LEACHING OF GOLD FROM PRINTED CIRCUIT BOARDS SCRAP OF MOBILE PHONES

摘要

Every year the natural gold reserves have declined worldwide. In parallel, has increased the demand for this metal, especially for use in the electrical and electronics industry. One way to minimize this problem would be the recovery of this metal contained in printed circuit boards (PCB) of mobiles phones that are discarded after use. In this work a commercial gold stripping (cyanide-based) and, alternatively, thiosulfate in ammoniacal medium, under several conditions of concentration, time and temperatures was tested to leaching gold. In leaching tests whole PCBs were used and the solutions obtained were analyzed by atomic absorption spectroscopy. The results show that, in the terms of efficiency, the commercial stripping is still the best alternative because with this product the extraction rate reached 88% of the gold present on the PCBs, while the extraction rates obtained with thiosulfate reached only 50%. However, the thiosulfate solutions have great environmental advantages.