从钯银合金废料中回收钯的实验研究

以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。

Study on Recovery of Pd from Pd-Ag Alloy Scrap

Palladium was recovered by the process of dissolution with nitric acid, precipitation of AgNO3 with hydrochloric acid, purification of Pd with the method ofdichloro-diammine palladium and reduction with hydrazine hydrate from Pd-Ag alloy scrap. The results show that when the amount of hydrochloric acid is 2 mL/200 mL mixed acid solution and the reaction time of 1h, the precipitation rate of Ag reaches 99.98%. When the optimum solution pH are controlled at 8 and 1.5 respectively during the process of ammonia complexation and hydrochloric acid acidification precipitation, the purity of dichloro-diammine palladium washed by warm water 3 times reaches more than 99.99%. The recovery rate of palladium of the whole process is greater than 90% and sponge palladium of which purity greater than 99.99% and average particle size no lager than 0.5 μm is prepared.