Solvent Extraction Electrowinning (SXEW) is a hydrometallurgy technology used to extract metals by dissolving the metals in an acid solution. SXEW has been used to extract copper from oxide copper ore for over 30 years and accounts for about 20% of annual copper production. The Skorpion Mine located in Namibia, Africa is the first, and to date the only, mine in the world using SXEW to extract zinc from oxide zinc ore.

The ore is crushed and ground, then transported to leach tanks where it is mixed with a weak sulfuric acid solution, which dissolves zinc and other soluble metals. The material is then filtered separating the solids from the metal bearing solution, the leach solution. The leach solution is mixed with an organic extraction solution, which selectively removes and concentrates zinc from the pregnant leach solution into the organic extraction solution. The spent leach solution is recycled back to the leach circuit. The organic extraction solution is then mixed with a strong sulfuric acid solution, the electrolyte solution, which removes the zinc from the organic extraction solution. The spent organic extraction solution is recycled back to the extraction circuit. The electrolyte solution is taken to electrolytic cells and the zinc reduced to SHG zinc (99.995% zinc), the refined product.

Reunion Mining plc in conjunction with Tecnicas Reunidas developed solvent extraction electrowinning for the oxide zinc mineralization at the Skorpion deposit and completed a feasibility study for the deposit. Anglo American purchased Reunion Ltd. acquiring 100% of the project. Anglo performed a second feasibility study and constructed the mine, SXEW plant and electrowinning refinery, bringing the deposit to production in May of 2003. Skorpion ramped up to full production in 2004 at about 150,000 metric tons of Super High Grade (SHG, 99.995%) zinc per annum.