钼精矿真空分解工艺热力学分析

Thermodynamic analysis of vacuum decomposition process of molybdenum concentrate

对钼精矿真空分解工艺中的关键性环节进行了热力学分析，并进行了真空分解试验验证。结果表明：控制炉内压力在低于100Pa、分解温度在1773~2073 K范围，实现钼精矿分解得到金属Mo完全可能。钼精矿中As2S3、SnS2、PbS直接以硫化物形式升华去除，而Bi2S3则更容易分解为Bi蒸气和S蒸气，直接以气态形式去除。CuS在较低温度下容易分解为Cu2S和S蒸气，而要使Cu2S分解为Cu蒸气将Cu去除，则需要更高的温度。硫磺可以通过冷凝的方式回收，硫磺回收的温度区间为392~490 K。通过试验得到Mo含量达到93.69%的金属钼球和S含量达到98.6%的硫磺产品，金属Mo中P、S、Cu、As、Pb和Sn等杂质元素较少。

The key steps of thermal decomposition process of molybdenum concentrate in vacuum were thermodynamically analyzed and verified by the vacuum decomposition experiment. The results show that the thermal decomposition process of molybdenum concentrate in vacuum is feasible when the temperature is in the range of 1773？2073 K and the furnace pressure is less than 100Pa. PbS, SnS2 and As2S3 in the molybdenum concentrate can directly volatile into gas, and Bi2S3 is more likely to decompose to Bi and S vapors and volatilize directly, and CuS decomposes to Cu2S easily, but Cu2S is difficult to decompose unless it is treated under a higher temperature and a lower pressure. The calculated suitable temperature range for sulfur recovery in this process is 392？490 K. The Mo content of molybdenum metal ball obtained by experiments is 93.69% and the S content of sulfur products reaches 98.6%. The impurity elements, such as P, S, Cu, As, Pb, Sn, in the molybdenum products are very low.