日本住友商事于是１９９４年开始研究以煤作还原剂的ＩＤＩ新还原铁生产方法，于是１９９７年秋与美ＳｔｅｅｌＤｙｎａｍｉｃｓ公司（ＳＤＩ）共同在美国兴建还原铁厂该工程总投资约９０００多万美元，年产还原铁约６０万ｔ，经过熔化工序后，每年向ＳＤＩ公司电炉厂提供５０ Therefore, Sumitomo Corporation of Japan started to study IDI new reduction iron production method using coal as reductant in 1994. Therefore, in the fall of 1997, it will jointly establish a reduced ironworks with the United States in the United States with SteelDynamics (SDI) in the United States. The total investment is about 90 million U.S. dollars, Iron reduction of about 600,000 t, after the melting process, the annual supply to the electric furnace factory SDI 50