Knowledge of the grindability behavior of solid materials can be considered as an important factor for the design of their grindability systems. Bond work index (Wi) can be considered as one of the most important affecting factors in the design of grinding systems which express on the value of energy (kwh) consumed per ton of the ground ore.
In this research the Bond work index (Wi) is appointed using the standard Bond test and Karra's and Kapur's abbreviated algorithm's for some Egyptian ores which can be used in some strategic industries such as ceramics and cement.
These ores include quartz, white marble, Nephline syenite, cement clinker, kaolin, ilmenite and barite. Experiments are carried out at different percentages of ore filling ratio and different test sieve aperatures.
The study cleared that, Values of the Bond work index (Wi) resulted from the three mentioned methods are quite similar. It is shown also that the filling ratio affects greatly on the value of the work index. The index value increases by decreasing the test screen aperture (degree of fineness).
It is recommended to identify each of the filling ratio and degree of fineness for appointing the work index as a pre request for the design of grinding systems.