A kinetic model to describe the nickel electro-recovery from industrial plating effluents under variable electrolyte conductivity

作者：Hernandez Tapia J R; Vazquez Arenas J^*; Gonzalez I

来源：Electrochimica Acta, 2013, 103: 266-274.

DOI：10.1016/j.electacta.2013.04.122

• Nickel electrodeposition
• Recovery
• Modeling
• Kinetics
• Mass-transport
• Electrolyte conductivity

A comprehensive model is developed to account for the kinetics of nickel electro-recovery from industrial plating effluents, typically containing low sulfate (1.25-18.73 mol m(-3)), chloride (0.49-7.41 mol m(-3)) and borates concentrations (9.96-150 mol m-3) at pH 4. The model is developed for linear sweep voltammetry considering the mass-transport of six species in solution under stagnant conditions: Ni2+, NiSO4(aq), H+, Na+, SO42- and Cl-, and accounting for the kinetic discharges of Ni2+, NiSO4(aq), H+ and H2O on the substrate. Additionally, the challenges imposed for the analysis of different baths with variable electrolyte conductivities (397-4202 mu S cm(-1)), migration effects and diffusion coefficients depending on ionic strength (Nernst-Hartley equation), are incorporated into the model to simulate the real conditions of the plating effluents. When only one nickel species (Ni2+) is considered in the model, large deviations are observed between the model and the experimental data at intermediate and high overpotentials of the voltammograms. On the other hand, very good fits are obtained when two nickel species (Ni2+, NiSO4(aq)) are introduced in the model for the experiments conducted at variable electrolyte conductivity. The prediction capabilities of the model are clearly proven by simulating different experimental data generated at constant conductivities, using a single set of kinetic parameters calculated from the fitting stage. The model is developed in a general form such that it can be extended for the robust analysis of other systems or experimental conditions.

• 出版日期2013-7-30