Abstract: A continuous concentrator for high volume specific gravity separation of materials, particularly constituent materials of indigenous ores, in a counter-current process, the concentrator includes a continuous loop conveyor constructed with a conveyor bed on which are mounted periodic transverse riffles, and raised sidewalls for containing ore materials deposited on the bed from an ore feed; and, a bar sweeper constructed with a pair of continuous loop, link drives interconnected by transverse sweeper bars adjustably positioned over the conveyor bed, the bar sweeper being operated with the sweeper bars moving proximate the top of the conveyor riffles in an opposite direction from the movement of the conveyor, the rate of movement of the bar sweeper and conveyor being independently controlled for processing ores of different composition or consistency, wherein heavier metals and minerals are conveyed in one direction on the conveyor bed to one end of the conveyor for discharge and collection, and the lighter met