Tellurium metal recovery from copper smelter residues: A short-route via sulfide leaching and precipitation by sodium sulfite

Conventional methods for processing copper anode slime are often hampered by lengthy workflows and low tellurium recovery efficiencies. To overcome these limitations, this study introduces a novel two-stage process combining sulfide leaching and potential-controlled precipitation for tellurium recovery from copper telluride residue. Thermodynamic analysis and experimental characterization were used to elucidate the underlying reaction mechanisms, and key process parameters were systematically optimized. During sulfide leaching, tellurium from copper telluride is displaced by sulfide ions and dissolved3 into solution predominantly as ditelluride anions, achieving a tellurium leaching efficiency of 96.9 %. In the subsequent potential-controlled precipitation stage, the dissolved ditelluride ions were oxidized by sulfite to elemental tellurium, precipitating with 99.1 % efficiency. After washing, the final tellurium powder exhibited a purity exceeding 99.0 %. The proposed process significantly simplifies the workflow, achieves high tellurium recovery, and enhances environmental performance by operating under alkaline conditions that prevent toxic gas emissions and reduce equipment corrosion. This work demonstrates a promising and sustainable alternative for industrial tellurium recovery from copper telluride residue.