(1. 中國科學(xué)院 青島生物能源與過程研究所，中國科學(xué)院生物基材料重點(diǎn)實(shí)驗(yàn)室，青島 266100； 2. 中國科學(xué)院 過程工程研究所，中國科學(xué)院綠色過程與工程重點(diǎn)實(shí)驗(yàn)室，北京 100190)
摘 要: 提出一種大相比鼓泡油膜萃取新方法，從氰化提金廢水中萃取回收極低濃度金。考察季銨鹽N263萃取體系大相比鼓泡油膜萃取過程的水相流量、油相流量、有機(jī)相負(fù)載量、有機(jī)相再生等因素對極低濃度金萃取回收的影響。結(jié)果表明：大相比鼓泡油膜萃取可高效、經(jīng)濟(jì)地回收氰化提金廢水中的極低濃度金。萃余液中金濃度可降至0.01 mg/L以下，金萃取回收率達(dá)99%以上。低濃度金的萃取速率取決于水相流量、氣泡表面包覆的有機(jī)萃取劑油膜層厚度、以及有機(jī)油膜層中的金屬離子負(fù)載量等。
關(guān)鍵字: 萃取；大相比；油膜；氰化；低濃度；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
