Dissolution of copper and iron from sulfide concentrates in cupric chloride solution

In this study the leaching behavior of copper and iron in cupric chloride solution was studied. These metals were present in minerals of sulfide concentrates, such as chalcopyrite, bornite, covellite, pyrite, hematite and magnetite. Chemical and mineralogical composition of the concentrates was determined. Sulfide concentrates were leached for 2 h under non-oxidative conditions, similar to those used in the first leaching stage of HydroCopper® process. It was shown that copper in bornite was the most active to dissolve in the studied environment. Over 85% of copper in chalcopyrite could be leached when present with other secondary copper sulfides. When copper was carried by chalcopyrite–pyrite type concentrate, 64% of copper could be leached. Iron in the solution originated from secondary copper minerals, since pyrite, hematite and magnetite were shown not to dissolve in the studied environment.

► Detailed chemical and mineralogical analysis of five sulfide concentrates.
► Over 85% of copper dissolved from chalcopyrite when present with secondary sulfides.
► When present with pyrite less chalcopyrite could be dissolved.
► Iron in pyrite, hematite and magnetite did not dissolve in the studied environment.
► There was selective dissolution of iron or back precipitation of copper.