複雑鉱の混合処理を目的とした八戸共同製錬所の建設と操業改善

抄録

Hachinohe Smelting Company Limited was established on February 1, 1967, as a joint smelter by six nonferrous companies in Japan. In order to treat complex lead-zinc ores, especially some concentrates from black ore in northern district of Japan and concentrates from Huanzala Mine in Peru, it was decided to construct a new smelter at the northern tip of Honshu, adopting the Imperial Smelting Process.
The entire complex was completed at the beginning of 1969, consisting of a sinter plant, acid plant, furnace plant and zinc refinery. The designed production of 4, 500 metric tons of zinc was achieved in July 1969. By expanding the furnace bottom and improving the technology, monthly output was a record 7, 101 metric tons in June 1971.
This paper gives a brief description of the plant developements and improvements. The major items of them are as follows: 1. Total control of the plant by using a supervisory computer.
2. Up draft sintering operation by adopting a process computer.
3. Separate production of dark acid from clean acid by installing a double contact acid plant.
4. Purification and decolorization of dark acid.
5. Increase of the ISF capacity.
6. Treatment of the high copper raw materials.
7. Rationalization of the cadmium process.