Effect of dissolved gases in natural water on the flotation behavior of coal

The effect of dissolved gases in natural water on the flotation behavior of coal was investigated by a combination of flotation tests, dynamic froth stability measurements, pulp rheology measurements, settling tests and induction time measurements. Better flotation performance with a lower dynamic froth stability (DFS) value was achieved in natural water compared to degassed water. Both pulp rheology and settling results showed that the gases dissolved in natural water enhance the formation of bubble-included aggregates. In addition, dissolved gases reduce the induction time between coal particles and bubbles, resulting in the easier capture of coal particles by the bubbles. All these variables are responsible for the improved flotation performance observed in natural water.