Characteristics of an Altered Diabase Dike in a Coal Seam: A Case Study from the Datong Coalfield, Shanxi, China

Table 1

VRr results and proximate and ultimate analysis data of thermally altered coal and normal coal samples.

Sample	(m)	VRr (%)	Proximate analysis			Ultimate analysis			Category
			Mad (%)	Ad (%)	Vd (%)	Cdaf (%)	Hdaf (%)	Ndaf (%)
TS1	0.1	—	3.61	58.66	11.8	75.96	2.24	0.15	Mixed coal and rock
TS6	0.1	5	8.92	60.52	9.4	79.95	2.44	0.5	Mixed coal and rock
TS7	0.8	3.74	7.94	25.48	6.33	93.76	1.16	0.55	Natural coke
TS8	2	3.72	4.8	24.43	5.6	93.84	1.6	0.97	Natural coke
TS9	3.5	1.78	1.38	54.07	10.7	78.92	4.35	1.37	Thermally altered coal
TS10	10	0.75	1.98	15.2	33.9	83.34	4.88	1.4	Normal coal
TS11	20	0.76	1.79	27.05	31.4	81.97	4.48	1.34	Normal coal

: distance to intrusion; M: moisture; A: ash; V: volatile matter; Ad: air-dried basis; d: dry basis; daf: dry ash-free basis.