Bateman has developed the APIC Jig, which is an underbed air-pulsed gravity separator that separates particles of different specific gravity in a homogeneous bed of solid material. The technology itself was developed by the Fives-Lille Group of France, and the life-cycle of this product has been extended in southern Africa. Originally, the unit was developed for coal washing operation, and the good results have indicated that it is possible to use this unit in the fields of mineral engineering, especially ferro-alloy and other metal recovery from slag, and the upgrading of both metallic and non-metallic orebodies. Some tests haven done on gold ores.
The mechanism of the jig involves the underbed air pulsation of water in the unit which submits an homogeneous bed of particles on a screen deck to vertical fluid pulses of extension and compression phases. This produces a densimetric stratification of the particles with the denser, heavy particles sink and settling, and the lighter or less dense particles float and rise to the top of the material bed. The discharge is controlled by a float that is continually positions at the desired density interface within the bed and its design is chosen to suit the particular feed size distribution and the proportion of sinks.
The pulse characteristics are designed to maximize the separation of products in the jig and electronic control provides a precise and consistent operation, regardless of feed variation. The pulse timings within each of the jigs compartments are automatically adjusted for bed level variations. Inlet air pressure is automatically regulated to provide the correct pulse strength for the application, whilst the exhaust air pressure is regulated to control the suction stroke and the settling behavior of the particles.