Sericite-chalcocite Particle Sliming Mechanism and Mitigation
Attractive particle interactions which underpin the sliming of gangue mineral particles onto valuable mineral phases are encountered in a number of flotation circuits. Sliming leads to poor flotation recovery of the valuable minerals and high recovery of the gangue particles in the concentrate.To mitigate sliming, low molecular weight poly-electrolytes are commonly used as dispersants during pulp conditioning prior to flotation separation of the valuable and gangue mineral phases. In the present work, the sliming mechanism of sericite onto chalcocite and the influence of interfacial chemistry and two anionic copolymer dispersants (carboxylate substituted polyacrylarnide, polymer Cyquest 3223 and sulfonate substituted polymaleic acid, polymer P80) on the sliming interactions were probed in the pH range 5～9. It was shown that the sliming occurred under solution conditions where both chalcocite and sericite particles were negatively charged, as evidenced by their apparent particle zeta potentials. The suspension pH had a profound effect on sliming process as the extent was markedly greater at lower than higher pH. The sliming was found to be due to the chalcocite dissolution, Cu (Ⅰ) release and oxidation to Cu (Ⅱ), followed by hydrolysis and specific adsorption,leading to sericite particle surface charge reversal and the formation of electropositive sites on chalcocite surface in the pH range 5～9. Addition of polymer Cyquest 3223 or P80 not only increased the magnitude of zeta potentials of both sericite and chalcocite particles but also reduced the formation of Cu (Ⅱ) ions and complexes, which mitigated the sliming behaviour. The adsorption of polymer Cyquest 3223 or P80 at 3 g polymer / kg solid or more had a significant impact on the zeta potentials of both sericite and chalcocite particles. Sericite-chalcocite particulate adsorption studies showed that sliming was completely suppressed via an electro-steric repulsion mechanism resulting from anionic polymeric dispersant adsorption at dosages ＞ 3 g polymer / kg solid.
Chalcocite Sericite, Sliming Dissolution Zeta potential Dispersant
M. Z. He D. Beattie J. Addai-Mensah
Ian Wark Research Institute, University of South Australia, Australia
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
2159-2168
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）