Abstract: A process for electrowinning of copper from leach solutions containing a high concentration of iron in the range of about 5 to 40 gpl, is disclosed. The process consists in applying direct current through the solution and periodically reversing the polarity of such current to obtain a solution having a low ferric ion concentration, thereby increasing the operating current efficiency and consequently decreasing the power consumption.

Abstract: A fluidized bed electrode system comprises an electrode chamber having a porous base, a main electrode consisting of a bed of fine solid particles contained in such chamber and selected from the group consisting of metals, metal coated glass beads and metal coated plastic beads, a current feeder extending into the bed, means for leading air or inert gas through the porous base at a predetermined velocity and pressure to fluidize the bed, and means for introducing a solution to be treated into the electrode chamber at a point above the porous base and for circulating such solution through the bed at a predetermined flow rate.