Method and apparatus for flotation separation

A method of separating a selected constituent from an effluent of an industrial process comprising the steps of:

• mixing the effluent with a flotation reagent;
• dissolving gas into the effluent;
• introducing a resulting effluent, flotation reagent and dissolved gas mixture into a third chamber of a flotation cell acting as a rougher separator in fluid communication with a first chamber of the flotation cell under conditions promoting a release of dissolved gas as microbubbles in the mixture, said third chamber having a longitudinal axis extending at an angle substantially perpendicular to a longitudinal axis of said first chamber;
• recovering floated selected constituent from the first chamber and delivering non-floated tailings from the first chamber to a second chamber of the flotation cell;
• sparging gas into the non-floated tailings delivered to the second chamber;
• and
• recovering the selected constituent from the non-floated tailings being processed in the second chamber.