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Amgueddfa Cymru
Black and white photograph showing the "chance" flotation process at a coal cleaning plant.
This photograph shows the lower end of the cone which contains the sand and water mixture upon which the clean coal floats. Here the heavy refuse - shale - which has fallen through the sand-water mixture, is discharhed on to a vibrating screen, by means of which it is separated from the water and sand which have been discharged with it.
