GRINDING CIRCUIT FOR FINE PARTICLES IN LIQUID SUSPENSIONS WITH A NEW COUNTER-FLOW CENTRIFUGAL CLASSIFIER

This paper presents a centrifugal classifier operating on the principl e of counter-flow which achieves a high sharpness of cut even in conce ntrated suspensions in the superfine range. By means of this pilot pla nt, investigations into the influence of the respective operating para meters (centrifugal acceleration, flow velocity in the classification zone) were carried out. As a consequence, the cut size can be adjusted within a wide range and calculated theoretically on the basis of Stok es settling rate in the centrifugal field. It follows that this centri fugal counter-flow classifier makes it possible to establish a grindin g circuit for fine particles. Thus, the fine particles, the end produc t of the classifying procedure, are obtained in the desired degree of fineness. In addition to that, test results obtained from a grinding c ircuit by means of a stirred ball mill will be presented. The grinding circuit product has a steeper and finer particle size distribution th an all products of multiple grinding tests. Also the energy consumptio n of the circuit is much lower.