Accurate measurement of polarization potentials during electrodeposition of nickel metal from sulphate electrolytes
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Date
Authors
Schoeman, Liezl
Sole, Kathryn C.
Journal Title
Journal ISSN
Volume Title
Publisher
Southern African Institute of Mining and Metallurgy
Abstract
Extraction of nickel from either laterite or sulphide ores involves various
complex hydrometallurgical processes, the final step of which is often
electrowinning to produce pure nickel metal. Methods to investigate,
monitor, and control the electrowinning process are therefore of importance
for producing nickel metal of desirable quality and purity. The significance of
potential measurements during the electrowinning process is well
established. Many potential measurement methods, however, are not
sufficiently accurate or repeatable, and it is therefore often difficult to
monitor and control the electrodeposition process accurately. The
relationship between nucleation (deposition of the first nickel clusters to the
cathode surface) and growth (as more and more nickel clusters deposit)
during electrodeposition is paramount for controlling the formation and
quality of the nickel metal electrodeposit. A need therefore still exists for
accurate measurement of both nucleation and plating overpotentials during
the early stages of electrodeposition. In this investigation, a polarization
measurement technique was developed for nickel electrodeposition from
sulphate electrolytes under typical commercial electrowinning conditions.
This method is repeatable and accurate within approximately 10 mV, and
enables the quick and concise monitoring of both nucleation and plating
during nickel electrodeposition.
Description
This paper
was first presented at the 3rd Young Professionals
Conference, 9–10 March 2017, Innovation Hub,
Pretoria, South Africa.
Keywords
Nickel electrowinning, Polarization potential measurement, Sulphate electrolyte, Galvanodynamic scan
Sustainable Development Goals
Citation
Schoeman, L. & Sole, K.C. 2017, 'Accurate measurement of polarization potentials during electrodeposition of nickel metal from sulphate electrolytes', Journal of the Southern African Institute of Mining and Metallurgy, vol. 117, no. 7, pp. 623-628.