Material Flow Analysis bivalent metallic element in the large smelting and processing of anode slime
|School||Central South University|
|Keywords||Copper anode slime Substance flow analysis Precious metals Recycling|
With the sustainable development of industry, human demanding for more and more non-ferrous metal, the world is facing shortage of nonferrous metal resources. Therefore, much more people focus on the recycling of secondary resources. When copper anode slime is rich in valuable metal, it is significant for the recycling of valuable metals from which to drive the development of non-ferrous industry.The substance flow analyses of the recycling status of the valuable metal elements were studied in this work, which was conducted in laboratory simulation of on-site process. This study can explain the situation of the flow & recycling and recovery methods of these metals, and provide guidance for the high-comprehensive utility of these metals in copper anode slime.From the experiments, it was indicated that:the direct yield rate of Ag, Cu, and Se is higher than 94%, while which of Au, Pt & Pd are only 87%,53% respectively in the treatment processes of copper anode slime. About the unrecovered metals, the Te is scattered in the AgCl precipitated solution (20.078%), Ag leached residues (35.947%), Pt-Pd concentrate (30.055%) and the Pt-Pd precipitated solution (12.635%). Nearly 90% of Sb is found in Ag leached residues, only a small part scattered in the AgCl precipitated solution. Bi is distributed in Ag leached residues (38.425%), Pt-Pd concentrate (23.886%), the AgCl precipitated solution (28.98%) and crude Ag powder (8.634%). As is dispersed more seriously, mainly in the AgCl precipitated solution (39.236%), Ag leached residues (46.545%), Pt-Pd concentrate (10.0813%) the Pt-Pd precipitated solution (4.033%).According to the substance flow analysis of the metal, this paper advice that the Au in Au precipitated solution can be accumulated through the extraction, and then restore the gold with anti-extraction; the alkaline hydrolysis is added into the Au precipitated solution for precipitating Bi to improve the recovery rate of Pt and Pd; the ammonia can be replaced by sodium sulfite for leaching Ag. In addition, the Pb can be leached and recovered by ammoniacal ammonium sulphate before the stage of leaching Au; the Te can be recovered through the high pressure acid leaching method of Cu and Te; in the stage of acid leaching Cu, the Bi can be removed by increasing the concentration of sulfuric acid, adding a certain amount of industrial salt and hydrochloric acid; in the acid solution, the Sb can be leached from the Ag leached residues; the As hazards can be removed by adsorption method after enriching the arsenic solution.