A Flotation Cell is the individual mechanical unit that constitutes the basic building block of a flotation circuit, providing the environment — agitation, aeration, and froth formation — necessary for the selective separation of hydrophobic mineral particles from hydrophilic gangue in a slurry. Mining operations processing sulfide gold concentrates, copper ores, nickel ores, and other base metal ores rely on banks of flotation cells connected in series and parallel to achieve the desired mineral recovery and concentrate grade. In the broader context of bauxite, gold, iron ore, and diamond mining, flotation cells are most prominently used in gold ore processing plants and increasingly in iron ore reverse flotation circuits.
Modern flotation cells come in several design configurations. Mechanical flotation cells use a rotating impeller-stator assembly to simultaneously agitate the slurry, draw in and disperse air, and maintain solids in suspension. These cells range in volume from a few liters in laboratory settings to 600 cubic meters or more in large-scale industrial installations from manufacturers such as Outotec (now Metso Outotec), Eriez, FLSmidth (Dorr-Oliver and WEMCO designs), and Metso. Column flotation cells, which are tall cylindrical vessels without mechanical agitation, use counter-current flow of rising air bubbles and descending slurry to achieve high-selectivity separation, particularly in cleaning stages where high concentrate grade is more important than high mass recovery.
The performance of a flotation cell is characterized by its recovery efficiency, air dispersion characteristics (bubble size distribution, gas holdup, and superficial air velocity), residence time, and froth stability. Cell hydrodynamics — particularly the uniformity of mixing, bubble-particle collision frequency, and froth transport velocity — are critical to achieving optimal metallurgical performance. Recent advances in flotation cell technology include the development of pneumatic flotation cells for coarse particle flotation, and the application of real-time sensors for froth vision analysis using machine learning to optimize froth depth and air addition in real time.