This unit is ideal for batch tests on moderate quantities of ore to determine the application of the sink-float process in large scale operations. Operation of the unit is simple and consists of filling the system with plus 3 specific gravity medium and circulating it through the pump. The ore sample is fed to the upper basket and the lightweight gangue (float) overflows and is retained in the lower basket. The heavy mineral fraction (sink) collects in the upper basket. The flow of the media is upward through the upper funnel and overflowed to the lower funnel and back to the pump. The upward current is low enough to counterbalance the tendency for the media to settle. The funnels are fitted with removable baskets. The amount of media removed is negligible. Therefore, the specific gravity remains constant for long periods. The unit is furnished complete with pump, piping, screen baskets, funnels, steel stand, and motor.