To overcome the challenge of selective gallium (Ga) recovery from Bayer mother liquor with low Ga,complex impurities,and strong alkalinity,a synergistic route—amidoxime-functionalized chelating resin adsorption-HCl elution-tributyl phosphate (TBP) extraction-water stripping—was developed,enabling selective separation and enrichment in strongly alkaline media.The optimal adsorption was at 65℃,L/S=5∶1,2 h,achieving 84.7% Ga uptake;the process follows a pseudo-second-order kinetic model (chemisorption-controlled) and the Langmuir isotherm (monolayer).Elution with 3 mol/L HCl at L/S=10∶1 achieved complete desorption within 40 min.After adjusting eluate to 4 mol/L HCl,single-stage extraction with 20% TBP/kerosene at oil-to-aqueous ratio O/A=1∶1 reached 100% extraction;water stripping (O/A=1∶1) gave 92.47% per stage,and two stages yielded >99% recovery.Mechanistically,TBP forms GaCl3·3TBP with Ga(Ⅲ) in high-chloride media;hydration dissociates the complex during stripping,transferring Ga to the aqueous phase and regenerating TBP.This process provides data and theoretical support for green,efficient Ga recovery from Bayer liquor.
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