a grinding mill in which the material to be ground is tumbled in a drum with heavy balls of iron, steel, or stone.
Origin of ball mill
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
engineering a horizontal cylinder or cone in which a substance, such as a mineral, is ground by rotation with steel or ceramic balls
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012