REFINING OF FERROUS AND BASE METAL SULPHIDE ORES AND CONCENTRATES

摘要

The invention provides a process for extracting a base metal from a base metal bearing ore or concentrate which includes forming a slurry of the ore or concentrate with an electrolyte containing chloride ions and copper ions, oxygenating the mixture and maintaining the pH of the mixture from 1.5 to 7.0. Iron impurities will be substantially precipitated as ferric oxide and may be recovered, sulphide sulphur will be converted to elemental form and can be recovered and the base metal is taken into solution. The base metal can be recovered by electrolysis which can also produce hydrogen ions for pH maintenance. The copper ions can be precipitated by the addition of fresh ore or concentrate and can be recycled. The process is preferably carried out in a counter-current manner in which electrolyte containing increasing amounts of the base metal in solution is conveyed counter-current to solids which decrease in base metal content. The process is particularly applicable to lead, zinc or leadzinc ores or concentrates.