Comminution of single particles in a rigidly-mounted roll mill part 1: mill torque model and energy investment

A mathematical description of single-particle comminution in a rigidly mounted roll mill is presented. When tested against the extensive experimental data pertaining to barite, calcite, dolomite, galena, hematite, limestone and quartz particles, the model of the mill torque correlates reasonably well with the important operating parameters such as roll speed, roll gap, particle size and feed rate. The energy investment for comminuting single particles in the roll mill varies with particle size in the manner of a power function law, whose exponents are in reasonable agreement with published data for fracture of particles in uniaxial compression tests. The calculated Weibull coefficients of uniformity are also generally in conformity with the previous data.