从复杂碲铜物料中回收碲的工艺研究

Technical Research on Recovering Tellurium from Material Containing Tellurium and Copper

以某公司复杂碲铜物料为原料，采用双氧水氧化浸出-草酸沉铜-还原碲工艺回收复杂碲铜物料中的碲。研究了浸出温度、H2 SO4浓度、双氧水加入量、液固比、浸出时间对碲浸出效果的影响，草酸钠过量系数和反应温度对沉铜效果的影响以及亚硫酸钠用量对还原效果的影响。实验结果表明，在H2 SO4浓度110 g/L、双氧水加入量为理论量的1．2倍、液固比6∶1、浸出温度80～85℃、浸出时间4 h时，碲、铜浸出率均在99％以上；在草酸钠为理论量的1．2倍、反应温度65～75℃时，沉铜率达99．6％；在亚硫酸钠用量为理论量的1．6倍时，碲的还原率达99．6％。碲以碲粉的形式回收，铜以草酸铜的形式回收，碲、铜回收率分别为98．5％和98％。

With material containing tellurium and copper as raw material, a study on tellurium recovery by adopting a process composed of leaching with hydrogen peroxide oxidation, copper precipitation with oxalic acid and tellurium reduction is reported. Effects of H2 SO4 concentration, hydrogen peroxide concentration, liquid-solid ratio, leaching temperature and time on tellurium leaching rate, excess coefficient of sodium oxalate and reaction temperature on copper precipitation,as well as effects of sodium sulfite dosage on tellurium reduction were all investigated. Results showed that, with H2 SO4 concentration at 110 g/L, the dosage of hydrogen peroxide at 1.2 times of theoretical value, liquid-solid ratio of 6∶1, leaching temperature at 80~85 ℃, leaching time of 4 h, the leaching rates of tellurium and copper could be over 99%. With the dosage of sodium oxalate at 1.2 times of theoretical value and reaction temperature at 65~75 ℃, copper precipitation rate reached 99. 6%. With the dosage of sodium sulfite at 1. 6 times of theoretical value, the reduction rate of tellurium could be up to 99.6%. Tellurium was recovered in the form of powder and copper was recovered as copper oxalate, with corresponding recoveries of 98.5% and 98%.