Hardgrove Grindability Index ( HGI ) from the experimental values of mass of the coal particles over 75-micron sieve has been introduced. Minor modifications have also been made in the diameter of the steel balls used between the grinding bowl and ring to align the dimension with

The Hardgrove Grindability Index (HGI) is a measure of coal’s 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 Grindability Index (HGI) The Hardgrove Grindability Index (HGI) is a measure of coal's resistance to crushing. Read more. 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 grindability index (HGI) measures the grindability of coal and is a qualitative measure of coal. It is referred to in mining, beneficiation and utilization of coal.

5.1 The HGI is used to predict the ranking of raw petroleum cokes or calcined petroleum cokes in industrial size mills used for crushing operations. The rankings are based on energy required and feed rate or both.

9/1/2019 · Coal samples (HGI values determined previously) was ground with a ring mill (See details in Material and Method) and the sieve analysis was carried out on the ground products. In order to address coal grindability and the energy of comminution, i.e. specific energy of grinding, the corresponding size parameter results of PSD were deeply analyzed.

hardgrove grindability index li ne The Hardgrove Grindability Index (HGI) 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.

The HGI value is determined by the given experimental formula [21] : HGI = 13 + 6.93W (1) where: W is weight of the test sample passing through 75μ sieve after grinding in the HGI machine.

The Hardgrove Grindibility Index (HGI) of coal is an indicator of its grindibility characteristics to determine the energy required for its pulverization.

The results of these experiments showed that the mills preferentially ground the higher-HGI subbituminous coal. Measuring the calorific value of the screen fractions showed that the subbituminous coal typically reported to the finer fractions (+200 mesh, +400 mesh, and –400 mesh) and the bituminous coal typically reported to the coarser fractions (+50 mesh and +100 mesh).