氧化碲粉催化还原制备精碲实验研究

Experimental Research and Scale Production of Refined Tellurium from Tellurium Oxide Powder by Catalytic Reduction Method

摘要: 本文以铜阳极泥氧化酸浸工艺产生的氧化碲粉为原料，通过盐酸浸出–催化还原–洗涤除杂–铸锭制备精碲。实验结果表明，最佳浸出条件即温度为60℃、浸出时间60 min、液固比3:1和盐酸浓度9.4 mol/L时，碲的浸出率为97.6%。催化还原时间为4 h时，碲的还原率为99.9%，该条件下碲的直收率达到97.5%，高于电解法27%~37%。洗涤实验表明还原碲粉中钠，铁和硅等杂质吸附在碲的表面，可通过去离子水和氨水洗涤脱除。还原碲粉经过铸锭后达到牌号Te9999标准。该技术表明工艺简单，碲的直收率高，宜于大规模生产。

Abstract: In this paper, the tellurium oxide powder produced by the oxidation and acid leaching process of copper anode slime is used as raw material to prepare refined tellurium (Te9999) via a series of processes that hydrochloric acid leaching, catalytic reduction, washing and ingot casting, and industrial research. The experimental results show that the leaching rate of tellurium is 97.6% when the optimal leaching conditions are temperature of 60˚C, leaching time of 60 min, liquid-to-solid ratio of 3:1 and hydrochloric acid concentration of 9.4 mol/L. Reduction rate of tellurium is 99.9% when the catalytic reduction time is 4 h. When the catalytic reduction time is 4 h, the reduction rate of tellurium is 99.9%, and the direct recovery rate of tellurium under this condition is 97.5%, which is 27% - 37% higher than the electrolysis method. Washing experiments show that impurities such as sodium, iron and silicon in the reduced tellurium powder are adsorbed on the surface of the tellurium and can be removed by washing with deionized water and ammonia water. The reduced tel-lurium powder reaches the Te9999 standard after ingot casting. This technology shows that the process is simple and the direct yield of tellurium is high, which is suitable for large-scale production.