Procedure for selective copper recovery from tetrahedrite

The complex sulphide mineral tetrahedrite (Cu12Sb4S13) is containing in add ition to copper and antimony many other metal admixtures. Therefore no pyro metallurgical processes have been realised in industrial scale up to now fo r the winning of copper from tetrahedrite raw materials and also hydrometal lurgical methods, which could be an appropriate alternative route are still tested only in various laboratories. The intentions of copper and antimony extraction from tetrahedrite containing raw materials with acid oxidative leaching methods reveal relatively slow leaching rates with low recoveries of copper and antimony in the resulting leach solutions. From the results o f the performed laboratory leaching investigations with tetrahedrite sulphi de concentrates and calcine in acidified ferric chloride medium it appears that copper is leached probably from easily soluble copper (II) sulphate, w hereas antimony is oxidised by roasting into practically insoluble forms. M oreover, antimony is separated from solution due to precipitation in form o f a compound similar to tripuhyite (FeSb2O6) after reaching relatively low concentration of approximately 105 mg/l in the leach liquor. Since the diss olved copper can be concentrated in the resulting solutions, these facts co uld provide besides favourable extraction results a possibility of copper s eparation from antimony.