Water-soluble copper sulfate and related salts can be recovered from ground water seepage in caverns and mines. Weathered copper sulfide minerals evolve to sulfates which are dispersed in ore near the earth's surface. Mined sulfide ore can weather slowly above ground to sulfate.Heap leaching, heap roasting/leaching are large scale activities to recover copper by a solubilization route. Copper can be recovered from water solutions by displacement using iron. The product is a metal which can be of high purity. Copper sulfate can also be used directly in carbon reduction smelting operations. Experimental results show that iron in the forms of steel and various cast irons can serve in the displacement reactions although the rates of metal recovery and the character of the copper deposits vary. The experiments are related to copper production in China from the 12th century. -- AATA