Comminution environment-defined collector adsorption behaviour of copper sulphide ore

• Grinding condition alters CuFeS 2 surface reactivity, impacting collector adsorption. • Xanthate adsorption occurs on both dry and wet-ground chalcopyrite at all pH levels. • Dry-ground surfaces exhibit greater collector adsorption than wet-ground surfaces. • Adsorption trends align with surface characterization and residual solution result. • Dry grinding resulted in higher copper recovery and grade compared with wet grinding. The grinding environment—whether wet or dry—significantly impacts the surface and pulp chemistry of copper sulphide minerals, which in turn affects collector adsorption. However, the relationship between mineral surface alterations from different grinding conditions and collector adsorption is not fully understood. This study investigates the collector adsorption behaviour of model chalcopyrite mineral and chalcopyrite-containing ore subjected to both dry and wet grinding. The collector adsorption behaviour was analysed using froth flotation tests, and advanced characterization methods such as ultraviolet-visible spectroscopy, zeta potential, X-ray photoelectron spectroscopy, Fourier Transform Infrared Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The results, in the absence of collector (potassium amyl xanthate), showed isoelectric points of approximately pH 2.1 for dry-ground chalcopyrite and pH 2.7 for wet-ground chalcopyrite. In the presence of collector, significant adsorption was observed on both dry and wet ground chalcopyrite surfaces across all pH levels, with more pronounced adsorption on the dry-ground sample. The observed higher collector adsorption on dry-ground particles is consistent with results from particle surface characterisation and residual solution collector concentrations. Flotation studies showed that dry grinding resulted in higher copper recovery (82 wt.%) and grade (8.5 wt.%) compared with wet grinding where 78 wt.% copper recovery and 8.1 wt.% Cu grade was observed. This demonstrates the significant influence of grinding environment on collector adsorption and flotation performance.