The Knelson Concentrator relies on an enhanced gravitational force together with fluidization process to recover even very micron sized particles. First water is injected into the rotating concentrating cone through series of fluidization holes. Then feed slurry is introduced through a stationary feed tube. Once the slurry is filled in each cone, create a concentrating bed and high specific gravity particles are retained in the cone and then flushed into the concentrate launders. This procedure can be completed in less than one minute.

The Knelson concentrator (KC) is a vertical axis bowl-type centrifugal concentrator that uses a fluidized bed to perform its concentrating duty. It was first introduced as a semi-batch unit and has gone through several iterations of design leading to the development of a continuous discharge machine. It has now become almost an essential unit operation in any gold processing plant to assess the gravity recoverable gold content in the ore as well as to recover fine free gold from the grinding circuit.