An opportunity for improvements in efficiency
A large fraction of present-day production of copper is by the hydrometallurgical technology of leaching-solvent extraction-electrowinning. While competitive with the more traditional pyrometallurgical route, this hydrometallurgical route consumes considerable amounts of electrical energy in the electrowinning step where copper is deposited from an aqueous solution using a DC current. It has been usual to use lead alloy anodes in the electrowinning cells. However, recently alternative anodes have been used; these consist of a titanium structure with a platinum-group oxide coating that is catalytic for oxygen evolution (the anodic reaction in electrowinning). Although more expensive than a lead anode of comparable size, these newer anodes reduce the cell voltage and thereby its energy consumption.
The Wireless Industrial Technologies Approach
In order to maintain the superior performance of these anodes and to avoid low current efficiency (passage of current without the deposition of the maximum amount of copper) it is advisable to monitor the current passing through each anode. In this way, for example, damaging shorts between anode and cathode can be detected so that operators can correct them. WIT is working with a major copper producer on the development of a wireless monitor of anode currents. Being wireless enables the hardware to avoid the corrosion that would otherwise result from the acidic hostile environment in and around the cells.