A method and device for depleting copper smelting slag. The method comprises mixing copper smelting molten slag (1) with a reductant (2) and an inert gas (3) under pressure, and then depleting same. The device for depletion comprises a furnace body (4), which furnace body (4) is provided with a feed opening (413) and a slag discharge port (416), and gas nozzles (411) disposed on the side wall of the furnace body.

A process for recovering copper from heap leach residues, the process comprising treating heap leach residues to provide treated heap leach residues providing improved permeability of a heap of the treated heap leach residues, and leaching the heap of the treated heap leach residues with a leaching solution. Treating the heap leach residues includes: a) blending the heap leach residues with additional material to provide a blend; or b) agglomerating the heap leach residues; or c) both blending the heap leach residues with additional material and agglomerating.

A method of leaching a gold/copper-containing sulfidic mined material that includes two leach stages, with a gold leach stage leaching gold from the material with a gold leach liquor and a copper leach stage leaching copper from the material with a copper leach liquor.