臭化銅含有 DMSO 溶媒を用いた貴金属・レアメタル回収手法の開発

抄録

  We have presented a novel process for recycling gold from secondary sources: Leaching of gold by dimethyl sulfoxide solutions containing copper bromide and precipitation with water, which could offer a number of advantages, including eco-friendliness, ease of operation and low cost. In this work, we applied this process to other metals which are contained in secondary sources, e.g. printed wired board. The mechanism of dissolution was investigated by electrochemical measurements. Metal wires were dissolved in a DMSO solution with 0.2 M of CuBr₂ and 0.2 M of KBr at 343 K. The precipitation of dissolved metals were performed by the addition of water, during which the effects of the amount of water and pH on the recovery rate were investigated. The results of the electrochemical measurements indicate that the anodic dissolution of sample metals in DMSO containing CuBr₂ occurs at relatively negative potentials and is paired with the cathodic reduction of Cu²⁺ to Cu⁺. It was found that gold, silver, copper, tin, cobalt, nickel and zinc were able to be dissolved, all of which can be effectively precipitated by the addition of water with appropriate pH.