Wet centrifugal classification of calcite fines — effect of feed size

The wet classification of various fine calcite materials (<8, <12 and <45 μm) by a diskstack nozzle centrifuge is presented and the results are discussed with respect to feed size. It has been found that the influences of disk-geometry, G-force and feed rate on the classification performance are not related to feed size. However, the selection of a split suitable for an efficient separation depends on the particle size distribution of the feed material. Feed size has an impact on the residence time of particle separation. The results showed that an optimum efficiency can be achieved when a calcite material with a particle size below 12 μm is treated. An excessive amount of fine or coarse calcite particles in the feed affects the efficiency of the classification in the centrifuge. It is also indicated that an effective classification of calcite fines requires a moderate G-force and high flow rates through a disk section bound by stud spacers in the centrifuge.