Flotation separation of scheelite from gypsum using Pb-BHA complex collector

Due to the presence of tungsten ore in association with gypsum and the necessity to extract tungsten from gypsum slag, research into the flotation separation of scheelite from gypsum has become imperative. In this paper, flotation experiments and mechanism studies of Pb- benzohydroxamic acid (Pb-BHA complex) collectors on the separation of scheelite from gypsum were carried out. Flotation experiments revealed that the Pb-BHA complex collector demonstrated superior selectivity over dodecyl amine (DDA) and sodium dodecyl sulfonate (SDS), with an efficacy improvement in alkaline conditions. The selective separation of scheelite from gypsum was achieved by Pb-BHA collectors. Zeta potential, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses indicated chemisorption of Pb-BHA collectors on the surfaces of scheelite and gypsum, with notably higher adsorption levels observed on scheelite compared to gypsum. The quantum chemical computational results indicated that the Pb-BHA complex collector interacted with the O atoms of anion groups on the scheelite and gypsum surfaces through the Pb sites, and the adsorption on the scheelite surface was stronger than on the gypsum surface. The novel collector, Pb-BHA complex, exhibited enhanced flotation selectivity compared to traditional collectors, introducing a new approach for the separation of scheelite from gypsum.