Effects of Seawater and Collector Magnetization on Chalcopyrite Flotation

Seawater flotation is increasingly adopted to reduce freshwater demand; however, its complex ionic environment often deteriorates sulfide mineral floatability and necessitates effective regulation strategies. In this work, seawater magnetization and collector magnetization were evaluated as two independent treatment routes affecting chalcopyrite flotation, and their impacts on flotation performance and interfacial properties were quantified. Pure-mineral flotation tests were conducted at pH 8 using butyl xanthate as the collector and pine oil as the frother, with magnetic field strength and magnetization duration varied in a controlled manner. Both flotation recovery and interfacial responses exhibited a distinct parameter-window behavior, rather than a monotonic enhancement. Under magnetized seawater conditions, chalcopyrite recovery increased from 80.45% to 92.7% at 200 mT and 8 min, while magnetized collector treatment under identical conditions produced a stronger enhancement, yielding a maximum recovery of 96.5%. Contact-angle measurements demonstrated an increase in chalcopyrite surface hydrophobicity within the effective magnetization range, whereas zeta-potential measurements revealed a positive shift toward less negative values, indicating weakened electrostatic repulsion in the seawater system. The consistent trends among flotation recovery, surface wettability, and surface electrical properties suggest that magnetization influences chalcopyrite floatability by modifying the balance between hydrophobic surface stabilization and electrostatic interactions, thereby highlighting an effective operating window for seawater flotation systems.