Effect of sodium carboxymethyl cellulose on the interaction between hematite particles and bubbles

Sodium carboxymethyl cellulose (CMC) is a potential depressant which is an indispensable reagent for the treatment of complex refractory iron ores during reverse flotation. In this study, the interaction force between hematite particles adsorbed with CMC and bubbles was calculated, thereby revealing the inhibitory mechanism of CMC on hematite particles. When dodecylamine (DDA) was 15mg/L and CMC was 3mg/L, pH=10, the content and recovery rate of hematite reached 83.25% and 87.41%, respectively. Zeta potential tests showed that adsorption of CMC hindered the adsorption of DDA on hematite. AFM images visualized the adsorption status and adsorption layer thickness of CMC on the surfaces of hematite and quartz. FTIR results indicated that the adsorption of CMC on the surface of hematite was strong chemical adsorption, but the adsorption on quartz was physical adsorption. Based on the extended DLVO theory, the total potential of interaction between hematite particles adsorbed with CMC and bubbles was measured. The calculation results demonstrated that the hydration repulsion interaction potential owing to the adsorption of CMC dominated the total potential energy, preventing the adhesion of hematite and bubbles.