Behaviour of rocks in crushing

Differences in the behaviour of rocks in crushing may be noticed in the size distribution, in the shape of the particles produced and in the energy consumed during size reduction. Much work has been done to arrive at a relation between the energy consumption and the size reduction. Little or no work has been done to study the differences in the size distribution of the crushed products and the probable reasons for the same. In the present study an attempt has been made to study the factors influencing the size distribution and the shape of the particles produced during crushing. The study indicated that the size distribution in crushing is mostly dependent on the properties of the rock, such as the grain size, macro-and micro-binding and weathering. The percent of fines (-200 mesh) produced is found to depend on the hardness of the constituent minerals of the rock. The factors responsible for producing differently shaped particles are discussed. (V. Malleswara Rao, Department of Mining, Osmania University, Hyderabad)