论文部分内容阅读
A novel mixer-settler-mixer three chamber integrated extractor has been proposed for performing liquid-liquid-liquid three phase continuous extraction and separation of Li,B,and Mg from salt-lake brines [1].The three-liquid-phase system forming in settler consists of an organic solvent-rich top phase,tributyl phosphate (TBP) in kerosene,a polyethylene glycol (PEG)-rich middle phase and a (NH4)2SO4-rich aqueous bottom phase [2-4].Various influences from flux of three liquid phases,stirring speed,phase ratios,aqueous solution pH values,molar ratios of Fe/Li and Mg/Li,initial Cl- concentrations,added amounts of (NH4)2SO4 and PEG2000,volume percentage of TBP on three-liquid-phase partitioning of Li,B,and Mg were investigated.Experimental results indicate that Li and B can be enriched into the top organic phase and middle PEG phase,respectively,while most of Mg remain in bottom aqueous phase.The present work highlights a feasible apparatus to perform continuous three-liquid-phase extraction.The results are important for future industrial application of the proposed three-liquid-phase extraction technique to recover Li and B values from salt-lake brines in west China.