以氯化钠-碘化钾-丙醇体系萃取分离金(Ⅲ)

Separation of Gold(Ⅲ) by Extraction with the System of NaCI-KI-Propanol

试验在氯化钠存在下,碘化钾-丙醇体系萃取分离以AuI_4^-络阴离子状态存在的金(Ⅲ)的最佳条件,结果表明:当溶液中碘化钾、氯化钠和丙醇的浓度分别为每升中0.3 g,200 g和300 mL,且溶液的酸度为pH 3.5时,能使AuI_4^-定量萃取,即在总体积为10 mL的溶液中,含碘化钾3 mg,氯化钠2 g和丙醇3 mL。萃取分离50μg金(Ⅲ)时,1 mg铁(Ⅱ)、镍(Ⅱ)、锰(Ⅱ)、铝(Ⅲ)、锌(Ⅱ)、钴(Ⅱ)、镓(Ⅲ)等离子基本不被萃取,而与上述离子分离,金(Ⅲ)的萃取率达99.7%以上。

Optimum conditions for the extraction of auric ion as anionic complex AuI4^- into propanol in the presence of sodium chloride were studied. It was found that quantitative separation of Au（Ⅲ） was achieved from a solution of pH 3.5, and containing 0. 3 g of KI, 200 g of NaC1 and 300 mL of propanol in 1 L of solution. As a total volume of 10 mL （aqueous phase） was taken in the extraction process, 3 mg of KI, 2 g of NaC1 and 3 mL of propanol were added. As shown by the experimental results, 50 μg of Au（ Ⅲ） was separated from 1 mg of Fe（Ⅱ ）, Ni（ Ⅱ ）, Mn（ Ⅱ）, AI（ Ⅲ）, Zn（ Ⅱ ）, Co（ Ⅱ ） and Ga（ Ⅲ）, with values of extraction rate of Au（ Ⅲ） over 99.7 %.