Smelter to be sintered, distilled and refined. Products are Prime Western zinc metal , Special High Grade

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... zinc metal, Tailored zinc metal, diecast alloys and cadmium metal. The resistance electrothermic zinc distillation is a distinctive process that has the following unique features: 1) The process uses both coke and electricity as the sources of energy. Although energy consumption per unit of produced zinc metal is higher than those in other smelting processes, eventual energy cost is similar to those of others because of the use of coke in combination with electricity, for the price of coke is cheaper than that of electricity . Also, furnace gas can be further utilized for refining processes. 2) High zinc recovery rate. 3) The process is applicable to any kind of raw zinc materials. 4) High recovery rate of gold, silver, copper and indium. 5) Slag is chemically stable and of comparatively small amount so that it is easy to discard . In the past ten years we have achieved the followings: 1) Establishing an effective environmental protection system. 2) Improvements in the plant and of equipments for reducing energy and labor costs . The author firmly believes that the resistance electrothermic zinc distillation process employed at Mikkaichi Smelter has been and will be playing an important role in zinc production in Japan.