Effects of barite size on the fluorite flotation using the reagent scheme of GS/NaOl

Abstract Barite is easily ground to slime fraction, which may affect the fluorite flotation. The role of barite particle size in the fluorite flotation was studied in this work. Single mineral flotation showed that gelatinized starch (GS) selectively depressed the barite flotation with different size fractions while it had little effect on fluorite flotation using sodium oleate (NaOl) as the collector, suggesting the sufficient separation of fluorite from barite using the reagent scheme of GS/NaOl. However, the flotation of mixed minerals presented that the existing of fine barite particle significantly interfere with the fluorite flotation. Zeta potential measurements, turbidity tests, and light microscope observations revealed that the hetero-coagulation occurred between fluorite and barite slimes, causing the slime coating of barite onto the fluorite surface. GS not only acted as the depressant but also act as the flocculant to improve the apparent size of barite, while it still could not completely eliminate the detrimental effects of slime coating due to the entrainment of fluorite-barite aggregates. The additional methods to obtain the effective flotation separation of fluorite from barite slime were tested and discussed.