The leaching behaviour of tetrahedrite concentrate in nitrate solution

This paper is concerned with the acid oxidative leaching of tetrahedrite concentrate containing tetrahedrite (Cu,Fe,Zn) 12 Sb 4 S 13 , chalcopyrite CuFeS 2 , pyrite FeS 2 and certain amount of rare metals by using nitrate medium with a solution of 4 M HCl and 3.6 M KNO 3 . During the leaching procedure arising nitrogen oxides are subjected to regeneration in a separated step by oxidation with oxygen or air. Based on the investigation flowsheet of the process has been put forward proceeding a closed-loop cycle, comprising cementation steps for the dissolved metals in the leach liquor and metal recoveries as well sulfur separation from the leach residues.