### Bond Work Index

The low energy crushing work index laboratory test is conducted on ore specimens larger than 50 mm, determining the crushing work index (Wi C, CWi or IWi (impact work index)). The rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 mm ( inch, the original test being developed in imperial units) to a product size of approximately 1 mm (in the original …