Modelling of binary mixture comminution.

Abstract

This paper treats on grindability differences of mineral mixtures to achieve a preliminary selective particle size contrast by comminution in order to improve further sorting operation. Quartz and calcite had been chosen as example of binary system. The theoretical basis for this work was inspired by the optimization study carried out by Ray and Szekely (1973), through an algebraic model based on evolution of log-normal distribution of particle size during comminution. On the other hand, the present work has described grindability differences through the classical Rosin-Rammler size distribution. The study of the evaluation of binary mixture differences was realized by sieving analyses and the estimation of Rosin-Rammler sharpness and median diameter. An objective function was conceived stressing the relationship between the expended energy in the grinding process and the optimum residence time. It is possible to use the results as a background for grinding optimization system, since that the penalty function inside objective function can be adequately calibrated as far as technical and economic impacts on further sorting separations are concerned.