从仲钨酸铵结晶母液中回收钨与氨的工艺研究

Recovery of Tungsten and Ammonia from Ammonium Paratungstate Mother Liquor

以氢氧化钙或氧化钙为钙源和苛化源,采用一步法回收仲钨酸铵结晶母液中的钨和氨。化学平衡原理分析和验证实验表明,一步法回收钨和氨技术可行。当Ca^(2+)/NH_4^+计量摩尔比大于0.5时,钨沉淀效果较好,残留液中钨含量低于10 mg/L,溶液中NH_4^+残留浓度小于200 mg/L。

Tungsten and ammonia from mother liquor after crystallization of ammonium paratungstate can be recovered directly with Ca（OH）2 or CaO as resources of calcium and caustification. A chemical equilibrium theory analysis and an experimental study verified that such one-step process is technically feasible for recovering tungsten and ammonia. It is found that Ca^2＋/NH4^＋ molar ratio being more than 0. 5 can result in a better tungsten precipitation,leaving 10 mg/L tungsten in the residue and less than 200 mg/L NH4＋in the solution.