Influence of sodium silicate on the selective dispersion and flotation separation of ilmenite against fine titanaugite in hydrophobic systems

Fine titanaugite readily adhered onto ilmenite surfaces in hydrophobic systems, resulting in a minor difference in floatability. This study utilized sodium silicate (WG) to address these issues. Flotation experiments showed that the serious non-selective hydrophobic aggregation of particles resulted in a low sorting index of a 44.81% TiO2 grade and a 16.02% TiO2 recovery when using conventional dispersants in flotation separation of actual ore. However, after utilizing WG, the index of flotation concentrate raised to a 46.50% TiO2 grade and a 19.84% TiO2 recovery. Turbidity analysis proved that WG had the strongest destructive impact on the non-selective hydrophobic aggregation between fine titanaugite and ilmenite particles compared to other dispersants. FTIR and XPS analyses verified that WG was inclined to adsorb onto titanaugite surfaces than ilmenite surfaces via physical adsorption. Zeta analysis proved that the selective adsorption of WG prevented the collector adsorption on titanaugite surfaces, while it had little effect on ilmenite surfaces. After adding WG, these changes in reagent adsorptions caused the increase of floatability difference of ilmenite and titanaugite and weakened the heterogeneous hydrophobic aggregation between particles by diminishing hydrophobic attraction. Taken together, WG has superior selective dispersion and inhibition in ilmenite flotation.