Study On Brine Leaching For Lead Recovery From Different Lead-bearing Residues

Lead, as the fourth important nonferrous metals after aluminum, copper and zinc, is widely used in modern industry and has made great contribution to the social development and human civilization. A large number of literature data show that with the development of national economy and the growth of demand, original mineral resources in China is facing a crisis increasingly dried up. However, secondary lead industry chain started late in China, secondary lead production proportion of refined lead production is low. The effect to relieve the original mineral lead resource shortage is weak. Low grade lead slag produced by electrolytic smelting plant, as raw materials for the resource recycling lead and hazardous waste, should be given enough attention.In view of this, on the basis of hydrometallurgical methods for treating lead-bearing residues, brine leaching was used for lead recovery from lead-bearing tailings in this paper. The main content of the paper and the experimental results are as follows:Lead recovery from manganese anode slime tailings in the NaCl-CaCl2leaching system, Lead extraction efficiency was up to95%under the optimum leaching condition as follows:NaCl concentration350g/L CaCl2concentration20g/L, reaction time30min, temperature80℃stirring speed400rpm and liquid to solid ratio6. Various factors can affect lead extraction efficiency, their primary and secondary order is listed as follows:NaCl concentration> solid-liquid ratio> leaching temperature> leaching time>stirring speedLead ions of lead pregnant leaching solution was precipitated by sodium hydroxide solution, sediment was basic lead chloride with high purity. The cementation of lead with aluminum powder from the brine-leaching filtrate has been investigated, lead ions could be effectively removed. However, the treatment of the precipitate (sponge lead) needs further research.Lead recovery from lead-bearing zinc plant residues in the HCl-NaCl leaching system, lead and silver extraction efficiency could reach90%,80%respectively under the optimum leaching condition as follows:NaCl concentration320g/L, HC1concentration1.5mol/L, reaction time90min, temperature80℃and liquid to solid ratio8. The PbSO4could be recycled effectively by brine leaching method. The precipitation reaction of lead with Sodium Sulfide from the brine-leaching filtrate was proved to be feasible, and got high purity lead sulfide with a little amount of elemental sulfur, in which lead content could reach84.20%.