Vacuum Gasification-Directional Condensation for Separation of Tellurium from Lead Anode Slime
Zhe Gao, Xiangfeng Kong, Jiafei Yi, Bin Yang, Baoqiang Xu, Dachun Liu, Jian Wu, Heng Xiong
Abstract
Tellurium is the indispensable base material of semiconductors in solar panels. Traditional tellurium recycling, a highly complicated separation process, has exhausted reagents and energy sources whilst producing waste residue and water containing multitudinous heavy metal that is hugely harmful to the ecological environment. A clean and eco-friendly vacuum distillation-directional condensation treatment was investigated for its potential to recycle tellurium from tellurium-rich lead anode slime (TLAS). The optimal distillation temperature and response time conditions of 1173 K and 50 min were obtained based on a large number of experiments. Gasification results indicated that under the optimal conditions of distillation temperature 1173 K, constant temperature time 50 min, and system pressure 5–15 Pa, 92% of tellurium was volatilized and enriched into the condenser from TLAS. Condensate results revealed that 88% of elemental tellurium was directly recovered in the volatile matter. The appropriate gasification-condensation processes realized a clean utilization to extract tellurium and separate multi valuable metals effectively.