硫化铅精矿和废铅膏泥同时浸出过程研究

Research on a Process for Simultaneous Leaching of Lead Sulphide Concentrate and Spent Lead Paste

研究了硫化铅精矿和废铅膏泥同时浸出过程。同时浸出过程涉及两个阶段:(1)在盐酸溶液中,铅精矿中的PbS和废铅膏泥中的PbO、PbO_2、Pb被转化为固体PbCl_2;(2)固体PbCl_2和废铅膏泥中的PbSO_4与MgCl_2反应生成可溶性的配合物MgPbCl_4。第一阶段中的一个关键技术是PbO_2用作PbS的氧化剂,或PbS用作PbO_2的还原剂。两个阶段的总结果是产出了浸出渣和浸出液。从浸出液中可结晶出PbCl_2。第二阶段的过程是铅氯化-湿法冶金中的成熟技术,本研究的重点集中在第一阶段的条件试验。第二阶段采用固定试验条件:浸出温度95℃,溶液中MgCl_2浓度5.5mol/L,浸出时间3h。通过试验确定的第一阶段最佳试验条件:废铅膏泥与铅精矿的质量比3.5∶1,液固比4∶1,溶液pH2.0,转化温度55℃,转化时间4h。试验结果表明,在上述试验条件下,硫化铅精矿和废铅膏泥同时浸出过程的浸出渣含铅达到1.8%,铅浸出率为99.44%。

A process for simultaneous leaching of lead concentrate and spent lead paste was investigated. The process involved two stages: The first is in hydrochloric acid solution, PbS in lead concentrate and PbO、PbO2、Pb in spent lead paste were converted to solid PbCl2;The second is the solid PbCl2 and PbSO 4 in spent lead paste reacted with MgCl 2 to produce soluble complex compound MgPbCl 4. As a key technology in the first stage,PbO2 was used as oxidant of PbS,or PbS was used as reductant of PbO2. The total result of two stages was to produce leach residue and leach solution, from which PbCl2 can be crystallized. The second stage is a mature technology in the chloride hydrometallurgy of lead and focus of this study was centred on condition experiments of the first stage. The second stage used fixed experiment conditions: leaching temperature 95℃, concentration of MgCl 25.5 mol/L and leaching time 3 h. The optimal conditions of the first stage determined by experiments: the mass ratio of spent lead paste and lead concentrate 3.5∶1;the ratio of liquid and solid 4∶1;solution pH 2.0;conversion temperature 55℃;conversion time 4 h. Experiment results indicated that lead content in leach residue from process for simultaneous leaching of lead concentrate and spent lead paste reached 1.8%, leach efficiency of lead 99.44% under the above experimental conditions.