SMM Aims to Keep 7.5t/y Gold Production at Hishikari Mine

Hishikari mine of Sumitomo Metal Mining (SMM), mining gold ores in Kagoshima Prefecture, Japan, continues to produce 7.5 tonnes of gold per year under the mid-term management plan of SMM group, with operation know-how cultivated in 20 years since its start to deal with various grade ores. Toward the next 3-year management plan, SMM aims to improve the productivity of the mine more and to train human resources there who can contribute to SMM group’s development of offshore mines. Hishikari mine is the shallow, hydrothermal and vein type ore deposit of gold and silver. The averaged ore grade is 40.7 grams of gold per tonne, highest level in the world. It started operation in 1985, which is the newest and the last metal mine in Japan. The total gold production of Hishikari would exceed 150 tonnes at the end of March 2006 since its start, which reached 144.2 tonnes at the end of March 2005. The gold production of Hishikari is expected to achieve twice of Sado gold mine in the short term, which was already closed. Gold ores are mainly delivered to Toyo works of SMM, which has the copper smelting process, and smelted to gold ingots.SMM mines around 185,000 tonnes of gold ore per year at Hishikari during the current 3-year business plan. One of management know-how is to keep the stable gold production volume. Generally there are various grade ores in mining sites even with the high grade vein. They must cope with low grade veins and control the mining volume in order to save the gold output volume.SMM plans to increase the mining volume to 190,000 tonnes per year improving the output system and to keep 7.5 tonnes of the annual gold production at Hishikari. The mining cost of Hishikari is not cheaper than overseas gold, when the firm must treat hot spring water there. However, SMM aims to advance the productivity of the mine more with the technology improvement and the equipment renewal. SMM group has advanced the overseas resource development most actively among Japanese non-ferrous metal smelters. SMM also expects Hishikari mine to become the place to cultivate mining technologies and management know-how including exploration of minerals.