不同金属硫化物从钨酸盐溶液中除钼的效果

针对钨冶炼过程中钨钼分离这一关键问题,研究了利用CuS,CoS,NiS,PbS,FeS,ZnS和HgS等金属硫化物从钨酸盐溶液中除钼的效果.对含钼的Na2WO4或(NH4)2WO4溶液用Na2S或(NH4)2S 进行硫化处理,使其中的MoO2-4转化为MoS2-4,然后加入上述金属硫化物进行除钼.结果表明,CuS,CoS和NiS在Na2WO4或(NH4)2WO4溶液中均具有良好的除钼效果,综合考虑经济、环保等因素,认为CuS是最经济合理的钨钼分离新试剂.考察了试剂用量、反应温度和溶液pH值对除钼效果的影响,并获得了最佳除钼工艺条件,即在CuS试剂用量为理论量的3～4倍、室温下搅拌反应1h的条件下,可使溶液中的Mo从0.6～0.77g/L降至0.007～0.02g/L,除钼率达96.0%～98.5%,整个除钼过程中钨的回收率达99.75%以上.

Removing molybdenum from tungstate solution with metal sulfides

The effect of removing molybdenum from tungsten solution by using metal sulfides, such as CuS, CoS, NiS, PbS, FeS, ZnS and HgS, was studied. After the molybdenum contained in Na_2WO_4 or (NH_4)_2WO_4 solution was sulfurized from MoO~(2-)_4 into MoS~(2-)_4 by using Na_2S or (NH_4)_2S, the metal sulfide was added into the solution to remove MoS~(2-)_4. It is shown that CuS, CoS and NiS are very effective for removing Mo from Na_2WO_4 or (NH_4)_2WO_4 solution. Considering the economic and environmental protection factors, CuS is considered as the proper reagent of removing Mo. The effects of the amount of metal sulfide used, the pH of solution and temperature on removing Mo from tungstate solution were studied. Under the optimum conditions, the Mo concentration can be reduced from 0.60.77 g/L to 0.0070.02 g/L, the efficiency of de-molybdenum is 96.0?.5%, and the recovery of tungsten reaches 99.75% in this process.