USE OF CONTINUOUS-FLOW CENTRIFUGATION TECHNIQUES FOR COAL MACERAL SEPARATION .2. MULTIPLE DENSITY FRACTIONATIONS OF COALS

Continuous flow centrifugation (CFC) methods were used to density fractionate macerals from three different finely ground coals. Moderate to excellent enrichments were produced. However, the purities of the separated fractions were not straightforward to predict; they were controlled in a complicated manner by the dynamics of the centrifuge, the density chosen for each fractionation, and the density distribution of the coal. In addition, the role that the size of the density interval of fractionation has on the purity of separation is discussed.