Selective adsorption of a novel X-shaped surfactant dioctyl di-hydroxamic acid on fluorite surface leading the effective flotation separation of fluorite from calcite and barite

• Novel collector (DODHA) was used in fluorite/calcite/barite flotation separation. • Effective enrichment of fluorite in the absence of depressant can be achieved. • DODHA is lattice matched with fluorite surface favors the adsorption of DODHA. • Steric hindrance also plays a key part in determining the selectivity of DODHA. During fluorite flotation, the separation efficiency of fluorite from barite and calcite was low owing to their similar surface properties, therefore, developing highly selective flotation collector for fluorite is urgently needed. In this study, a novel surfactant, dioctyl di-hydroxamic acid (DODHA), was found as an effective collector for flotation separation of fluorite, calcite, and barite. Results from flotation tests suggested that the effective enrichment of fluorite from calcite and barite could be realized without the addition of depressants. FTIR, ζ potential, and XPS results indicated that the interaction between DODHA and fluorite was strong, whereas the adsorption of DODHA on calcite and barite was negligible. The DFT calculation, surface property, and molecular structure analysis results indicated that the steric hindrance and lattice matching between DODHA and mineral surface determined the superior selectivity of DODHA.