Ball mill | device | Britannica
#0183;#32;Other articles where Ball mill is discussed: explosive: Manufacture of black powder: this device is called a ball mill. The saltpetre is crushed separately by heavy steel rollers. Next, a mixture of several hundred pounds of saltpetre, charcoal, and sulfur is placed in a heavy iron device shaped like a cooking pan. There it is continuously turned over by devices called plows,