(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 針現(xiàn)行季銨鹽堿性介質(zhì)下萃取鎢工藝存在的再生步驟需消耗氫氧化鈉試劑，并產(chǎn)生不能返回浸出的再生液，從而導(dǎo)致系統(tǒng)中堿和水的不平衡。針對此問題，采用HCO3--CO32-混合型季銨鹽為萃取劑，取消萃取劑再生步驟，對直接從模擬鎢礦蘇打高壓浸出液中萃取鎢進(jìn)行研究。考察溫度、相比、接觸時間和Na2CO3濃度等因素對鎢萃取性能的影響以及雜質(zhì)在萃取過程中的行為，測定有機(jī)相的飽和萃取容量并繪制萃取等溫線，并在此基礎(chǔ)上進(jìn)行模擬串級逆流萃取實驗。結(jié)果表明：采用HCO3--CO32-混合型季銨鹽萃取劑能有效地從鎢礦蘇打浸出液中選擇性萃取鎢；相對于采用CO32-型季銨鹽萃取劑，WO3的萃取率和P、As的去除率雖有所減小，但能省去后續(xù)有機(jī)相再生步驟，實現(xiàn)萃取工序堿和水的平衡；模擬串級逆流萃取實驗結(jié)果表明，經(jīng)9級逆流萃取，WO3的萃取率達(dá)95.64%，P、As的去除率達(dá)90%以上。
關(guān)鍵字: 季銨鹽；鎢；溶劑萃取
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The present technology of extracting tungsten from alkaline solution using quaternary ammonium salt as extractant has problem of disequilibrium of alkali and water because the sodium hydroxide is consumed and regenerated liquid is produced in the regeneration procedure. Aiming at this problem, the direct extraction of tungsten from simulated autoclave-soda leaching liquor was researched in order to shorten the flowsheet and cancel the regeneration process by using mixed quaternary ammonium salt of bicarbonate and carbonate as extractant. The effect of various factors, such as temperature, phase ratio, contact time and Na2CO3 concentration in leaching solution on the extraction of tungsten and the behaviors of impurities in the extraction were investigated. The saturated loading capacity (for WO3) of organic was measured and the extraction isotherm was plotted. On this basis, the simulated counter current extraction was carried out. The results show that the mixed quaternary ammonium salt of bicarbonate and carbonate can selectively extract tungsten effectively from the autoclave-soda leaching liquor of tungsten ore. The regeneration procedure can be cancelled in the new process although both the extraction rate of WO3 and removing rates of P and As are a little lower than those in the process using quaternary ammonium salt of carbonate as extractant. For that, the balance of soda and water in the whole extraction process is realized. The extraction rate of WO3 is 95.64% and the removing rates of P and As are higher than 90% in the 9-stage simulated countercurrent extraction.
Key words: quaternary ammonium; tungsten; solvent extraction
