In this study, a computer simulation of a suitable matrix notation of the Broadbent and Callcott grinding model was written. First, a chromite sample was ground in the laboratory type batch ball mill at different grinding times, with different particle size distributions and different capacities. Second, elements of the matrix for computer simulation were found and a "milling matrix" was formed. Third, particle size distributions were predicted by computer simulation for the whole test. Finally, a relationship between the computer simulation predicted by dates and experimental results was established, with a good correlation within the limits of mean error values.