(云南大學(xué) 化學(xué)科學(xué)與工程學(xué)院，昆明 650091)
摘 要: 研究酰胺N503和TBP從堿性氰化液中萃取低濃度Au(Ⅰ)，考察N503體積濃度、水相pH值、TBP濃度、NaCl濃度、改性劑種類和相比等因素對(duì)萃取率的影響。結(jié)果表明：當(dāng)溶液的pH在7~11范圍內(nèi)，Au(Ⅰ)的萃取率均大于98%；當(dāng)pH＞11后，Au(Ⅰ)的萃取率顯著變小；盡管TBP的濃度對(duì)Au(Ⅰ)萃取率的影響較小，但提高TBP濃度可以提高萃取pH50值。對(duì)礦山浸出液的萃取結(jié)果表明，N503/TBP萃取體系對(duì)金具有良好的選擇性, 其萃取金屬氰配陰離子的由難至易的次序?yàn)镕e(CN)64−＞Ni(CN)42−＞Zn(CN)42−＞Cu(CN)32−＞Au(CN)2−。
關(guān)鍵字: 溶劑萃取；KAu(CN)2；N, N′-二(1-甲基庚基)乙酰胺；磷酸三丁酯
（School of Chemical Science and Technology, Yunnan University, Kunming 650091, China）
Abstract:The extraction of trace Au(Ⅰ) from alkaline cyanide solution by N, N′-di(1-methylheptyl) acetamide (N503) and tri-butylphosphate (TBP) was studied. The influence of several variables on the gold extraction, including the N503 volume fraction, pH value of the solution, TBP concentration, NaCl concentration and phase ratio(A/O) in aqueous phase were investigated. The results show that almost all of Au(Ⅰ) in the aqueous phase can be extracted into the organic phase when the volume fraction of N503 is more than 10% and pH value of the solution is in the range of 7−11, and the extraction rate is more than 98%. When pH＞11, although TBP concentration has little effect on the extraction rate of Au(Ⅰ), the increase of TBP concentration can increase pH50 value of N503/TBP extraction system. The experiments with a real cyanide leaching solution show that the extractive selectivity for different metal ions from difficult to easy is Fe(CN)64−＞Ni(CN)42−＞Zn(CN)42−＞Cu(CN)32−＞Au(CN)2−.
Key words: solvent extraction; KAu(CN)2; N, N′-di(1-methylheptyl) acetamide; tri-butylphosphate
