新型硫化剂在Na₂WO₄溶液中制备硫代钼酸盐

来源期刊：中南大学学报(自然科学版)2002年第1期

论文作者：曹佐英 张启修 肖连生

文章页码：28 - 31

关键词：钨;钼;硫代钼酸钠;分离;硫化剂

Key words：tungsten; molybdenum; sulfidizing agent; sodium thiomolybdate; separation

摘    要：用离子交换法分离P,Si,As,Mo制取高纯APT,需要用硫化剂Na₂S或NaHS等从钨酸钠溶液中使钼酸盐转化为硫代钼酸盐,用离子交换法吸附硫代钼酸根从而实现钨钼分离.这些硫化剂价格较高,使除钼成本增大.因而,研究一种高效、价格低廉的新型硫化剂非常重要.作者研究了一种比RCS廉价的新型硫化剂R₁CS代替RCS,NaHS,Na₂S和H₂S,考察了新型硫化剂R₁CS在粗钨酸钠溶液中生成硫代钼酸钠的硫代化效果.结果表明,对含WO₃120.256 g/L,Mo 1.457 g/L的实际钨酸钠溶液,控制R₁CS的加入量为Mo的近10倍,在装有回流管的三颈瓶中于106℃搅拌反应2.5 h,反应冷至室温后,用1∶1(体积比)的盐酸在密闭的容器中调节酸度至pH值为8.0~8.4,在70℃磁力搅拌再反应2 h,用3%N₂₆₃单级萃取检查硫代化效果,钼的萃取率可达96%以上,表明运用这种新型硫化剂在Na₂WO₄溶液中制备硫代钼酸盐时成本低,效率高

Abstract: Using the process of ion exchange of removing P, Si, As, Mo to produce high purity APT, sulfidizing agent includingNa₂S, NaHS, H₂S has been used to prepare thiomolybdate fromsodiumtungstate solution, and then to separate thiomolybdate from tungsten. But the price of these sulfidizing agents above is so high that the cost of removing Mo is increased highly. As a result, the research on a new type of sulfidizing agent with highly efficient and lower price is very important. The preparation of sodium thiomolybdate by using a new type of sulfidizing agent whose price is much lower than sulfidizing agent, instead of RCS,NaHS,and Na₂S has been firstly studied in this paper. The experimental results show that the yield of sulpho-complex of MoO^2-₄for one stage extraction can reach over 96% for commercial Na₂WO₄ solution containing WO₃120.257 g/L,Mo 1.457 g/L, when the weight ratio of R₁CS to molybdenum is near 10; and the reaction time is 2.5 h in a round-bottom flask with reflux condenser and stirring at 106℃, then is cooled to room temperature;and the cooled mixture in a pressurized container with magnetic stirring is adjusted to pH=8.0~8.4, then is kept reacting for 2 h at 70℃. This results show that the R₁CS can be successfully applied to preparation of sodium thiomolybdate from sodium tungstate solution which is leached by NaOH solution in simple operation and economic methods.