Electrochemical Machining Recycling for Metal Recovery and Waste Elimination

This paper will discuss an integrated technology being developed by Faraday to recover and recycle metals from electrochemical machining (ECM) electrolytes. ECM is suited for low mass removal, high value-added manufacturing steps that cannot be easily performed using conventional machining, whether due to workpiece material properties, tooling limitations, or high surface integrity requirements. Sludge byproducts formed during conventional ECM processes are difficult and expensive to recycle, and discarding the sludge results in the loss of potentially valuable “waste” metal as well as entrained electrolyte. The FARADAYIC^® Recycling ECM [(R) ECM] technology machines metals into the electrolyte to a concentration of 800–1500 ppm (mg L⁻¹), and subsequently recovers those metals by electrowinning in solid/metallic form devoid of hydroxides/hydrated oxides, without intermediate electrolyte processing.