Selective extraction of zinc from sulfate leach solution of zinc ore

1　INTRODUCTIONSolventextractionwasregardedasahighlyeffi cienttechniqueofseparationandpurification .Ithasbeenwidelyappliedinmetalextractionandrecoveryduringhydrometallurgicalprocessandenvironmentalprotection[14 ] .Solventextractionhasbeencommer ciallyusedintheextractionofuranium ,rarenoblemetals ,copper ,cobaltandnickel,whichwastypical lypresentedbythetechniqueofleach solventextrac tion electrowinning .Presently ,thecopperproductionfromsolventextractionhasbeenaccountedformorethan 2 0 %oft…

Selective extraction of zinc from sulfate leach solution of zinc ore

Selective extraction of zinc from sulfate leach solution of zinc ore was studied. D2EHPA dissolved in 260~#kerosene was used as extractant. The pH-extraction isotherms show the extraction order of D2EHPA for metals is Fe~(3+)>Zn~(2+)>Ca~(2+)>Al~(3+)>Mn~(2+)>Cu~(2+)>Cd~(2+)>Co~(2+)>Ni~(2+)>Mg~(2+)(pH_(0.5)). This confirms that Fe~(3+) is preferentially extracted before the extraction of zinc. Extraction experiments were carried out with varying the extractant content, equilibration time, aqueous pH and phase ratio, and the solvent extraction of zinc with sodium salt of D2EHPA were also investigated. Some impurity co-extracted into the zinc loaded organic phase was efficiently removed by scrub, and the Fe~(3+) was hardly stripped from organic phase by sulfuric acid, hence zinc was separated from Fe~(3+) by selective stripping. A pregnant zinc sulfate solution with low contaminants was obtained by selective solvent extraction.