The Porosity Dynamic Model of the Compacted Broken Coal

Table 4

The gradation and fractal dimension under special axial pressure.

Loading of coal sample	Particle size (mm)	d ≤ 0.3	d ≤ 0.6	d ≤ 1	d ≤ 3	d ≤ 6	d ≤ 10	d ≤ 15	Fractal dimension
1#	Underscreening quality	0.133	0.277	0.399	0.646	0.86	1.075	1.239	2.5064
9 MPa	Mass ratio	0.107	0.224	0.322	0.521	0.694	0.868	1
2#	Underscreening quality	0.138	0.266	0.38	0.631	0.846	1.045	1.225	2.5054
12 MPa	Mass ratio	0.113	0.217	0.310	0.515	0.691	0.853	1
3#	Underscreening quality	0.178	0.325	0.448	0.707	0.932	1.144	1.289	2.5531
15 MPa	Mass ratio	0.138	0.252	0.348	0.548	0.723	0.888	1