Study on the Mechanism of Gas Ignition by Friction Effect of Hard Quartz Sandstone Instability

Table 2

Gas ignition results of hard sandstone friction test.

Number	Specimen number	Friction velocity (m/s)	Gas concentration (%)	Test results	Number	Specimen number	Friction velocity (m/s)	Gas concentration (%)	Test results
1	1-1	1.99	11.9	Unexploded	13	1-1	6	10.3	Explosion
2	1-2	2	10.2	Unexploded	14	1-1	6	8.6	Explosion
3	1-1	4	10	Explosion	15	1-2	6	7.7	Explosion
4	1-1	4	6.8	Unexploded	16	1-2	6	9.1	Explosion
5	1-2	4	10.1	Explosion	17	1-2	6	10.5	Explosion
6	1-2	4	6.6	Unexploded	18	1-2	6	12.8	Explosion
7	1-3	4.02	10.5	Explosion	19	1-3	7.99	10	Explosion
8	1-3	5.94	6.5	Explosion	20	1-1	8	12.4	Explosion
9	1-3	5.98	9.7	Explosion	21	1-2	8	10	Explosion
10	1-1	5.99	10.5	Explosion	22	1-3	9.96	9.8	Explosion
11	1-1	6	6	Unexploded	23	1-1	10	10.9	Explosion
12	1-1	6	12	Explosion	24	1-2	10	9.9	Explosion