Experimental Research into the Efficiency of an Electromagnetic Mill

This paper presents a method for quantitative assessment of the efficiency of an EMM, taking into consideration its design parameters (dimensions, winding data, etc.) and technological indicators of the milling process (mass of the milled substance, mass of the mill, milling time, etc.). The performance of an EMM is characterized in terms of two indicators-the efficiency of the milling itself, and its quality. The EMM efficiency was expressed as the ratio of the ground mass to the time taken for the grinding, and the grinding quality was given as the ratio of the mass of the smallest fraction obtained as a result of grinding to the total ground mass. Those indicators were calculated on the basis of the analysis of empirical results obtained using an EMM comprising a rotating magnetic field. The efficiency and quality of grinding were taken into account to determine these indicators. Moreover, a deterministic relation was established between this efficiency and quality of milling and the calculation values-the average number of millstone impacts and average impulse magnitude of ground material impacts, calculated using mathematical modelling of the grinding process. An algorithm applicable for determining the performance of the EMM and the quality of grinding was proposed on the basis of the results of this research.