Froth Flotation Cells
Froth flotation is a highly versatile method for physically separating particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in a mineral/water slurry.
The particles with attached air bubbles are then carried to the surface and removed, while the particles that remain completely wetted stay in the liquid phase.
Froth Flotation Cells are effective for the beneficiating of fine coal <0.5mm.
Fine coal can be separated from shale and other waste by using a process including froth flotation cells.
The coal is made water repellent by the addition of a reagent such as oil, so that when a suspension of coal is agitated with air it sticks to the air bubbles and floats to the surface, collecting as froth.
Shale and other waste are not wetted by the reagent due to the different nature of their surface and hence do not stick to the bubbles and remain in the suspension to be drawn off the froth flotation cells at a controlled rate, the froth is removed from the upper cell weir by the assistance of rotary paddles.