Study on Flotation Behavior of Fine Flake Graphite Enhanced by Nanobubbles

It is difficult to collect fine graphite particles because of the large size and small specific area of traditional flotation bubbles. The contrast experiment between nanobubble flotation and traditional flotation of micro-fine flake graphite in the Hegang area of Heilongjiang Province was carried out in this paper. Under the conditions of feed fineness 78% (-74 μm), pH 10.5, sodium hexametaphosphate 800 g/t, No. 2 oil 350 g/t, pulp concentration 10%, diesel 400 g/t, and pulp cycle time 3 min, the enhanced behavior of nanobubbles on micro-flake graphite flotation was discussed by studying the differences in the flotation rate, selectivity, pulp size, and concentrate size between traditional flotation and nanobubble flotation. The results showed that the nanobubble flotation completed the flotation 20 s earlier than the traditional flotation, and the final concentrate recovery of nanobubble flotation was 1.5 percentage points higher than the traditional flotation. In addition, the average particle size of the slurry from nanobubble flotation is 13 μm larger than that from traditional flotation. In addition, the minimum size of nanobubble flotation is only 2 μm, 11 μm smaller than the minimum size of traditional flotation. Nanobubbles effectively reduce the electrostatic repulsion between fine particles and enhance the hydrophobic attraction, making the hydrophobic aggregates of fine particle graphite more stable. At the same time, the presence of nanobubbles makes the surface hydrophobicity of graphite stronger, effectively promoting the recovery of fine particle graphite.