A method of recovering copper from a copper sulfide concentrate comprising a copper arsenic sulfosalt or a copper antimony sulfosalt, using carbon as a catalyst. The concentrate and carbon are added to an acidic sulfate leach solution. The copper is leached from the concentrate, in the presence of an oxygen-containing gas. The operating potential is maintained above a selected level. The carbon copper sulfide ratio of the carbon being added to the copper sulfide present in the concentrate being added is at least 1:20. The carbon may be maintained above a selected concentration in the leach solution. The leached copper is recovered from the solution by conventional methods.