Research Article
Application and Development of an Environmentally Friendly Blast Hole Plug for Underground Coal Mines
Table 7
Main test parameters between traditional clay stemming and new plug.
| | Items | 2415 roadway | Return entry | | Clay stemming | Plug | Ratio | Clay stemming | Plug | Ratio |
| | Hole depth (m) | 1.8 | 1.8 | — | 2.5 | 2.5 | — | | Cycle number (number) | 31 | 31 | — | 82 | 82 | — | | Cycle charge (kg) | 21.8 | 17.0 | 128% | 96.4 | 84.6 | 114% | | Footage driving cycle (m) | 1.50 | 1.63 | 92% | 2.2 | 2.4 | 92% | | Unit explosive consumption (kg/m3) | 1.41 | 1.01 | 140% | 1.98 | 1.59 | 125% | | Blast hole utilization factor (%) | 83.3 | 90.5 | 92% | 88.0 | 88.9 | 99% | | Cyclic block number (piece) | 8.4 | 2.8 | 300% | 9.2 | 3.3 | 279% | | Half-hole marks (strip) | 2.5 | 8.3 | 30% | 3.8 | 8.9 | 43% | | Cyclic over excavation (cm) | 5.1 | 4.2 | 121% | 6.3 | 4.8 | 131% | | Dust concentration (mg/m3) | 336 | 228 | 147% | 456 | 387 | 118% | | Harmful gas content (L/kg) | 38 | 33 | 115% | 34 | 31 | 110% | | Blockage cost (RMB/m) | 16.00 | 16.63 | 96% | 28.64 | 37.58 | 76% |
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Ratio, the ratio of clay stemming to plug.
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