Copper Cathode Electrowinning Plant Electrolytic Cell

1. leaching
Heap Leaching: Crushed ore is piled up in heaps, and a leaching solution, usually sulfuric acid, is applied over the heap. The solution percolates through the heap, dissolving the copper from the ore as it moves downward.

Agitation Leaching: In some cases, the ore is placed in tanks, and the leaching solution is agitated to improve contact between the solution and the ore. This method is faster but requires more controlled conditions.

2. Solvent extraction
The copper-laden leach solution, called pregnant leach solution (PLS), is then subjected to solvent extraction. In this process, an organic solvent selectively binds with the copper ions, separating them from other impurities in the solution.

The copper is transferred from the aqueous phase to the organic phase. The remaining solution, called raffinate, is often recycled back to the leaching stage.

3. Electrowinning (EW)

The copper-rich organic solution is then mixed with an aqueous solution in a stripping stage, where copper ions are transferred back into an aqueous phase called the electrolyte.

In the electrowinning process, an electric current is passed through the electrolyte in an electrochemical cell. Copper ions are reduced and deposited onto stainless steel or copper starter sheets, forming high-purity copper cathodes.

4. Cathode Harvesting

The copper cathodes, which are typically 99.99% pure, are periodically harvested from the electrowinning cells. The sheets are removed, washed, and prepared for sale or further processing.