Abstract: In a flotation machine rotor, a body portion defines an interior area that is adapted to communicate with a gas source. At least one rotor blade projects radially outwardly from the body portion with at least one aperture being defined thereby and in gaseous communication with the interior area. The aperture is positioned adjacent the rotor blade and is defined in part by a lower peripheral edge. At least one lip projects radially outwardly from the lower peripheral edge so that during operation of the rotor, solids traveling along the body portion are projected radially away from the rotor by the lip and become approximately aligned with the aperture so that gas flowing from the aperture creates bubbles in the slurry that entrain at least a portion of the solid particles. The bubbles and solid particles form a froth on the surface of the slurry which can then be removed from the flotation machine.