In order to study the distribution characteristics of the three zones of spontaneous combustion in the goaf area of the gob-side entry retaining in the shallowly buried and easily spontaneous combustion coal seam,the variation laws of oxygen and temperature in the goaf area of the gob-side entry retaining were dynamically monitored by embedding high-pressure rubber hoses,high-strength steel pipe-protected optical fibers for temperature measurement,and monitoring beam tubes. With the help of numerical simulation software,the distribution range of the three zones of spontaneous combustion in the goaf area was determined. The results show that the oxygen concentration at the measurement points between the supports in the goaf area of the 31116 gob-side entry retaining shows an overall downward trend with the advancement of the working face,and the oxygen concentration at the measurement points in the return air channel is locally reversed due to the interference of air leakage at the corner. Based on the temperature measurement data of optical fibers,the temperature change cannot be used as the basis for the division of the three zones of spontaneous combustion in the goaf area of the gob-side entry retaining in Jinjie Coal Mine. Affected by the airflow migration and local air leakage,the oxygen concentration in the goaf area of the 31116 is slightly higher on the return air side than on the intake air side. Finally,it is obtained that the oxidation zone range on the intake air side of the 31116 is 140.4-313.3 m. In the middle part,the range is 201.2-351.6 m,and on the return air side,it is 153.2-328.1 m. According to factors such as the amount of residual coal in the goaf area and geological characteristics,it is comprehensively determined that the minimum advancing speed under normal production conditions of the working face is 3.3 m/d.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |