(中南大学 冶金与环境学院，长沙 410083)
摘 要: 对比研究不同萃取体系下硝酸-磷酸混合溶液中钨的萃取-反萃行为，从萃取效率、分相程度及反萃效率等方面考虑选取仲碳伯胺萃取剂N1923作为钨的萃取剂，系统研究N1923对钨的萃取-反萃行为，确定了最佳的萃取/反萃工艺参数。在最优工艺参数下处理配制含有磷钨酸的硝酸-磷酸混合溶液，即在20%N1923(体积分数)+磺化煤油组成的有机相体系、相比1:1、温度20 ℃、接触时间10 min的条件下，钨萃取率高达99.9%；反萃率条件为：温度50 ℃、相比2:1、氨水浓度12.5%(质量分数)、接触时间10 min，钨单级反萃率可达93.5%。在优化条件下萃取硝酸-磷酸混合溶液浸出白钨矿的实际料液，钨的萃取率达到99.9%以上，反萃时通过提高相比和氨水浓度的手段，使反萃液中WO3浓度提高到200g/L以上，反萃率达到98%以上。
关键字: 硝酸磷酸混合溶液；白钨矿；磷钨酸；溶剂萃取；N1923
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The extraction behavior of tungsten in nitric acid-phosphoric acid mixed solution was examined with different extraction agents. The results indicate that extraction agent secondary amine extractant N1923 has a satisfied extraction and stripping efficiency of tungsten. Then, the extracting and stripping process of tungsten by N1923 was investigated. During the extracting process, over 99.9% tungsten can be extracted under 20% N1923 (volume fraction) in organic phase system, phase ratio 1:1, temperature 20 ℃ and contact time 10 min. During the stripping process, over 93.5% tungsten loaded on organic phase is stripped with 12.5% ammonium hydroxide under the conditions of phase ratio 2:1, temperature 50 ℃ and contact time 10 min. Based on the research of extracting tungsten from simulate leach solution of scheelite concentrates, N1923 is used to treat the leach solution of scheelite concentrates which is digested by nitric acid phosphate mixture. The applications show that 99.9% tungsten is extracted and a relatively high concentration of ammonium tungstate solution (WO3 is over 200g/L) can be obtained through increasing phase ratio and ammonium hydroxide concentration with a satisfied stripping efficiency of 98%.
Key words: nitric acid-phosphoric acid mixed solution; scheelite concentrate; phosphotungstic acid; solvent extraction; N1923
