Measurement of electrochemical potentials in flotation systems

CIM Bulletin, Vol. 81, No. 920, 1988

G. LABONTE and J.A. FINCH, Department of Mining and Metallurgical Engineering McGill University, Montreal

A long-standing objective has been to obtain interpretable measurements of the oxidation-reduction potential in mineral slurries. For this purpose several sensing electrodes (black platinum wire, platinum foil and spiral, gold foil and spiral, and sulphide minerals such as chalcopyrite and galena) were investigated to determine their response to the presence of sulphide minerals in the pulp, and to the addition of reagents commonly used in flotation. The observed discrepancies between the electrodes may be explained using a combination of the classical mixed potential model for complex solutions and the probability of contact between the mineral particles and the sensing electrode. It is shown from laboratory testwork that gold spirals are preferred over platinum electrodes. Finally, some of the practical aspects of using the electrochemical measurements in a plant environment are discussed.

Keywords: Mineral processing, Flotation systems, Electrochemical measurements.