HARDGROVE GRINDABILITY INDEX OF PETROLEUM COKE: ASTM D5003
EXPLANATION
Hardgrove Grindability Index (HGI) is a commonly done test on coal samples (See Test Method ASTM D409). With the introduction of petroleum coke in the coal market, it has become necessary to extend this test to the former. The HGI is used to predict the ranking in industrial size mills used for crushing operations. The rankings are based on energy required and feed rate, or both. The HGI is also used to select raw petroleum cokes and coals that are compatible with each other when milled together in a blend so that segregation of the blend does not occur during particle size reduction.
TEST SUMMARY
The sample of petroleum coke is crushed to produce a high yield of particles passing a 1.19-mm (No. 16) sieve and retained on a 0.59-mm (No. 30) sieve. These particles are reduced in the hardgrove grindability machine according to the Test Method D 409. The quantity of particles retained on a 0.074-mm (No. 200) sieve is used to calculate the HGI of the sample.
TEST PRECISION
The precision data for this test is being developed.
This procedure has no bias. Both this test method and Test Method ASTM D409 produce the same results on petroleum coke samples.
