Selective Separation and Recovery of Tellurium from Copper Anode Slime Using Acidic Leaching and Precipitation with Cuprous Ion

Tellurium is a critical metalloid element that is majorly produced from copper anode slime and is widely consumed in solar energy systems. In this research, a sustainable recovery of tellurium from copper anode slime obtained from Sarcheshmeh Copper Complex, Iran, was investigated. At first, the dissolution of tellurium and other impurities from copper anode slime using sulfuric acid at the atmospheric condition and under pressure in the presence of various oxidants, such as oxygen and hydrogen peroxide was studied. Leaching under pressure using autoclave at 8 bar and 120 °C was concluded as the best leaching route for selective dissolution of tellurium and copper from copper anode slime. The dissolution behavior of the slime impurities was also monitored and considered in the process selection. After the dissolution of tellurium and copper, tellurium precipitation in a form of Cu 2 Te using cuprous ions was investigated. Complete precipitation of tellurium was attained at 80 °C, using both cuprous ion and metallic copper. The cementation method employed has proven the possibility of tellurium ion reduction solely with the metallic copper. The generated cuprous telluride precipitate was eventually alkaline leached and electroplated from solution on a stainless-steel cathode. This recovery process was designed such that to consume the waste products of the main process with the materials that are produced in a copper refinery plant such as copper chips and electrolyte solution. Graphical Abstract