The presence of clays, in particular clay slime, may complicate many mining operations. Clay slime particles may possess a negative or positive charge depending upon the pH in the process and their presence may lead to reduced recoveries in flotation processes. It is assumed that slime particles may adsorb onto the surfaces of the minerals to be floated and by doing so, reducing the efficacy of the flotation chemicals. In this work it is shown that addition of a small amount of dispersant, either a polyacrylic acid or an anionic polyphenolic polymer, increases the recovery of copper and gold, both in laboratory trials and in plant testing of an ore with high clay content. Measurements of adsorption isotherms reveal that the tested dispersants show preferential adsorption towards the clay minerals present, suggesting that the improved recovery upon dispersant addition occurs by prevention of attachment of clay slime particles onto primarily chalcocite but also chalcopyrite.
Seaman, D R, Lauten, R A, Kluck, G and Stoitis, N,
2012. Usage of anionic dispersants to reduce the impact of clay particles in
flotation of copper and gold at the Telfer Mine, in Proceedings 11th AusIMM
Mill Operators’ Conference, pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).