This equipment is a fluidized bed spinning bowl gravity concentrator. It is has been designed primarily for gold recovery from grinding circuit hydrocyclone underflows or alluvial operations. The concentrator is capable of fine and coarser feed applications. Enhanced gravity concentrators accelerate feed slurries in a rotating cone shaped bowl to take advantage of the difference in density of valuable minerals and gangue in order to perform a separation.
The material is stratified according to specific gravity and then passed over a concentrate bed fluidized from behind by pressure water. The fluidized bed is required to retain coarse particles. Free gold or gold bearing minerals are retaining in the concentrate bed in preference to light minerals. Initially the design considered non-continuous operation, but with the years the design was improved and this centrifugal concentrator can work in continuous or not. There are several types of equipments to each need. The equipment functions and rising cycle are automated with variable frequency drive device.
Generally, the higher the field or the stronger separation gravity forces between different particles of different density, the more fast and efficient is the separation. Within limits, an enhanced gravity concentrator can treat more material and recover finer particles if it is spun faster. Falcon concentrators are able of centrifugal fields of 300g. The equipment can change this value due to the unit is equipped with a variable speed motor. Concentrating surface area is the single most important determinant for enhanced gravity concentrator. Similarly to jigs or shaking tables, the larger the surface area, the higher the overall capacity since performance is a function of residence time.
The bowl has a high depth to diameter ratio when compared to other designs which means that for a given bowl diameter, Falcon has a higher unit capacity. It is not necessary to spin the concentrating surface to apply the enhanced gravity fields, it is also necessary to accelerate the slurry. If the valuable particles must travel through a thicker flowing film, they will need more time to reach the zone where they will be concentrated in the fluidized bed. The smaller the flow of fluidizing water required, the less likely this water will transport fine particles away from the retention zone. If fluidization water is injected low in the rotor before the feed material is accelerated or stratified, it is actually counterproductive to recovery because additional water is a barrier to gold particles travelling to the concentration zone and may actually wash fine gold particles out of the bowl. The holes through which the fluidization water is injected in the Falcon concentrator are perpendicular to the axis of rotation. This consideration significantly reduces the tendency for holes plugged with solids from the slurry being processed. The retention zone is deep enough to allow the fluidization water holes to be larger and more widely spaced.
Cut away schematic of a Falcon Centrifugal Concentrator Fluidization Water Injection
- Importance of Continuous Falcon Concentrator
- Operation Mechanism of the Falcon Concentrator
- How to Study the Performance of the Falcon Concentrator