Table 3 Ratio of similar materials in each coal seam.
From: Hydraulic horizontal slit-stress synergistic unloading fracturing in coal seams
Rock stratum | Thickness/cm | Proportion number | Sand | Lime | Gypsum |
|---|---|---|---|---|---|
Argillaceous siltstone | 40 | 555 | 5 | 0.5 | 0.5 |
No. 9 seam | 27 | 764 | 7 | 0.6 | 0.4 |
Argillaceous siltstone | 9 | 555 | 5 | 0.5 | 0.5 |
Limestone | 8 | 537 | 5 | 0.3 | 0.7 |
Fine sandstone | 16 | 337 | 3 | 0.3 | 0.7 |
