用三烷基氧化膦从氰化浸出液中萃取低浓度金

Solvent extraction of trace gold(Ⅰ) from alkailne cyanide solution by trialkylphosphine oxide

研究了三烷基氧化膦(TRPO)-磷酸三丁酯(TBP)-煤油萃取体系对氰化浸金液中低浓度金(Ⅰ)的萃取和反萃取能力,结果表明,尽管TRPO体系中添加TBP对金(Ⅰ)的萃取率影响很小,但一定量的TBP能提高体系的反萃效果。考察了料液pH值、硫酸锂浓度等因素对萃取率的影响,探讨了不同的反萃温度、反萃相比对负载有机相中金(Ⅰ)的反萃效果。结果表明,采用TRPO-TBP-煤油组成的有机相,对金(Ⅰ)质量浓度为9.5 mg/L、盐析剂硫酸锂浓度为1.0 mol/L的碱性氰化液在相比A/O=1∶1条件下进行萃取时,金(Ⅰ)的单级萃取率可达95%以上;反萃温度越高,相比(A/O)越大,反萃效果越好,可以将大部分金(Ⅰ)反萃出来。

Both solvent extraction and stripping of trace gold （Ⅰ） from alkaline cyanide solutions were studied by using trialkylphosphine oxide （ TRPO ） - tributylphosphate （TBP） - kerosene and trialkylphosphine oxide - kerosene.The results demonstrated that although TBP concentration has little effect on the extraction rate of gold（ Ⅰ）, a certain volume fraction of TBP can improve the stripping rate of gold （Ⅰ） from loaded organic phase. The effect of the concen-tration of lithium sulfate and the pH in feed on the percentage extraction of gold （Ⅰ） was researched. The effect of temperature and phase ratio （A/O） on stripping gold （Ⅰ） from organic phase loaded gold （Ⅰ） was also discussed. The re-suhs showed that the system gave high extraction yield for gold, and gold （Ⅰ） could be extracted more than 95 % by TRPO -TBP -kerosene when the concentration of gold （Ⅰ） and Li2SO4 were 9.5 mg/L and 1.0 mol/L respectively and the A/O = 1： 1. The loaded organic phase could be almost totally stripped by higher temperature and larger phase ratio （A/O）.