抄録
PT Smelting is a joint venture company (Mitsubishi Materials; 60.5, Freeport Indonesia; 25, Mitsubishi Corp. 9.5 and Nippon Mining and Metals 5%) established on 7 February 1996 to construct and operate a copper smelter and refinery in Indonesia. The construction work started in 1996 and completed in August 1998 after two years construction period. Test operation started in December 1998 and commercial delivery of cathode copper commenced in May 1999. Designed capacity of the plant is 200,000 tons of cathode copper from concentrate supplied from Grasberg copper mine in Papua of PT. Freeport Indonesia. The Mitsubishi process is applied to the smelter and ISA process is introduced to the refinery.
In 1999 the operation was 66% of designed capacity, 95% in 2000 and in 2001 the cathode production exceeded the design figure by 7%. About 25% of cathode copper is delivered to domestic customers and the rest to south east Asian countries such as Thailand, Malaysia, Taiwan, Singapore and Vietnam. All the sulfuric acid is sold to the next- door fertilizer plant and all the slag is delivered to the domestic cement industry.
Japanese assistant team for starting-up stayed 5 months. After they left from Gresik, all the operations and maintenance work have been performed 100 % by Indonesian operators with small number of Japanese supervisory engineers.
The sulfur fixation rate is over 99.7% and the effluent meets the stringent Indonesian standards. Clean operation of the Gresik smelter and refinery has attained by a full support from surrounding communities.
