(中南大学 冶金与环境学院，长沙 410083)
摘 要: 针对现行含锡二次资源处理工艺尚存在“流程长、污染重、能耗高”等问题，以锡精炼过程产出的锡铜渣为原料，开展基于隔膜电积锡回收新工艺试验研究。结果表明：在液固比为5:1、盐酸为4 mol/L、温度50~60 ℃的条件下，锡铜渣中98%以上的锡被浸出；在温度为30 ℃、Na2S用量为理论量的1.3倍、反应时间15 min和BaCO3用量为理论量的3倍的条件下，溶液中的铜、铅可以降低到50 mg/L以下。采用隔膜电积技术对净化后液进行锡电积试验研究表明，在阴极液中[Sn2+] 80 g/L、盐酸3 mol/L、电流密度200 A/m2及电积温度40℃的优化条件下，可以得到致密平整的阴极锡，阴极电流效率大于98%，阴极锡纯度大于99%，吨锡电耗小于1200 kW·h。阳极再生的SnCl4溶液可以作为浸出剂返回浸出锡铜渣，实现流程的闭路循环。
关键字: 锡铜渣；氯化浸出；净化；隔膜电积；锡；清洁工艺
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:In view of the current tin secondary resource treatment processes existing problems, a new process based on membrane electrodeposition was studied to recover tin from tin-copper slag. The results show that under the solid-to-liquid ratio of 5:1, hydrochloric acid of 4 mol/L, temperature of 50-60 ℃, 98% tin can be leached from tin-copper slag. Under the conditions of 30 ℃, 1.3 times dosage of stoichiometric Na2S, 15 min duration, and 3 times dosage of stoichiometric BaCO3, the Cu2+, Pb2+ in the leach solution can be reduced to below 50 mg/L. The purified solution was subjected to membrane electrodeposition. Under catholyte [Sn2+] of 80 g/L, [HCl] of 3 mol/L, current density of 200 A/m2 and electrodeposition temperature 40 ℃, a compact and smooth cathode tin can be obtained from cathode. The current efficiency is more than 98%, and tin purity is more than 99%, power consumption is less than 1200 (kW·h)/t. The resultant SnCl4 solution in anode compartment can be reused as leaching agent for leaching, which achieves the closed-circuit circulation process.
Key words: tin copper slag; chloride leaching; purification; membrane electrodeposition; tin; clean process
