从含高钼的钨溶液中回收钨钼的研究

Study on Recovery of Tungsten and Molybdenum from High-Mo Tungsten Solution

采用钙盐沉淀-稀盐酸洗涤除Cr-浓盐酸分离钨钼工艺,从废旧高温合金处理过程产生的含高钼的钨溶液中回收钨钼,考察了钙盐沉淀pH值、盐酸浓度、温度、时间以及液固比对钨钼分离的影响。实验结果表明,在钙盐沉淀过程中,控制pH=9.5,CaCl_2过量系数1.2,温度80～90℃,W、Mo沉淀率可达到99%以上;固体沉淀物通过稀盐酸洗涤除Cr,当盐酸浓度为3%时,除Cr率接近100%;未溶解的固体部分在浓盐酸中进行钨钼分离,控制盐酸浓度250g/L,反应温度65℃,反应时间30min,液固比3∶1,可使98%以上的Mo进入溶液,W以钨酸形式沉淀,从而实现钨钼铬的分离。

The process is applied of the calcium salt precipitation-Cr removal by washing in dilute hydrochloric acid and W and Mo separation with concentrated hydrochloric acid to recover the tungsten and molybdenum from high-Mo tungsten solution resulted from the waste superalloy treatment.The effects were investigated of pH value of calcium salt precipitation,hydrochloric acid concentration,reaction temperature,reaction time and liquid to solid ratio on separation of tungsten and molybdenum.The experimental results show that during calcium precipitation,tungsten and molybdenum precipitation rate is more than 99% with pH value of 9.5,CaCl_2 excess coefficient of 1.2,and temperature of 80~90 ℃.Chromium can be removed from solid precipitation by washing with dilute hydrochloric acid,and chromium removal rate get close to 100% with 3% hydrochloric acid concentration.In addition,tungsten in the insoluble solid was separated from molybdenum with concentrated hydrochloric acid.Under the conditions of hydrochloric acid concentration of 250g/L,reaction temperature of 65℃,reaction time of 30 min,and liquid to solid ratio of 3∶1,more than 98% molybdenum dissolves in solution,while tungsten exists in solid form of tungsten acid.Thus,the separation of tungsten,molybdenum and chromium is realized.