Selective extraction of zinc from sulfate
leach solution of zinc ore
leach solution of zinc ore
(School of Minerals Processing and Bioengineering,
Central South University, Changsha 410083, China)
Central South University, Changsha 410083, China)
Abstract: 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
Fe3+＞Zn2+＞Ca2+＞Al3+＞Mn2+＞Cu2+＞Cd2+＞Co2+＞Ni2+＞Mg2+(pH0.5). This confirms that Fe3+ 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 Fe3+ was hardly stripped from organic phase by sulfuric acid, hence zinc was separated from Fe3+ by selective stripping. A pregnant zinc sulfate solution with low contaminants was obtained by selective solvent extraction.
Fe3+＞Zn2+＞Ca2+＞Al3+＞Mn2+＞Cu2+＞Cd2+＞Co2+＞Ni2+＞Mg2+(pH0.5). This confirms that Fe3+ 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 Fe3+ was hardly stripped from organic phase by sulfuric acid, hence zinc was separated from Fe3+ by selective stripping. A pregnant zinc sulfate solution with low contaminants was obtained by selective solvent extraction.
Key words: solvent extraction; zinc; stripping; D2EHPA