(1. 中南大学 冶金与环境学院，长沙 410083；
2. 中南大学 稀有金属冶金与材料制备湖南省重点实验室，长沙 410083)
摘 要: 目前钨冶炼企业广泛应用的除钼方法是基于钨钼与硫亲合力的差异，针对该方法中存在的钼硫化剂含硫量低且价格高的问题，提出以五硫化二磷P2S5作为新型硫化剂，通过其水解产生硫氢根为钼的硫化提供硫源的设想，并从热力学角度考察P2S5在水溶液中的水解过程及钨、钼的硫化行为。结果表明：P2S5水解产生钼硫化所需要的硫氢根；同时，在pH值7~9的弱碱性溶液中，n(S)/n(Mo)为8时，硫氢根可使溶液中的MoO42-完全硫化为硫代钼酸根，而WO42-几乎不被硫化。硫化过程中P2S5水解还将产生PO43-，在钨冶炼过程中可用现有技术除去。因此，在钨钼分离工艺中，P2S5有望成为一种新型高效的钼硫化剂。
关键字: 钨；钼；钼硫化剂；五硫化二磷；分离；水解平衡；硫化；热力学
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Hunan Key Laboratory for Metallurgy and Material Processing of Rare Metals,
Central South University, Changsha 410083, China）
Abstract:Currently, molybdenum is removed from tungstate solution by taking the advantage of different affinity towards S between W and Mo. Aiming at the problem of low sulfur content and high price of Mo sulfiding agent existing in tungsten extractive industry, we try to utilize the phosphorus pentasulfide as a new sulfiding agent and wish the generated HS- in the hydrolysis of P2S5 to provide the needed sulfur for Mo-sulfidation. Thus, the hydrolysis equilibrium of P2S5 in aqueous solution and thermodynamic behaviour of W amd Mo sulfidation were studied detail. The results show that the generated HS- in the hydrolysis of P2S5 can provide HS- for Mo-sulfidation. And, when n(S)/n(Mo) is 8 and the solution pH value is 7-9, MoO42- can be completely sulfurized to MoS42-, while tungsten still exists as WO42-. In addition, although the impurity PO43- is generated in the hydrolysis of P2S5, it can be removed easily and economically through the current technology in tungsten extractive industry. Therefore, P2S5 is expected to be a new efficient Mo sulfiding agent in the separation process of W and Mo.
Key words: tungsten; molybdenum; Mo-sulfidation agent; phosphorus pentasulfide; separation; hydrolysis equilibrium; sulfidation; thermodynamics
