How Do They Do That? How Copper is Made

Copper ore, in concentrations ranging from 0.29 percent to ten times that amount, is mined from open pit or underground mines

The crushed mine ore is ground in rod and ball mills and then sent to flotation machines where the copper mineral rises to the top in a froth, making a copper concentrate of approximately 30 percent, 27 percent iron and 33 percent sulfur.

In an electrolyte of sulfuric acid, copper sulfate and plating reagents, copper is transferred from an anode at the positive pole of an electric circuit to the cathode at the negative pole. The result is 99.9999 percent pure copper.

The Mine ore is transported to the crushing plant where it is crushed to a size appropriate for the grinding process and then conveyed to the concentrator.

After a series of runs through furnaces, where non-copper elements are burned off or separated, the result is a 99 percent pure molten copper, know as "blister". Blister is poured into anode molds.

While some cathode can be shipped directly to customers, other can be sent to a rod plant, where it is spun into coils of 5/16" diameter continuous cast copper rod.

OXIDE LEACHING AND SOLVENT EXTRACTION-ELECTROWINNING (SX-EW)

Copper oxide ore is piled onto thick high density polyethylene liner (nearly 250 acres in the case of San Manuel). Sprinklers placed on the surface spray a weak acid solution, which dissolves the acid-soluble copper in the ore. The copper bearing solutions are collected and pumped to a solvent extraction plant where an organic extractant removes the copper from the solution. The resulting electrolyte solution is transferred to the electrowinning process where copper is plated out as a cathode.