Fremgangsmåte for å hindre dannelse av jarositt og ammonium- og alkalibaserte dobbeltsalter i opplösningsekstraksjon ved sure utvaskingsprosesser

摘要

The present invention relates to a method for preventing the formation of jarosite and ammonium- and alkali-based double salts in the solvent extraction of acidic extraction processes. The organic extraction solution is neutralized by ammonium or alkali salts prior to the separation of valuable metals in order to improve the extraction recovery. In a pre-extraction step after the neutralization, the extraction agent is contacted with an aqueous solution containing a metal which replaces the ammonium or alkali ions contained in the extraction solution. Thus the ammonium or alkali ions are removed from the extraction circuit prior to separation of the valuable metals by extraction.