Flotation method for coal having poor floatation

摘要

A flotation method for a coal having poor floatation comprises the following steps: supplying, by means of a pump (E), a solution containing nanobubbles (5) to a mineral slurry mixing tank (F), and simultaneously supplying an appropriate amount of coal (7) and a flotation reagent (8) to the mineral slurry mixing tank (F); and supplying, by means of a material feeding pump (G), a mineral slurry mixture (9) to a countercurrent static micro-bubble flotation column (H) to undergo floatation, thereby obtaining two resulting products, a fine coal (10) and a tailing (11). The flotation reagent consists of the following components: a kerosene, isopropyl ethylthionocarbamate, Tween 40, sodium alcohol ether sulphate, p-Toluenesulfonic acid, Span 60, phthalic anhydride, sodium dodecyl benzene sulfonate, and benzenedicarboxylic anhydride. The method utilizes a property of nanobubbles that the same preferentially gather at a hydrophobic surface, increasing the difference in hydrophobicity between the fine coal and coal gangue. The gathering of the nanobubbles also significantly reduces a fine mud covering a coal particle surface, thereby greatly reducing contamination caused by the fine mud, and increasing a recycling rate of the fine coal.