Electrodeposition of Metals in Fluidized Bed Electrodes: Part I . Mathematical Model

Abstract

A mathematical model is presented to describe the behavior of fluidized bed cathodes when employed in the electrodeposition of metals from solution. Principal results are the effect of electrode and electrolyte resistivity on cell voltage, power consumption, operability, and bed effectiveness. The model applies to a multicomponent electrolyte and allows for the presence of oxid izin.g agents in the electrolyte. Computed results also include current efficleneles.* Electrochemical Society Active Member. 1 Present address: AMAX, Incorporated, Golden, Colorado 80401. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.89.24.43 Downloaded on 2014-10-12 to IP VoI. 126, No. 7 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.89.24.43ABSTRACT A laboratory scale cell equipped with a fluidized cathode was employed to electrodeposit copper from aciQified copper sulfate solution. Copper concentrations in the electrolyte were in the 0-20 g/liter range while the electrolyte was acidified with approximately i00 g/nter of sulfuric acid. Superficial current densities were in the range 200-600 A/ft 2. Current efficiency power consumption per pound of copper deposited and operability were determined as a function of copper concentration, particle size, bed expansion, superficial current density, and acid concentration. The results were compared with the predictions of mathematical models.

Experimental Study of Silver Cathode for Electrochemical Deoxygenation of Seawater for Enhanced Oil Recovery

“…The higher oxygen removal can be explained by the fact that the resistivity decreases with the increase of the electrolyte concentration. A study by Sabacky and Evans 27 showed that efficiency and power consumption in a porous electrode cell depends also on the resistivity of the electrolyte and predicted inefficient utilization of bed surface at high electrolyte resistivity.…”

Copper recovery in a spouted vessel electrolytic reactor (SBER)

“…As already indicated, anodic zones can form in the moving bed cathode if the current density is not sufficiently high. Sabacky and Evans [36] were among the first to introduce the concept of an effectiveness factor in a fluidized bed electrode as the ratio of total deposition rate to the rate when bed and electrolyte exhibit zero resistance. Similarly, Scott [37] defined an effectiveness factor in a particulate bed as the fraction of electrode area that effectively contributes to electrodeposition.…”

Electrical and Electrochemical Behavior of Fluidized Bed Electrodes: I . Potential Transients and Time‐Averaged Values

“…16 where the variation of the timeaveraged overpotential with position is displayed. Theoretical models for porous electrodes, e.g., that of Newman and Tobias (15), and_for fluidized bed electrodes, e.g., that of Sabacky and Evans (16), have predicted the corresponding U-shaped distribution of local reaction rate. Experimental confirmation of this variation of deposition rate (in copper electrodeposition experiments) with an inactive zone in the middle of the bed has been provided by Masterson and Evans (17).…”