从复杂碲铜物料中回收碲的工艺研究

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、H2SO4浓度、双氧水的加入量、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。试验结果表明:在H2SO4浓度110 g·L-1、双氧水的加入量为理论量的1.2倍、液固比6∶1、浸出温度80~85℃、浸出时间4 h时,碲、铜浸出效果最好;在草酸钠为理论量的1.2倍、反应温度65~75℃时,沉铜效果最好;在亚硫酸钠用量为理论量的1.6倍时还原沉碲的效果最好。碲以碲粉的形式回收,铜以草酸铜的形式回收,碲、铜的回收率分别为98.5%和98%。

A Study on Recovering Tellurium from Complex Materials Containing Tellurium and Copper

With some tellurium copper recovered by using the process of hydrogen complex materials as raw material, tellurium is peroxide oxidation leaching-oxalic acid copper deposition-tellurium reduction. Studies are made on the effects of H2SO4 concentration, hydrogen peroxide concentration, liquid-solid ratio, leaching temperature, leaching time on the tellurium leaching results, the influence of excess coefficient of sodium oxalate and reaction temperature on copper deposition and the influence of sodium sulfite dosage on the tellurium reduction. The test results show that the best effects of tellurium and copper leaching can be obtained under the following conditions such as H2SO4 concentration of 110 g .L-1, hydrogen peroxide dosage of 1.2 times the theoretical amount, liquid-solid ratio of 6：1, leaching temperature of 80-85 ℃ and leaching time of 6 h . When the sodium oxalate concentration and reaction temperature are 1.2 times the theoretical amount and 65-75 ~C respectively, the result of copper precipitation is the best. When the sodium sulfite dosage is 1.6 times the theoretical amount, the result of tellurium reduction is the best. Tellurium is recovered in the form of tellurium powder while copper is recovered in the form of copper oxalate. The recovery rates of tellurium and copper are 98.5% and 98%, respectively.