钨铼合金电化学溶解及沉淀分离研究

Study on electrochemical dissolution and precipitation separation of W-Re alloy

摘要:

针对钨铼合金废料,采用电化学溶解法使钨、钼、铼在氢氧化钠碱性溶液中完全溶出,再采用氯化钙沉钨钼和氯化钾沉铼进行了电解溶液的选择性沉淀分离。结果表明：(1)钨铼合金废料电化学溶解的适宜工艺参数为：槽电压2.5V,NaOH浓度100g/L,电解温度30-40℃,极距20-30mm,钨铼离子总浓度控制在30-35g/L,在此条件下,钨、钼、铼溶出率均大于99%,电流效率高达99%以上,且丝状废料较块状废料更好电溶；(2)钨铼电解溶液选择性化学沉淀分离的适宜工艺参数为：反应温度80℃,CaCl₂用量为3倍理论用量,溶液OH^_-浓度9.5g/L,溶液W离子浓度为23.18g/L,反应时间2h,在此条件下,钨、钼沉淀率分别为99.86%和99.55%；(3)经过上述2道工序后,钨、钼回收率分别达到98.86%和98.55%,所得CaWO₄/CaMoO₄混合物形貌为球形颗粒,且制得KReO₄白色晶体。

Abstract:

In view of the waste of W-Re alloy, the electrochemical dissolution method was used to make W, Mo and Rre completely dissolved in the alkaline solution of sodium hydroxide, and then the selective precipitation separation of the electrolytic solution were performed.by using calcium chloride to precipitate W-Mo and potassium chloride to precipitate Re. The results show that: (1)The suitable process parameters for electrochemical dissolution of W-Re alloy waste are: cell voltage 2.5V, NaOH concentration 100g/L, electrolysis temperature 30-40℃, electrode distance 20-30mm, and the total W-Re ion concentration is controlled at 30-35g/L. Under these conditions, the dissolution rate of W, Mo and Re are all more than 99%, the current efficiency is over 99%, and the wire waste is better than the block waste to be eletrochemically dissolved. (2)The optimum technological parameters for the selective chemical precipitation separation of W-Re electrolytic solution are: reaction temperature 80℃, CaCl₂ dosage 3 times of theoretical dosage, OH^_- concentration 9.5g/L, W ion concentration 23.18g/L, reaction time 2h. Under these conditions, the precipitation rates of W and Mo are 99.86% and 99.55%, respectively. (3)After the above two processes, the recovery rates of W and Mo are 98.86% and 98.55%, respectively. The morphology of CaWO₄/CaMoO₄ mixture is spherical, and KReO₄ white crystals are obtained.