(1. 中国科学院 青岛生物能源与过程研究所，中国科学院生物基材料重点实验室，青岛 266100； 2. 中国科学院 过程工程研究所，中国科学院绿色过程与工程重点实验室，北京 100190)
摘 要: 提出一种大相比鼓泡油膜萃取新方法，从氰化提金废水中萃取回收极低浓度金。考察季铵盐N263萃取体系大相比鼓泡油膜萃取过程的水相流量、油相流量、有机相负载量、有机相再生等因素对极低浓度金萃取回收的影响。结果表明：大相比鼓泡油膜萃取可高效、经济地回收氰化提金废水中的极低浓度金。萃余液中金浓度可降至0.01 mg/L以下，金萃取回收率达99%以上。低浓度金的萃取速率取决于水相流量、气泡表面包覆的有机萃取剂油膜层厚度、以及有机油膜层中的金属离子负载量等。
关键字: 萃取；大相比；油膜；氰化；低浓度；金
（1. CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266100, China; 2. CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China）
Abstract:A new bubbling organic membrane extraction at large aqueous-to-oil phase ratios was suggested for recovery and enrichment of extremely low concentration gold(I) in cyanide wastewaters. The effect from the volume flowing rate of aqueous feed solution and organic phase, metal ion loading in the organic phase and the regenerated organic phase for reusing, on extraction of low concentration gold(I) during bubbling organic membrane extraction by quaternary ammonium salt N263, were investigated. Experimental results indicated that gold(I) cyanides with extremely low concentrations in wastewaters could be economically recovered and enriched efficiently by the suggested new method. Gold(I) concentration in the extraction raffinates could decrease to below 0.01mg/L, and the extraction recovery of gold(I) could reach above 99%. The extraction rate of gold(I) is subject to the volume flowing rate of aqueous feed solutions, the thickness of the organic liquid membrane layer on the surface of gas bubbles, and metal ion loading capacity in the organic membrane layer. The present work suggest a new approach for treatment of the wastewaters from gold cyanide processes.
Key words: solvent extraction; large aqueous-to-oil phase ratios; organic liquid membrane; cyanidation; low concentration; gold
