Flotation performance and selective adsorption mechanism of novel hydroxamic acid on the separation of fluorite from barite

Abstract

Effective flotation separation highly depends on the selective adsorption of reagents on the mineral surface. This research found that the novel hydroxamate-based collector, octylamino-bis-(propanohydroxamic) acid (OPHA), could selectively adsorb on fluorite surface thus rendering the effective flotation separation of fluorite from barite. Macroscopic measurement methods, such as ζ potential, FTIR, and XPS tests, revealed that the adsorption of OPHA on fluorite surface was stronger than that on barite surface. DFT calculation results indicated that the interaction strength between H2O, OPHA+, and OPHA2− with fluorite surface was in the order from OPHA2−, OPHA+ to H2O. In the case of barite, the adsorption of OPHA2− was still the strongest, whereas the adsorption intensity of OPHA+ on barite surface was lower than that of H2O.