The article provides findings of analytical research into the process of milling friable matter in a ball mill. We have received an expression to determine energy cost of milling with the account of the method of milling and the characteristics of the material to be ground. In the paper, the analytical results of bulk materials grinding process in a ball mill are presented. The differential equation is obtained whose solution determines the value of the grinding mode coefficient, corresponding to the maximum value of grinding process efficiency. The use of the introduced ball mill modes allows reducing the time spent on grinding by 28.9 % for cement clinker, 18.4 % for black coal, 28.9 % for marble and 19.6 % for rock salt compared to the traditionally recommended ones