“…In grinding processes, energy consumption is a very important profitability criterion for the applied particular size reduction technology. The energy consumption of grinding is the subject of many studies, especially in the case of ball mills for grinding clinkers [8,9], fuels [10], iron ore [11], hematite ore [12], sulfide ore [13], wet ores [14], and in the case of stirred mills for grinding ores [15][16][17] and wet quartz [18]. In [19,20], the energy efficiency of various coals grinding in the ball-and-race mills is studied experimentally.…”