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微乳液提取铝酸钠溶液中钒的工艺研究
【作者】 朱志全;
【导师】 陈金清;
【作者基本信息】 江西理工大学 , 有色金属冶金, 2010, 硕士
【摘要】 本文论述了铝酸钠溶液体系中,微乳液法萃取钒的机理,考察了N263/异戊醇/煤油/氢氧化钠溶液反胶束微乳液体系对铝钒的分离效果,并逐一量化影响因素,N263浓度、助表面活性剂异戊醇浓度、内水相碱浓度、水乳比R、料液碱度、萃取温度、搅拌强度和萃取时间。通过正交实验得到最佳萃取工艺条件。萃取后的微乳液中含有铝杂质,实验通过洗涤工艺除铝,考察了萃洗液成分浓度、相比、洗涤温度、搅拌强度、洗涤温度、洗涤时间因素对铝洗脱率的影响,确定了最佳洗涤工艺。同时还对富钒微乳液进行了破乳反萃研究,通过单因素优选法确定了破乳和反萃的最佳工艺条件。结果表明:在萃取试验中,当含钒铝酸钠料液成分为Al2O3浓度为20.4g/L、Na2O浓度为14.88g/L、V2O5为1g/L时,正交试验得出微乳液萃取提钒的最佳工艺为:表面活性剂N263浓度为10%、助表面活性剂异戊醇浓度为20%,水乳比为3、内水相氢氧化钠浓度为0.4mol/L,萃取时间为3min、搅拌强度为200r/min、萃取温度为50℃,钒的萃取率达到了85%,钒铝的分离系数为65,萃取后微乳液中V2O5的浓度为2.560g/L、Al2O3的浓度为1.642g/L。在洗涤试验中,得到的洗涤铝的最佳工艺条件是:萃洗液为4g/L NaOH和3g/L V2O5、微乳液与萃洗液体积比为3、洗涤时间为6min、搅拌强度为200r/min、洗涤温度为40℃、铝的洗涤率达到了99.5%,洗涤后水相中Al2O3的浓度为4.9g/L,V2O5的浓度为0.645g/L,可以直接回萃取阶段重新萃取,洗涤后微乳液中Al2O3的浓度8mg/L,V2O5的浓度为3.450g/L。在反萃试验中,得出的反萃和破乳最佳工艺条件是:反萃剂为1.0mol/L NaOH+0.6mol/L NaCl,反萃时间为3min,反萃温度为60℃,微乳液与反萃液体积比为6。反萃得到的反萃液中V2O5的浓度为20.7g/L,Al2O3的浓度为36mg/L。
【Abstract】 The principle of microemulsion solution extracting vanadium from sodium aluminate solution was discussed in this paper. In microemulsion solution system of N263- isoamyl alcohol- kerosene-sodium hydroxide, the effects of many factors, such as the concentration of N263, the concentration of cosurfactant isoamyl alcohol, the concentration of alkali in internat water phase, the volume ratio of aqueous to microemulsion(R), the concentration of alkali of feed liquid, temperature, agitation intensity and extraction time, on the separation of aluminium and vanadium, were explored, and optimum conditions were obtained by orthogonal experiment method. The microemulsion after extraction contains impurity of aluminum, which was removed through abstersion. The effects of the concentration of extract component, ratio of microemulsion to the water volume, temperature, agitation intensity and abstersion time on the aluminum removal was studied and the optimum conditions were obtained. And the back extraction vanadium from vanadium-riched microemulsion was also explored and the optimum conditions were ascertioned through single factor selecting method.The results as follows:In extraction experiments, on conditions that the concentration of Al2O3, Na2O and V2O5 were 20.4g/L, 14.88g/Land 1g/L respectively in sodium-aluminate-vanadate solution, the optimum conditions were as follows: the concentration of surfactant N263 and cosurfactant isoamyl alcohol were 10% and 20% respectively, the volume ratio of aqueous to microemulsion(R) was 3, the concentration of alkali in internat water phase is 0.4mol/L, extraction time was 5 minutes, agitation intensity was 200 r/min and the temperature was 50℃. The extraction rate of vanadium reached 85%, and the separation coefficient of vanadium and aluminum was 62. The concentration of vanadium and Al2O3 in organic phase after extration were 2.560 g/L and 1.642 g/L respectively.In abstersion experiments, the optimum conditions of removing aluminum were as follows: the extraction wash solution contained 4g/L NaOH and 3 g/L V2O5, the volume ratio of microemulsion and wash solution was 3, time was 6 minutes, agitation intensity was 200 r/min and the temperature was 40℃. The aluminum abstersion rate reached 99.5%. The concentration of Al2O3 and V2O5 after abstersion were 4.9g/L and 0.645g/L respectively in aqueous phase, which can be returned to re-extraction in the process of extration. And contrastively the concentration of Al2O3 and V2O5 after abstersion were 8 mg/L and 3.450 g/L respectively in microemulsion.In back-extraction experiments, the optimum conditions of back-extract vanadium were as follows: back-extraction solvent was consisted by 1.0mol/LNaOH and 0.6mol/LNaCl, back-extraction time was 3min,temperature was 60℃, the volume ratio of microemulsion to back-extraction solution was 6. The concentration of Al2O3 and V2O5 were 36mg/L and 20.7g/L respectively in back-extraction solution.
【Key words】 microemulsion; extraction; back-extraction; aluminum; vanadium;