Theory and application of column flotation

The flotation mechanisms of various flotation machines are reviewed briefly. The inherently superior flotation mechanism of a countercurrent flotation column is described in more detail and is compared with that of conventional, mechanical flotation machines. The merits of countercurrent column flotation include: improved metallurgical performance in terms of grade and recovery; effective cleaning action in the long cleaning zone with a blanket of fresh water; smaller floor space required because of its vertical configuration; low capital, operational, and maintenance costs because of the absence of moving parts; and finally, easier flotation control as a result of the simplified circuit. Flotation studies on various minerals and coal at CANMET indicate that the Canadian countercurrent flotation column performs better than conventional, mechanical flotation cells in terms of concentrate grade and recovery. Some industrial experiences with the Canadian flotation column on various sulphides, oxides, and coal are also presented.