The “mineral dressing” industry (concentration of valuable mineral from its inevitable mixing with unwanted solids) is the classic example of the use of a very wide range of separation, filter and screen systems, centrifuges and hydrocyclones, and sedimentation tanks of all types. The filtration and separation system plays an important role in process operations for the treatment of metallic and non-metallic minerals, and often also in their extraction, where much of the recovery and processing takes place in suspension in the water.