2-DIMENSIONAL CURRENT DISTRIBUTION, MASS-TRANSFER, AND METAL RECOVERYIN PACKED-BED ELECTRODES

Two-dimensional current and potential distributions in a flow-by packe d bed electrode have been measured with the test solution of CuSO4/Na2 SO4. A mathematical model describing a rectangular flow-by packed bed electrode below limiting currents has been developed. Comparisons of c urrent and potential distributions between the simulated and experimen tal results have been made, and fairly good agreements with each other have been reached. A mass transfer correlation has been obtained from limiting - current measurements, and it can be expressed as follows j (D) = 1.864 Re-p(-0.59) 10 < Re-p < 140 The performance of metal recov ery by packed bed electrodes in circulating operation has been studied , and the concentration of cupric ion was reduced from 900 ppm to belo w 3 ppm. The experimental concentration-time curves are well predicted from the numerical results of the mathematical model.