2. CO AL MILL MODELING The MPC con troller for coal mills is based on a nonlinear ph ysical mo del to describ e the grinding, drying, and separation pro cesses o ccurring in typical coal mill pulv erizers. Similar mo dels ha ve b een describ ed b y F an and Rees [1994], Zhou et al. [2000] and Niemczyk et al. [2009]. Grinding : The grinding pro ...