(中南大学 冶金与环境学院，长沙 410083)
摘 要: 铜阳极泥经低温碱性熔炼-浸出处理后，铅、砷、硒等进入强碱性浸出液，其中铅和砷分别以Pb(OH)n2-n和AsO43-形式存在。为分离其中的铅、砷等主要杂质元素，通过计算PbS-H2O体系电势-pH图、Ca-As-H2O体系溶解平衡浓度-pH图后，采用硫化沉淀和钙盐沉淀的方式有效去除铅、砷，同时保证硒的低分散度。实验结果表明：采用硫化沉淀，硫化钠过量系数2.5，反应温度20 ℃，反应时间15 min。在此条件下，铅和铜沉淀率都达到99.99%以上，硒损失5%；采用钙盐沉淀，控制溶液pH=10，钙砷比3.5，反应温度90 ℃，反应时间1.5 h。在此条件下，砷沉淀率达到99%以上，硒沉淀率为2.81%。
关键字: 铜阳极泥；浸出液；硒；硫化铅；砷酸钙
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The leaching solution of low-temperature alkaline smelting-leaching process contains selenium, arsenic and lead, which exist in forms of SeO42-, Pb(OH)n2-n and AsO43-, respectively. In order to recover selenium, it is necessary to fully precipitate the lead and arsenic. After calculating the potential-pH diagram of PbS-H2O system and the solubility-pH diagram of Ca-As-H2O system, the lead and arsenic were removed by the sulfurized precipitation and calcified precipitation progress, while ensured the low dispersion of selenium. The results show that the lead can be effectively separated from other metals under the optimum conditions which are stoichiometric requirement of Na2S of 2.5, reaction temperature of 20 ℃, reaction time of 15 min. The copper and lead precipitation can reach 99.99% when the arsenic and selenium precipitation rate is less than 5%. The arsenic precipitation ratio reaches 99% when the reaction conditions are pH=10, n(Ca)/n(As)=3.5, bath temperature of 90 ℃ and reaction time of 1.5 h.
Key words: copper anode slime; leaching solution; selenium; lead sulfide; calcium arsenate
