Experimental Study on Iron Removal by Precipitation and Vanadium Extraction by Aqueous Two-Phase System from Red Mud Acid Leachate AITranslate

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Chinese Library Classification Number:X758[环境科学与工程—环境工程]

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To address the emulsification risk during aqueous two-phase extraction caused by high iron con-centration(Fe³⁺>5 g/L)in the acidic leachate of red mud,the jarosite method was employed for selective iron removal.Pretreatment of 100 mL acidic leachate via potassium sulfate precipitation was conducted.Under the optimized conditions(precipitation time of 60 min,precipitation temperature of 100℃,leachate pH of 2,and K2SO4 seed crystal addition of 3.5 g),an iron precipitation rate of 53.19%is achieved.The Fe³⁺concentration in the filtrate is effectively reduced to below 5 g/L,eliminating the emulsification risk.Subsequently,an aqueous two-phase system(ATPS)composed of polyethylene glycol 2000(PEG2000)and sodium sulfate was constructed to extract vanadium from the iron-removed solution.The effects of ex-traction time,iron-removed solution pH,charge regulator AC1815,and extraction temperature on vanadium extraction rate were systematically investigated.The extraction mechanism was explored through FTIR spectroscopy and Zeta potential.The results indicate that apart from Fe³⁺,coexisting ions exhibit negligible interference with vanadium extraction.Under the optimal conditions of an extraction time of 20 min,an iron-removed solution pH of 2,an extraction temperature of 20℃,and the addition of one drop of AC1815,the vanadium extraction rate reaches 85.24%.The protonated charge regulator combines with polyvanada-te anions through electrostatic attraction,thereby driving their transfer into the PEG2000 phase.This process successfully achieves vanadium-iron separation in the acidic leachate of red mud and efficient vana-dium extraction in the ATPS,providing theoretical support and a technical pathway for the industrial re-source utilization of red mud.