Direct enrichment of zinc(II) from and into ammoniacal media with commercialLIX84I

Abstract

Abstract Solvent extraction of zinc(II) from and into ammoniacal media has been investigated using commercial LIX84I extractant. The effects of aqueous solution pH, total ammonia concentration and temperature on extraction of zinc(II)and ammonia stripping of loaded organic phases were examined. The extraction and stripping behaviors of zinc was also compared in the absence and presence of tributyl phosphate (TBP). The results indicate that LIX84I presents a good potential for zinc extraction in the ammonical solution. However, TBP has an antagonistic effect on zinc extraction with LIX84I. The extraction behavior of Zn(II) presents a special swing phenomenon in the both cases with and without TBP. The slope analysis and IR spectra indicate that each zinc ion can coordinate with two LIX84I molecules, whereas TBP molecules could bond with the LIX84I molecules, thus depressing zinc extraction. The zinc loaded organic phases can be effectively stripped with the ammoniacal media, especially increasing the ammonia concentration. Zinc stripping is more easy for the mixed system with TBP than the individual LIX84I system. Moreover, the extraction of zinc is an exothermic process, whereas the ammonia stripping of zinc is an endothermic process. The extraction and stripping isotherms indicate that the direct enrichment of zinc(II) from and into ammoniacal media can be achieved with the commercial LIX84I. These results are helpful for the hydrometallurgical recovery of zinc from the non-traditional resources.