INCREASE PRODUCTION AND QUALITY IMPROVEMENT OF ELECTROLYTIC COPPER AT TANK HOUSE IN NAOSHIMA SMELTER REFINERY

摘要

Operation of copper tank house in Naoshima Smelter & Refinery started in 1969. Increase of electrolytic copper production had been mainly carried out in the past by installing more tank house cells and raising current density of commercial cells. However this time increase of production and improvement of quality was achieved without big amount of capital investment, as follows. 1) 22 cells which were used for lead refinery were converted to starter sheet cells for copper refinery. 2) To improve verticalness of starter sheets, electrolysis time for starter sheets was changed from 24hours to 48 hours. 3) Starter sheet preparation machine was modified. 4) Flow amount of electrolyte was controlled at commercial cells. 5) Current efficiency of commercial cells was kept over 96.5% As a result, production of electrolytic copper was increased by 750 T/M and tank house capacity reached to 19,500 T/M.