
Crushing_
Crushing or Impact Work Indices are measured in the laboratory using a special impact strengthtesting machine. Some typical values for crushing work indices are listed below: Material Crushing Work Index Basalt 22 Clay 8 Coal 13 Copper Ores 14 Gold Ores 16 Glass 3 Iron Ores 17 Limestone 13 Quartz 14 _____ If the work index of the ore is known ...