Platinum in waste Co-Cr-Pt target material was recovered by using a three-step method of oxidizing acid dissolution, precipitation with ammonium chloride and ion exchange. 100 g waste Co-Cr-Pt was totally dissolved at 95℃ for 4 hours by 35 g sodium chlorate in 400 mL HCl. The liquid-solid ratio was 6 mL: 1 /g. Most of the impurities, including cobalt and chromium, were removed from the solution after platinum was selectively precipitated by ammonium chloride. The platinum was further refined by ion-exchange to get rid of residual impurity elements. The purity of the resulting platinum was more than 99.995%, meeting the requirements for the reproduction of Co-Cr-Pt target material. |