Comprehensive Fractal Description of Porosity of Coal of Different Ranks

Table 8

Calculation results of comprehensive fractal dimension of pore distribution of coal.

Sample number	Aperture range (nm)	𝐷𝑖	Specific surface area (m^2/g)	Specific surface area ratio (%)	𝐷𝑧
Number 1	𝑑>1000	2.8692	0.004	0.21	2.6552
	100≦𝑟≦1000	3.3146	0.095	4.94
	10≦𝑟≦100	2.6638	0.449	23.32
	2.03≦𝑑<10	2.6062	1.377	71.53
Number 2	𝑑>1000	2.9225	0.009	0.77	2.5800
	100≦𝑟≦1000	2.5088	0.081	6.89
	10≦𝑟≦100	2.6385	0.376	31.97
	2.03≦𝑑<10	2.5527	0.71	60.37
Number 3	𝑑>1000	2.7748	0.005	0.04	2.9290
	100≦𝑟≦1000	3.2303	0.039	0.35
	10≦𝑟≦100	2.9243	0.772	6.85
	2.03≦𝑑<10	2.9283	10.457	92.76
Number 4	𝑑>1000	2.3761	0.001	0.02	2.8231
	100≦𝑟≦1000	3.3543	0.017	0.3
	10≦𝑟≦100	2.8582	0.411	7.34
	2.03≦𝑑<10	2.8187	5.169	92.34

Note: the “𝐷_𝑖” is corresponding fractal dimension of 𝑖th aperture distribution segment and the “𝐷_𝑧” is comprehensive fractal dimension of coal.