Effect of aluminum ions on the adsorption of carboxymethyl cellulose onto talc

Abstract

Talc is a gangue mineral of many sulfide minerals, which is naturally hydrophobic. The depression of talc is very important and challenging in sulfide ore flotation. This research introduced aluminum ions into the process of using carboxymethyl cellulose (CMC) to depress talc. Flotation experiment results showed that aluminum ions used alone exerted a weak depression effect on talc, and that aluminum ions used in conjunction with CMC effectively depressed the flotation of talc at pH 8.5. Results of X-ray photoelectron spectroscopy and adsorption tests showed that the interaction of aluminum ions with talc changed the surface of talc, and Al(OH)3 formed on the talc surfaces, thereby promoting the adsorption of CMC onto talc and depressing the flotation of talc. On this basis, the morphology of CMC on the talc surface was observed by atomic force microscopy imaging. With the addition of aluminum ions, CMC aggregated to a greater extent, multiple layers adsorbed onto the surface of talc, and the coverage of CMC substantially increased. Based on all tests and analysis, the mechanism of the synergistic effect of CMC and aluminum ions on talc flotation was also proposed.