Mechano-chemical leaching in hydrometallurgy of complex sulphides

This study evaluates the efficiency of chemical leaching of complex antimony and arsenic sulphides (tetrahedrite, jamesonite, enargite) in alkaline Na2S solution following mechanical activation in a laboratory planetary mill and attritor, respectively. Antimony and arsenic are extracted into the leach liquor and the copper or lead-containing solid residues can be exploited in pyrometallurgy. The mechano-chemical leaching of tetrahedrite concentrate was performed in an industrial attritor in a process called MELT and compared with the conventional chemical leaching of mechanically activated tetrahedrite. The MELT process leaches antimony several times faster, under similar conditions, than the industry tested hydrometallurgical SUNSHINE process which does not apply milling.