以锌冶炼烟尘为原料制备高纯微球形貌镉粉（英文）

Preparation of high purity cadmium with micro-spherical architecture from zinc flue dust

采用酸浸和对环境友好的除杂方法处理锌冶炼烟尘回收提取高纯镉。结果表明,其最佳条件如下:硫酸浓度90 g/L、液固比6:1、反应温度60°C、浸出时间1.0 h,此条件下镉的浸出率达95.8%。采用Fe Cl3沉淀生成Fe AsO 4和Fe(OH)3来分离重金属和砷,当n(Fe)/n(As)为3:1、p H=6.0时,铁、铅和铜的去除率均超过98.9%,砷的去除率为99.6%。P204用于锌和镉的溶剂萃取分离,最佳萃取条件如下:P204浓度20%(体积分数,室温下用煤油稀释)、p H=3、相比O/A=1:1。在此条件下,锌的萃取率为99.2%。当还原温度为310°C时,镉粉的形貌为均匀球形,晶体结构为立方晶体,得到的镉粉纯度超过99.99%。

This research has focused on the treatment of zinc flue dust by an acid leach process, combining an environmentally suitable impurity removal process to recover cadmium. Optimum conditions were found as follows： H2SO4 concentration 90 g/L, liquid/solid ratio 6：1, leaching temperature 60 ℃ and leaching time 1.0 h. Under these conditions, 95.8% cadmium was recovered. FeAsO4 and Fe（OH）3 precipitates with FeCI3 are found to be highly effective to obtain a high degree of separation of heavy metals and the oxyanions of arsenic from the leachate. The overall separation of arsenic and other heavy metals and precipitate settling rates are optimum at n（Fe）/n（As） ratio of 3：l and pH 6. The removal rates ofFe, Pb and Cu from the solution were greater than 98.9%, and As removal rate was 99.6%. A solvent extraction with P204 was used for the separation of zinc and cadmium. Optimum conditions are obtained as follows： 20% P204 （volume fraction） diluted with kerosene at room temperature, pH 3.0, and varying organic/aqueous （O/A） phase ratio 1：1. The extraction rate of zinc is 99.2% under these conditions. Spherical cadmium particles showing nearly uniform size were produced by hydrogen reduction at 310 ℃ and the crystal structure was cubic. In addition, the purity of the recovered cadmium powder is more than 99.99%.