METHOD FOR INCORPORATION OF SHAPE CHARACTERIZATION INTO CONE CRUSHER MODEL

Roadstone production requires the generation of a non-flaky material, as outlined in British Standard 812 (section 105.1), if an unsalable p roduct is to be avoided. With respect to this criterion a mathematical model of a cone crusher that is specific to the requirements of the a ggregates industry must, in addition to predicting the size distributi on of a product, be able to predict the flakiness index of a particula r size range. The flakiness index avoids the problem of a rigorous def inition of particle shape by assigning particles into only two categor ies, flaky and non-flaky, as determined by the relationship between th eir smallest dimension (thickness) and nominal size. The Whiten cone c rusher model utilizes breakage and classification functions to predict a product particle-size distribution only. A shape function has been incorporated to enable the model to predict a product-shape distributi on. The proposed method adopts a phenomenological approach by taking i nto account the transfer between flaky and non-flaky material at each stage of breakage. The results of laboratory tests to determine materi al breakage characteristics and of an examination of the products obta ined in tests with a pilot-scale machine are presented to illustrate t he potential of the method.