A New Method for the Measurement of Gas Pressure in Water-Bearing Coal Seams and Its Application

Table 1

Density and proximate analysis results for coal samples.

Parameters	1^# coal	2^# coal	3^# coal
Proximate analysis
Total moisture (, %)	0.9	2.7	2.7
External moisture (, %)	0.3	0.9	0.8
Inherent moisture (, %)	0.6	1.8	1.9
Ash content (, %)	27.73	11.80	6.80
Volatile (, %)	18.41	34.54	36.86
Total sulfur (, %)	0.51	0.48	0.90
Density
True relative density (g/cm^3)	1.62	1.42	1.37
Apparent relative density (g/cm^3)	1.58	1.39	1.32