Patent ID: 8360246

Claim:
A froth flotation method for extracting a valuable substance from a slurry (S) comprising a mixture of solid phase, liquid phase and the valuable substance, the method including the steps of delivering gas into the slurry (S) in a flotation vessel ( 1 ) to infuse gas bubbles into the slurry; dispersing the gas bubbles into the slurry said gas bubbles capturing said valuable substance from the slurry and forming a froth phase (F) above the slurry phase said froth phase to be removed from the vessel by overflow over an overflow lip ( 2 ) into a froth launder ( 3 ), and dispersing wash water (W) into the froth phase (F) to wash out undesirable hydrophilic fine particles entrained from the slurry phase to the froth phase, characterized by the steps of arranging an upwardly open circular trough ( 4 ) having a range of distribution outlets ( 5 ) on the outer periphery of the trough horizontally above the froth phase (F) so that the trough is coaxial with the flotation vessel ( 1 ), and said circular trough is rotated around its center axis, arranging a stationary water pipe ( 6 ) above the trough ( 4 ), feeding fresh water (W) via the water pipe ( 6 ) into the trough ( 4 ) while the trough is rotating, and distributing the wash water by gravity and centrifugal force from the trough ( 4 ) via the distribution outlets ( 5 ) into the froth phase (F).