2013 年 129 巻 5 号 p. 208-212
There is an increasing trend in the copper smelters to recycle electronic materials, which contain relatively high concentration of platinum group metals. Platinum group metals lost in the slag is increasing with increasing of treated scrap amount. To determine the portion of the platinum group metals chemically dissolved in the slag will be a key factor to improve the recovery of those metals. An experimental study was carried out to determine the solubility of platinum in FeOx-SiO2 slag equilibrated with a pure platinum and the liquid Pt-Cu alloy at 1573 K and the range of oxygen partial pressure from 10-9 to 10-6. The solubility of platinum in the slag tends to increase with increasing oxygen partial pressure and content of copper in the slag. Based on the measured platinum solubility, activity coefficients of platinum oxide in the FeOx-SiO2 slag were derived. The activity coefficients decrease by increasing copper contents in slag. Therefore, lower copper content in the slag tend to lower precious metals dissolution in the slag.