Surface Analysis of Complex Ore to Compare Collector Adsorption from Alternative Dosing Methods

Aerosol phase introduction of xanthate collectors has recently been shown to enhance coarse particle flotation performance; however, the mechanistic origins of this improvement remain poorly understood. This study provides the first direct, statistically supported assessment of collector adsorption onto complex, heterogeneous ore particles when reagents are delivered via the gas–solid interface in comparison to conventional aqueous pre-conditioning. Using fluidized bed flotation of a chalcopyrite bearing copper ore, combined with molecular scale surface analysis via Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), we compare mineral surface exposure and collector adsorption between the two dosing methods for the +300–425 µm size fraction of the flotation concentrates. Flotation testing showed a substantial increase in copper recovery (66% to 86%) when the collector was added as an aerosol, accompanied by a moderate rise in gangue recovery, indicative of reduced liberation requirements for successful flotation. ToF-SIMS elemental mapping confirmed that aerosol recovered particles exhibit significantly lower surface exposure of sulfide minerals and greater siliceous surface expression, demonstrating recovery of less-liberated particles than pre-conditioning. Quantification of SIBX-derived fragments revealed a ~69% increase in CS2 attaching moiety signal intensity under aerosol dosing, providing direct evidence of enhanced collector adsorption. These results establish that aerosol phase delivery simultaneously increases adsorption density and enables flotation of particles with smaller chalcopyrite surface exposure, offering new pathways for optimizing reagent delivery and future modeling of flotation chemistry.