A comparison of particle bed breakage and rod mill grinding with regard to mineral liberation and particle shape effects

Samples of a chromite ore were ground by conventional rod mill and by piston-die press. Five size fractions of products from the two comminution devices having different modes of breakage were analyzed for the percent degree of chromite liberation and particle shape by an image analysis software. Results confirmed enhanced liberation in particle bed breakage achieved in the piston-die press. Particles ground in the rod mill had no shape differences as a function of particle size. Particle bed breakage generated particle profiles with less circularity at the finer end of the investigated size spectrum.