Concentration process based on the ability of denser particles to float to the surface and lighter particles to sink to the bottom of a medium when the specific gravity of the medium is between those of the denser and lighter particles.. The medium may be a dense liquid, a solution, or a finely ground material in suspension in water (heavy media). The process may static. It takes place in a drum or a tank. It may be dynamic. It is then effected in a cyclone. The lighter product is sometimes referred to as float, the heavier as sink. This is a gravity separation process.