Remove Impurities from Metal

Electrowinning is a widely used technology in modern metal recovery, mining, refining and wastewater treatment applications.

Electrowinning, also known as electroextraction, is a tradition electrodeposition of metals from their ores that have been put in solution or liquified to recover waste metals through the rinse system while reducing waste water generation and chemical discharge. Due to the relative value of gold, silver, copper, cadmium and zinc, it is an extensively employed method in modern metal recovery, mining, refining and wastewater treatment applications. Electrorefining and electroplating both employ large-scale electroplating to remove impurities from metals, and both are key procedures for the cost-effective and simple purification of non-ferrous metals.

A tank, rectifier and pump make up a traditional electrowinning unit. Inside the tank, cathodes and anodes are aligned, and the pump fills the tank with electrolytic solution. The rectifier provides electrical current to cathodes and anodes in such a way that the difference in electrical potential causes cations to migrate towards the cathode. Positively charged ions will plate on the cathodes over time. It’s vital to remember that when metal accumulates on the cathode, the amount of metal deposited in solution decreases, and plating slows. The cathodes with pure metal deposited will be harvested once the metal deposition rate reaches a level that is insufficient for electroplating. In the case of waste water treatment, the solution (waste water) will be cleansed or significantly purified of non-ferrous metals and then chemically precipitated or reused in the industrial process.

Our Revolutionary Electrowinning Rotacat

Trionetics’ revolutionary rotating cathode cell allows for the quick recovery of metals in nugget form for reclamation or reuse from concentrated process streams. High yield and low overall operating costs are achieved by using rotating cathodes and turbulent solution flow through clean seed media. Because plating efficiency drop at around 0.5 ppm with revolving cathodes, plating down to discharge limits is not possible. Ion exchange regenerant can be treated and reused multiple times, which is a common application. The revolving cathode barrel can be changed with a high-efficiency cathode (mailbox) if necessary, allowing plating to discharge limitations.