Abstract: The invention relates to the concentration and benefication of particulate matter by froth flotation and in particular to improvements in hydraulic-pneumatic flotation apparatus which contributes to efficiency of operation. Such apparatus employs a constriction plate which separates vertically arranged flotation and aerating compartments. A discharge duct may be used to extend through the aerating compartment and to open through the constriction plate centrally thereof. Orifices in both the constriction plate and the discharge duct are in communication with the aerating compartment to provide a uniform dispersion of air bubbles in the flotation compartment. To prevent build-up of non-float fraction on the constriction plate, the latter may be dish-shaped toward the discharge opening. In an alternative embodiment, the discharge duct is omitted and the constriction plate is conically shaped with the apex uppermost.

Abstract: A vibrator device, especially for connecting to a screen element for agitating the screen element, and including rotary shafts with off-center weights so oriented relatively that the agitation of the screen takes the form of vibratory movement thereof in one direction with a stronger impulse being imparted to the screen in one direction than in the other.