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キーワード： 銅電解スライム，貴金属，塩素浸出，溶媒抽出，イオン交換 Sumitomo Metal Mining Co., Ltd. produces copper, precious metals and rare metals as by-products at the Toyo Copper Smelter & Refi nery, and nickel and cobalt at the Niihama Nickel Refi nery. Precious metals contained in the nickel ore, are also separated and refi ned at the Toyo Refi nery after concentration.Sumitomo Metal Mining Co., Ltd. has been refi ning precious metals by pyrometallurgical method for 400 years. In recent years Sumitomo renewed the refi ning process using fully advanced hydrometallurgical technology and engineering technology developed by its own. The development circumstances of the new precious metal refi ning processes, constitution of the new process and the operation results of this process is discussed in this paper.

Oxygen probes were applied to a PS converter in copper-making operation, and the oxygen pressures of white metal and blister copper in the converter were measured through the converter's mouth and through a tuyere, respectively. Based on the obtained results, the following reaction mechanism has been deduced.(1) The copper-making stage of a PS converter may be classified into three stages, i.e. the early substage where the tuyeres are completely in white metal, the intermediate substage where both phases of white metal and blister copper coexist in the converter and the tuyeres are in the blister copper, and the final substage where the white metal has disappeared from the converter.(2) In the early stage, direct oxidation of white metal by oxygen gas contained in the reaction air progresses in the vicinity of the tuyeres.Cu 2 S(l) + O 2 (g) = 2Cu(l) + SO 2 (g) ……………………………………………………… (1) (3) In the intermediate substage, the following three reactions proceed near the tuyeres, at the interface of blister copper and white metal phases, and in the bulk of the blister copper, respectively.= SO 2 (g) …………………………………………………………………………… (4) Here the most important factor is that reaction(4) progresses under the condition of P SO 2 1atm. It is not dependent on how high the SO 2 pressure of the waste gas from the converter is. Because the condense phases, i.e. the white metal and blister copper phases, are not in equilibrium with the gas phase.(4) In the final substage, reactions(2) and (4) only proceed because the white metal is no longer in the converter. Some of the blister copper can be excessively oxidized to the extent that Cu 2 O(s) is formed according to equation(5). However the final degree of oxidation of the whole blister copper does not reach this level. KEY WORDS

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