(中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083)
摘 要: 針對(duì)從鎢礦堿性浸出液中直接萃取鎢制取仲鎢酸銨(APT)工藝萃取分相慢、反萃液中WO3濃度偏低的問(wèn)題，采用季銨鹽三辛基甲基氯化銨(Tri-n-octylmethyl-ammonium chloride,TOMAC)為萃取劑，對(duì)從鎢礦蘇打浸出模擬料液中直接萃取鎢進(jìn)行研究，分別考察鎢礦浸出液中Na2CO3濃度、反萃劑組成及濃度對(duì)萃取和反萃取過(guò)程的影響；分別繪制萃取等溫線和反萃取等溫線，并結(jié)合Kremser方程選擇合適的反萃流比以及逆流反萃級(jí)數(shù)，用離心萃取器模擬逆流串級(jí)萃取與反萃取實(shí)驗(yàn)。結(jié)果表明：料液中Na2CO3濃度對(duì)WO3萃取率影響不大，但對(duì)萃取過(guò)程分相性能影響較大；當(dāng)萃取劑濃度為50%(體積分?jǐn)?shù))時(shí)，有機(jī)相飽和萃鎢容量(以WO3計(jì))為91.49g/L；向反萃劑NH4HCO3中加入NH3·H2O，不僅能提高反萃液(鎢酸銨溶液)的穩(wěn)定性，而且有利于提高反萃液中WO3的濃度。實(shí)驗(yàn)條件下分相良好，反萃液中WO3濃度達(dá)到160 g/L左右，雜質(zhì)含量完全可以滿足生產(chǎn)0級(jí)APT的需要。
關(guān)鍵字: 鎢；溶劑萃取；季銨鹽；Na2CO3體系
leaching liquor of scheelite with quaternary ammonium salt
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The direct solvent extraction of tungsten from autoclave-soda leach solution of scheelite using quaternary ammonium salt (tri-n-octylmethy-lammonium chloride, TOMAC) was investigated to solve the problems of slow phase separation and low WO3 concentration in strip liquor which are main disadvantages in the process of direct solvent extraction of tungsten from alkaline medium. The effects of Na2CO3 concentration in leaching solution, composition and concentration of stripping reagent on the extraction and stripping were investigated. The isotherms of the extraction and stripping were plotted, and the optimum flow ratio and stripping stage were determined through Kremser formula. Based on these, the centrifugal extractor was used to simulate the counter current extraction. The results indicate that the concentration of Na2CO3 in feed solution has little influence on the extraction of WO3 but great influence on the phase separation in the extraction, the saturated loading capacity (for WO3) of organic reaches 91.49 g/L when the concentration of extractant is 50%( volume fraction), the addition of NH3∙H2O into NH4HCO3 as the mixed stripping reagent not only improves the stability of stripping liquor, but also increases the WO3 concentration in stripping liquor. The phase separation is good during the extraction and stripping, and the concentration of WO3 in stripping liquor reaches about 160 g/L. The stripping liquor can be used to produce APT of 0 grade of national standards of China.
Key words: tungsten; solvent extraction; quaternary ammonium salt; Na2CO3 system
