A distributed, easily controllable electrode may be constructed by using a fluidized bed of metallic particles. Such electrodes are currently under investigation, particularly with regard to electrochemical metal extraction. The control of particular reactions through fluidization is difficult, as exemplified by the copper extraction case referred to, since the effect of electrode expansion is highly nonlinear. The essential features of a control scheme are outlined, a controller to regulate over-potential by electrolyte flow feedback is constructed, and results presented for different controller parameters.