A Multiscale Structural Analysis of Soft and Hard Coal Deposits in Deep High-Gas Coal Seams

Table 1

Determination of the particle size distribution of the hard coal.

No. 4 hard coal		No. 13 hard coal
Range of particle size (mm)	Mass percentage (%)	Range of particle size (mm)	Mass percentage (%)
＞50	16.56	＞50	21.78
25–50	36.46	25–50	15.31
13–25	23.97	13–25	10.78
6–13	15.58	6–13	15.02
3–6	4.60	3–6	11.99
2–3	0.80	2–3	2.47
1–2	0.98	1–2	8.70
0.5–1	0.52	0.5–1	6.47
0.25–0.5	0.27	0.25–0.5	5.03
0.125–0.25	0.15	0.125–0.25	1.88
0.075–0.125	0.11	0.075–0.125	0.47