(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 對(duì)比研究不同萃取體系下硝酸-磷酸混合溶液中鎢的萃取-反萃行為，從萃取效率、分相程度及反萃效率等方面考慮選取仲碳伯胺萃取劑N1923作為鎢的萃取劑，系統(tǒng)研究N1923對(duì)鎢的萃取-反萃行為，確定了最佳的萃取/反萃工藝參數(shù)。在最優(yōu)工藝參數(shù)下處理配制含有磷鎢酸的硝酸-磷酸混合溶液，即在20%N1923(體積分?jǐn)?shù))+磺化煤油組成的有機(jī)相體系、相比1:1、溫度20 ℃、接觸時(shí)間10 min的條件下，鎢萃取率高達(dá)99.9%；反萃率條件為：溫度50 ℃、相比2:1、氨水濃度12.5%(質(zhì)量分?jǐn)?shù))、接觸時(shí)間10 min，鎢單級(jí)反萃率可達(dá)93.5%。在優(yōu)化條件下萃取硝酸-磷酸混合溶液浸出白鎢礦的實(shí)際料液，鎢的萃取率達(dá)到99.9%以上，反萃時(shí)通過(guò)提高相比和氨水濃度的手段，使反萃液中WO3濃度提高到200g/L以上，反萃率達(dá)到98%以上。
關(guān)鍵字: 硝酸磷酸混合溶液；白鎢礦；磷鎢酸；溶劑萃取；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
