A validated mathematical model for a zinc electrowinning cell

A set of (95) equations forming a dynamic, nonlinear model of an industrial pilot-plant scale zinc electrowinning cell fed with high purity electrolyte is presented. Only the solution of the steady-state model is considered in this paper. Values for unknown model parameters have either been obtained from the literature or else estimated using experimental data taken from the pilot-plant cell. Sensitivity studies showed that uncertainties in the temperature dependency of the zinc and hydrogen reaction exchange current densities and the exchange coefficient for the hydrogen reaction have a major effect on the model predictions. Excellent agreement between predicted and experimental results was obtained, provided that cathodic mass transfer effects were included in the model. Both parameter estimation and solution of the steady-state model were carried out using the SPEEDUP flowsheeting package.

[1]  S. Trasatti.  Work function, electronegativity, and electrochemical behaviour of metals: III. Electrolytic hydrogen evolution in acid solutions , 1972 .

[2]  L. Janssen,et al.  Mass transfer at gas evolving electrodes , 1985 .

[3]  A. Bard,et al.  The Mechanism of the Zinc(II)‐Zinc Amalgam Electrode Reaction in Alkaline Media As Studied by Chronocoulometric and Voltammetric Techniques , 1972 .

[4]  A. Storck,et al.  Modelling of a continuous parallel plate plug flow electrochemical reactor: electrowinning of copper , 1985 .

[5]  Renato G. Bautista,et al.  Hydrometallurgical Process Fundamentals , 1984 .

[6]  Kenneth S. Pitzer,et al.  Thermodynamics of electrolytes. IV. Activity and osmotic coefficients for mixed electrolytes , 1974 .

[7]  L. Janssen,et al.  Mechanism of bromine evolution at a graphite electrode , 1970 .

[8]  Constantinos C. Pantelides,et al.  SpeedUp—recent advances in process simulation , 1988 .

[9]  D. Mathieu,et al.  Bubble Enhanced Mass Transfer of Electrodeposited Zinc from Acid Solutions , 1985 .

[10]  D. N. Bennion.  Modeling and reactor simulation , 1983 .

[11]  D. J. Pickett.  Electrochemical reactor design , 1977 .

[12]  W. W. Harvey.  Material balance and current efficiency in electrowinning , 1976 .

[13]  M. Whitfield.  The extension of chemical models for sea water to include trace components at 25°C and 1 atm pressure , 1975 .

[14]  Y. Awakura,et al.  Electrical conductivity of acidic sulfate solution , 1987 .

[15]  L. Janssen,et al.  The effect of electrolytically evolved gas bubbles on the thickness of the diffusion layer , 1970 .

[16]  A. C. Scott,et al.  Experimental determination of the factors affecting zinc electrowinning efficiency , 1988 .

[17]  T. Hurlen.  Kinetics of metal/metal-ion electrodes: Iron, copper, zinc , 1962 .

[18]  H. Vogt.  Mass transfer at gas evolving electrodes with superposition of hydrodynamic flow , 1978 .