Abstract
The effect of electrode oscillation on the rate of diffusion-controlled anodic processes such as electropolishing and electrochemical machining was studied by measuring the limiting current of the anodic dissolution of a vertical copper cylinder in phosphoric acid. Parameters studied were frequency and amplitude of oscillation, and phosphoric acid concentration. Within the present range of conditions, electrode oscillation was found to enhance the rate of anodic dissolution up to a maximum of 7.17 depending on the operating conditions. The mass transfer coefficient of the dissolution of the oscillating vertical copper cylinder in H3PO4 was correlated to other parameters by the equation: Sh = 0.316Sc(0 33)Re(nu)(0 64).
The importance of the present study for increasing the rate of production in electropolishing and electrochemical machining, and other electrometallurgical processes limited by anode passivity due to salt formation such as electrorefining of metals was highlighted. (c) 2013 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.