METHOD FOR RECOVERY OF SILVER FROM SULPHUR-CONTAINING ZINC LEACH RESIDUES

摘要

The invention relates to a method of recovering silver and a method of controlling a leaching process for recovering silver from a direct zinc leach residue, an apparatus for recovering silver from a direct zinc leach residue, a control system for implementing the control method, and a computer program. The method comprising the steps of: 1) a silver leaching step, wherein the direct zinc leach residue is subjected to oxidative chloride leaching, having the following conditions: 1) chloride concentration of the leach solution in the range of 25-70 g/l ii) pH of the leach solution in the range 1.6 - 2.6 iii) redox potential of less than 460 mV (Pt vs. Ag/AgCI) 2) a silver recovery step, wherein silver is recovered from the silver containing leach solution.