Mitigation strategies of salicylhydroxamic acid collector with oxalic acid in goethite flotation

Abstract

Flotation of goethite, a representative mineral of laterite ore, which is essential source of nickel used in secondary batteries, was conducted using salicylhydroxamic acid as the collector. The presence of ferric ions derived from goethite in the pulp resulted in an increased consumption of the collector during flotation. Following three washing stages, the maximum recovery of 98.5 wt% was achieved with a collector dosage of only 60 % in the absence of a washing stage. The oxalic acid is employed to eliminate ferric ions via precipitation without the requirement for supplementary water, energy, and time-consuming washing stages. The utilization of 40 g⋅t⁻¹ of oxalic acid yielded comparable recovery outcomes to those observed in the three washing stages. Furthermore, theoretical investigations were conducted to determine the collector species influencing goethite flotation with density functional theory. It was observed that compared with that of goethite with non-ionized salicylhydroxamic acid complex, the complexation energy for goethite with ionized salicylhydroxamic acid was lower by 113.9 kJ⋅mol⁻¹, indicating that the optimum adsorption onto the mineral surface strongly depends on ionized salicylhydroxamic acid species. This study presents a potential method for reduction of reagent consumption in the flotation of future complex laterite ore, an acidic soil in which metal ions might be present. Additionally, the theoretical framework elucidates the complexation of collectors to minerals that are challenging to quantify experimentally.