Aqueous solutions containing metal cations, that may include cations of both desired metal and impurity or secondary metal, are treated with an organic liquid extractant suitable for the extraction of cations of the desired metal, cations of at least one secondary metal being co-extracted. After phase disengagement, the loaded organic phase containing cations of either a desired metal or desired metal together with at least one secondary metal is contacted with a solid metal or solid metal alloy capable of reducing in the organic phase cations of either a desired metal or a secondary metal from a higher to a lower state of oxidation. Depending on the extracted metal(s) and the added solid metal or alloy, cations of the at least one extracted metal are reduced to the lower state of oxidation and either are deposited (cemented) in the metallic state onto the solid metal or alloy, or are partially reduced in the organic phase to a lower, oxidation state with the solid metal or alloy being oxidized in part. The method of galvanic stripping is carried out at ambient pressures and at ambient or slightly elevated temperatures.
T. J. O'Keefe, "Method for Stripping Metals in Solvent Extraction," U.S. Patents, Jul 1993.
Materials Science and Engineering
Patent Application Number
© 1993 The Curators of the University of Missouri, All rights reserved.
20 Jul 1993