In one aspect, the invention provides processes for producing an enriched copper concentrate from a copper-and-nickel-containing ore. Processes of the invention may include an initial step of comminuting the ore, to provide a ground ore comprising copper minerals and nickel minerals. The ground ore may be subjected to a floatation process, to separate the ground ore into distinct fractions, such as first and second concentrates. A first concentrate may for example be made up of copper-enriched-and-nickel-containing solids, while a second concentrate is made up of nickel-enriched-and-copper-containing solids. The floatation process may for example fractionate the ore so that the concentration of copper minerals is higher in the first concentrate than in the ore, and the concentration of the nickel minerals is higher in the second concentrate than the ore.