Effects of oxidation roasting on surface characteristics and flotation behavior of bastnaesite

• • Oxidation roasting at elevated temperatures, extended time, and higher O2 concentration increased Ce oxidation degree and REO grade beyond 85.00%, directly enhancing rare earth enrichment but requiring higher collector dosage for >85.00% flotation recovery. • • Thermal decomposition produced Ce7O12 and REF3 phases, creating a complex crystal structure and long, nearly parallel cracks that penetrated particles, increasing porosity and causing fragmentation—this improves wettability but complicates flotation selectivity. • • Dissolved rare earth ion concentration rose significantly during flotation, with surface hydrolysis forming rare earth hydroxyl compounds, which altered the chemical adsorption of SHA and necessitated higher reagent addition. • • SHA adsorption occurred both internally and externally due to surface cracking, increasing collector consumption; this implies that flotation optimization must account for porous particle architecture to avoid excessive reagent costs.