Flotation is a method for the separation of mixtures. Flotation is a separation technique used widely in the minerals industry, for paper deinking and water treatment amongst others. The technique relies apon differences in the surface properties of different particles to separate then. The particles that are to be floated are rendered hydrophobic by the addition of the appropriate chemicals. Air is then bubbled through the mixture and the desired particles become attached to the air and move to the surface where they accumulate as a froth and are collected.