Influence of particle shape on dynamic DMS processes.

A new methodology has been developed for determining the partition curves in dense medium separation using tracer particles of fixed density but of different shape and size - including cubes, elongated and flat particles - and modifying the density of the medium. From the partition curves, values could be determined for the sharpness of separation Ep, the cut density, and the difference (or offset) between cut density and medium density - which is an important parameter in processing. It was found that single particle sizes and shapes are separated with high sharpness in both conical and cylindrical (Tri-Flo) cyclones; in contrast the offset value is dependent on particle size and shape, with large variations: conical cyclones have high positive offset values and the cylindrical have lower values from positive to negative. The applications of the results for processing materials which have different shapes, such as wastes and secondary materials, are discussed.
A new methodology has been developed for determining the partition curves in dense medium separation using tracer particles of fixed density but of different shape and size - including cubes, elongated and flat particles - and modifying the density of the medium. From the partition curves, values could be determined for the sharpness of separation Ep, the cut density, and the difference (or offset) between cut density and medium density - which is an important parameter in processing. It was found that single particle sizes and shapes are separated with high sharpness in both conical and cylindrical (Tri-Flo) cyclones; in contrast the offset value is dependent on particle size and shape, with large variations: conical cyclones have high positive offset values and the cylindrical have lower values from positive to negative. The applications of the results for processing materials which have different shapes, such as wastes and secondary materials, are discussed.