Sumitomo Metal Mining Co., Ltd. (SMM) is the only one producer of electrolytic nickel and cobalt in Japan. The nickel and cobalt business of SMM, started in 1939, is the history of technological innovation and development. As the major projects developed in the past, SMM underwent a conversion to nickel matte electro-refining process in 1970, a establishment of cobalt refining process with an introduction of Mixed Sulfide raw material in 1975, a conversion to Matte Chlorine Leach Electro-winning process (MCLE) in 1992, and 1nnovations of Cobalt Electro-winning and Nickel Chemical process technology in 1999. Throughout these technological developments, in 1998, SMM has accomplished to increase the production capacity of electrolytic nickel up to 3,000t/M.
Furthermore, in 2004, SMM constructed a High Pressure Acid Leach (HPAL) plant in Parawan Island, Philippine, where all the SMM's refining technology was integrated. To treat the Nickel/Cobalt Mixed Sulfide (MS) produced at the HPAL plant, SMM has improved the MCLE process at Niihama Nickel Refinery. Today, applying MCLE and HPAL technology, SMM treats the oxide Laterite Ore and constantly produces electrolytic nickel with very high quality.