The anionic flotation of fluorite from barite using gelatinized starch as the depressant

摘要

As an important non-metallic mineral widely used in industry, fluorite is normally associate with barite in nature. Anionic flotation is the most efficient method to separate fluorite from barite in mineral processing while the critical point of successful separation lies on the depressant. A cheap and eco-friendly depressant, corn starch, has been gelatinized and introduced in this study. Microflotation experiments showed that the fluorite and barite presented non-selectivity in flotation with the addition of anionic collector, sodium oleate (NaOl). By use of the gelatinized starch (GS), barite was selective depressed, leading to the high separation efficiency. The phenomenon was confirmed by the flotation of artificial mixed minerals. Zeta potential measurements demonstrated that NaOl can be adsorbed on the fluorite surface while it cannot interact with the barite in the presence of GS. X-ray photoelectron spectroscopy (XPS) indicated that the adsorption of GS on the fluorite surface mainly through physical bonding while the stronger hydrogen bonding may determine the interaction between GS and barite surface.