The Hardgrove Grindability Index is a measure of coals resistance to crushing. Grinding studies, and the resulting HGI, allow many different types of coal users to evaluate how coals will perform in their mills, allowing them to estimate grinding power requirements and throughput capacities.
Hardgrove index and brittleness test can be carried out easily on only those ores or rocks or materials, which are soft, friable and brittle 1 3. Indices with which the crushing resistance or the grindability in a wide meaning is expressed include the Rittinger number, crushing resistance, Hardgrove index and Bond work index.
Correlation between the experimental and estimated values of the Bond grindability index. grindability were in agreement with the actual values. Furthermore, more harmonious results can be obtained using the average relative densities and porosity.
to find out the grindability index termed as Statistical Grindability Index from that equation correlation coefficient of this relationship achived 0.93 ³. Ural. et al, E. Jorjani et al and H.B. Vuthaluru studied the effects of mineral matter content and elemental analysis of coal on HGI Turkish, Kentucky and Australia coals ...
Grindability index of coal is usually determined by Hardgrove Grindability Index . The correlation between the proximate analysis of Chinese coal and HGI was studied. It was found from statistical analysis that, the higher the moisture and the volatile matter content in coal, the less the HGI will be.