Recovery of gold from aqueous solutions

Abstract

Gold is recovered from aqueous solutions which include a solubilizing reagent by contacting the solution with hydrogen under selected conditions until the gold precipitates, and removing the precipitate from the solution. The reagent comprises a thiourea or a thiosulfate and the solution is a leach, eluate or strip solution. The contacting may be by gas sparging or under hydrogen pressures, e.g. up to about 300 psi, and usually the temperature is within about 20.degree. to 170.degree. C. If the initial feed solution is too dilute, it can be concentrated by ion exchange or solvent extraction followed by elution or stripping respectively. Any silver present is precipitated with the gold.

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