Insight into the physical assembly of alkanes with Z-200 molecules on surface hydrophobicity of chalcopyrite (CuFeS2)

Abstract

Copper flotation usually utilizes the synergistic effect between different collectors to improve the recovery. Currently, there are few studies on the assembly of nonpolar alkanes with collectors for flotation practice, not to mention the lack of micro-mechanism studies. In this study, the effect of the physical assembly of alkanes with Z-200 on the surface hydrophobicity of chalcopyrite was systematically investigated by flotation, contact angle and microcalorimetric tests, density functional theory and molecular dynamics calculations. It was found that the assembled reagents exhibited better collection ability towards chalcopyrite than Z-200, required lower dosages and exhibited higher recoveries. The assembled reagents made chalcopyrite surface more hydrophobic. The adsorption of assembled reagents on chalcopyrite surface was much more intense than that of the single reagent. Alkanes could not spontaneously adsorb on chalcopyrite surface, and after assembly, alkanes were assembled with chemisorbed Z-200 by van der Waals forces and co-adsorbed on the mineral surface. The assembled reagents were tightly arranged and more hydrophobic than the hydrophobic layer with only Z-200 adsorbed. The study revealed the assembly mechanism between Z-200 and alkanes at the solid-liquid interface of flotation, which provided a theoretical basis for the development and design of novel collectors for mixed sulfide ores.