Effect of Acid and Alkaline Environment on Dynamic Strength and Porosity Characteristics of Bursting Liability Coal

Table 3

Dynamic tensile strength and its deterioration of coal samples.

pH	Types of coal samples	Number of cycles	Peak strength (MPa)	Cycle phase	Total deterioration (%)	Average deterioration of each stage (%)
7	Strong bursting liability	0	2.807	0	0.000	0.000
		1	2.647	1	5.701	5.701
		3	2.550	2	9.145	1.722
		6	2.457	3	12.470	1.108
		10	2.387	4	14.964	0.624
	No bursting liability	0	1.783	0	0.000	0.000
		1	1.617	1	9.346	9.346
		3	1.503	2	15.701	3.178
		6	1.407	3	21.121	1.807
		10	1.343	4	24.673	0.888
9	Strong bursting liability	1	2.550	1	9.145	10.512
		3	2.390	2	14.846	2.850
		6	2.285	3	18.575	1.243
		10	2.180	4	22.328	0.938
	No bursting liability	1	1.684	1	5.570	18.398
		3	1.514	2	15.103	4.766
		6	1.384	3	22.411	2.436
		10	1.300	4	27.084	1.168
4	Strong bursting liability	1	2.484	1	11.508	14.790
		3	2.254	2	19.691	4.091
		6	2.110	3	24.810	1.706
		10	2.021	4	28.005	0.799
	No bursting liability	1	1.573	1	11.776	32.345
		3	1.319	2	26.056	7.140
		6	1.154	3	35.290	3.078
		10	1.042	4	41.589	1.575