(昆明理工大學 冶金與能源工程學院，昆明 650093)
摘 要: 研究Mextral54-100(HA)和Mextral54-100+TRPO(HA+TRPO)兩種萃取體系從氨-硫酸銨溶液中萃取分離鋅鎘的性能，確定出鋅鎘分離的最佳工藝。結(jié)果表明：HA+TRPO萃取體系在初始pH為7.2時對鋅具有較高的選擇性萃取能力，而不同pH條件下兩種萃取體系對鎘的萃取能力均很低。因此，宜采用HA+TRPO體系在初始pH為7.2條件下萃取鋅，鎘不被萃取而留在溶液中，實現(xiàn)鋅與鎘的分離。對于鋅的萃取，采用0.4 mol/L HA+0.05 mol/L TRPO的協(xié)同萃取體系，在溫度為25 ℃，初始pH為7.2，O/A相比為1:1的條件下，經(jīng)2級萃取，鋅萃取率為99.2%，鎘的萃取率小于5%；對負載鋅有機相，在溫度為25 ℃，相比為2:1，硫酸濃度為0.1 mol/L的條件下，經(jīng)2級反萃，鋅反萃率為99.9%。萃余液中的鎘可通過化學沉淀法將其沉淀回收。通過選擇合適的萃取體系和萃取條件，獲得了氨-硫酸銨溶液中萃取分離鋅和鎘的最佳工藝流程和技術參數(shù)。
關鍵字: 溶劑萃取；β-二酮；氨性溶液；鋅鎘分離
（Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The performances of extraction systems, Mextral54-100 (HA) and Mextral54-100+TRPO (HA+TRPO), on extraction and separation of zinc and cadmium from ammoniacal/ammonium sulfate solutions were investigated, and the optimal process of zinc-cadmium separation was determined. The results show that high selective extractability of zinc is achieved with HA+TRPO extraction system at initial pH 7.2, while low extractabilities of cadmium are achieved with both extraction systems at different pH values. Therefore, it is supposed to extract zinc with HA+TRPO system at initial pH 7.2, and cadmium is left in the solution as it can not be extracted, which achieves the separation of zinc and cadmium. For extraction of zinc, the extraction ratio of zinc reaches 99.2% with two extraction stages under the conditions of 0.4 mol/L HA+0.05 mol/L TRPO synergistic extraction system, 25 ℃, initial pH 7.2, and phase ratio (O/A) 1:1, while the extraction ratio of cadmium is less than 5%. For loaded organic phase containing zinc, the stripping ratio of zinc is 99.9% with two stripping stages. The cadmium consisting in extraction raffinate can be recycled by chemical precipitation method. In this work, by means of selecting the appropriate extraction system and extraction conditions, the best technical process and parameters for extraction and separation of zinc and cadmium from ammoniacal/ammonium sulfate solutions are acquired.
Key words: solvent extraction; β-diketone; ammoniacal solution; zinc-cadmium separation
