Top-blown injection smelting and converting: The Mitsubishi process

The Mitsubishi process is a continuous copper smelting and converting process comprising three steps—smelting of raw materials by injection, separation of slag and matte, and direct converting of high-grade matte. Since commercial operation began in 1974, the hearth productivity has been doubled, and several other improvements have been made, including higher-grade matte smelting and the treatment of various secondary materials. Because the Mitsubishi process is superior to the conventional process, it was decided to construct a larger unit of the Mitsubishi furnaces to replace the two existing smelter lines. This article discusses various technical considerations.