Kosaka Smelter introduced an Outokumpu-type flash furnace in 1967. The Smelter had long treated “Black Ore” or concentrates separated from it as a metallurgical department belonging to Kosaka mine. It is distinctive feature of Kosaka Smelter that the copper smelter has a really close relationships to an adjacent lead smelter in handling intermediate to each other to recover the valuable metals from “Black Ore”. Since the second oil crisis in 1979 and the appreciation of yen in 1985, the domestic mine arround Kosaka Smelter were closed and it was difficult to open new mine.
Kosaka Smelter has been changed to a custom smelter and devoting to treat the complex sulfide copper concentrates in the world from this change. For the last decade, a progressive diversification of the smelter input has been taking place, impure and complex sulfide concentrate being introduced in increasing proportions compared with the period of “Black Ore” treatment. Kosaka Smelter is believed to be one of the most outstanding smelter, which contribute to the complex sulfide concentrates in the world, with our up-to-date metallurgical technology, this paper described about the experience of practical operation at Kosaka Smelter in the last decade.
