Abstract: Coarse particles of up to 3 mm are floated in a cylindrical froth flotation cell in which the agitation impeller has a cover preventing fluid from being drawn in above. Air is supplied from a ring around the periphery of the cell and situated above the cover. Baffles project radially inwardly up to a short distance from the top. Froth is allowed to overflow around the periphery of the cell. The opposed inlet and outlet are disposed respectively below the level and at the level of the impeller. The arrangement is such that the liquid below the layer of froth is substantially quiescent.