Lateritic nickel ores were first discovered in Sulawesi in 1909. In 1934 Oost Borneo Maatschappij began exploring for nickel in Pomalaa and mining began in 1938. Ores were exported to Japan until 1942. In that year, Sumitomo Metal took over the mine and used the ores to feed a matte smelter that it built nearby. This plant was destroyed in the Second World War. In 1962 BPU Pertambun, PT Pertambangan Nickel Indonesia and Sulawesi Nickel Development Corp formed a joint venture company to start the Pomalaa mine. In 1968 the venture was consolidated and placed under the control and ownership of PN Aneka Tambang, becoming PT Aneka Tambang in 1974. From 1976, some of the Pomalaa mine feed was sent to a newly built smelter/refinery complex.