The use of dextrin in purification by flotation of molybdenite concentrates

The process of flotation is commonly used for the recovery of molybdenite from mine tailings, but it produces low-content concentrates, thereby resulting in a product with low economic value. The low economic value is due to the presence of talc, which is a naturally hydrophobic mineral that is also floated with the molybdenite during the flotation process. Separability studies were conducted in a Partridge–Smith cell using dextrin as a molybdenite depressant in solution at different concentrations and pH values to produce a technical-grade concentrate (i.e., 90% MoS2). These basic studies were accompanied by measurements of the zeta potential and contact angle, which was determined by the capillary rise method. The results of these floatability studies were used in bench tests of flotation, which were performed in a Denver D-12 cell. A molybdenite concentrate of 93.4% MoS2 was obtained when dextrin was used at a concentration of 100 g/t.