Abstract: A multi-constituent mixture of particles is fluidized within an elongated container with a gas permeable base. Opposing horizontal motions are induced in the upper and lower strata of the fluidized material by means of moving baffles mounted on endless chains within the confines of the container. A potential difference established between a horizontal electrode located in the upper part of the container above most of the bed surface, and the base of the bed induces electrostatic forces on the tribo-electrified particles, thereby affecting the distribution of the vertical composition of the mixture in the bed.The combination of the opposing horizontal motions and vertical segregation results in a horizontal concentration gradient. The particles thus separated are removed from the ends of the bed by, for example, flowing over weirs.

Abstract: Fluidized particulate material in an elongated fluidizing bed is separated by means of paddles, on an endless chain running around sprockets, urging at least an upper portion of the fluidized bed towards one end of the bed to enrich that end with lighter particles and the other end with heavier particles. The particles thus separated are removed from the ends of the bed by, for example, flowing over weirs. In one embodiment only the paddles passing along the underside of the chain dip into the fluidized bed while in another embodiment the whole chain and all of the paddles are immersed in the fluidized bed.