Electrowinning, also known as electroextraction, is the electrodeposition of metals from their ores after they have been dissolved in water by a process known as leaching. A new electrodeposition technology is cyclone electrodeposition, which has an obvious technical advantage in multi-metal purification and separation.

It is commonly used to extract low concentrations of copper, gold, silver, cobalt, nickel, zinc and so on, in an acidic solution, including sulfuric acid, hydrochloric acid, nitric acid and cyanide. Cyclone electrodeposition avoids the concentration polarization caused by the slow flow of an electrolyte, because of the relatively high-speed motion of the electrolyte and electrode.

In the traditional electrodeposition process, the thickness of the diffusion layer reduces, and enhances the mass transfer while minimizing an ion exchange. Electrowinning has been known for more than 200 years, and its use in the production of copper has increased dramatically in recent years. Anodes and cathodes are submerged in a solution containing metal ions in traditional electrowinning. Metal ions are reduced and deposited on the cathode, but this causes ions in the surrounding solution to deplete, slowing mass movement and deposition. As a result, extracting
the majority of the metal from the solution is difficult, especially when the metal ion concentration is low. 

Turbulence in the medium is an important approach to increase mass transmission. Cyclones maintain a turbulent flow, allowing for rapid mass transfer. Traditional electrowinning requires recirculating the treated solution for further processing, but cyclone electrowinning technology is a straightforward, one step approach for treating metal ion solutions. The capacity to apply substantially larger current densities due to highly efficient mass transfer is a key benefit of cyclone electrowinning technology. Higher current densities result in a significant rise in the cathode production rate per square meter and cheaper capital expenses.