Abstract: A flotation line for treating mineral ore particles suspended in slurry is disclosed. The flotation line includes a rougher part with at least one rougher flotation cell from which overflow is arranged to flow directly into a cleaner flotation line; and a scavenger part with at least two scavenger flotation cells from which overflow is arranged to flow back into a rougher flotation cell, or into a regrinding step and then into a cleaner flotation line. Underflow from a last scavenger flotation cell is arranged to be removed from the flotation line as tailings. At least 75% of the flotation cells include a mechanical agitator including a system for introducing flotation gas into the flotation cell. At least one of the flotation cells of the flotation line includes a mechanical agitator including a microbubble generator for introducing microbubbles into the slurry.