What are the signs of mine permeability, and what are the main signs of mine permeability?

There are several main signs before the mine is flooded:

1. Hanging sweat. The phenomenon that the water in the stagnant water area coalesces into many water droplets on the coal and rock wall of the mining face through the cracks of the coal and rock under its own pressure, which is called hanging sweat. When the moisture in the underground air encounters the low temperature coal, it may sometimes coalesce into many water droplets.

The way to distinguish between real and fake hanging sweat is to carefully observe whether the newly exposed coal wall is damp, if it is damp, it is a sign of water permeability.

2. Hang red. When the oxide containing iron in the mine water penetrates into the surface of the coal mass of the mining face through the cracks in the coal and rock, it will show dark red rust, which is called hanging red. Hanging red is a signal of water out.

3. Water calling. When the high-pressure water in the aquifer or water accumulation area is squeezed into the cracks of the coal wall, it will make a "hissing" sound when it rubs against the two walls, which indicates that the mining face is very close to the water accumulation area or other water sources.

4. The air becomes colder. When the mining face is close to the waterlogged area, the air temperature will drop, the coal wall will be cold, and people will have a cool and cold feeling as soon as they enter the working face; However, it should be noted that the temperature of groundwater in mines that are greatly affected by geothermal heat is high, and the temperature rises when the mining face is close to the waterlogged area.

The main signs of mine permeability are:

1) Hang red. The oxide containing iron in the mine water will show dark red rust when it penetrates into the surface of the coal mass of the mining face through the cracks in the coal and rock, which is called hanging red. Hanging red is a signal of water out.

2) Hang sweat. Under the action of its own pressure, the water in the water accumulation area forms many water droplets on the coal rock wall of the mining face through the cracks in the coal and rock.

3. Water calling. When the high-pressure water in the aquifer or water accumulation area is squeezed against the coal rock fracture, it will make a "hissing" sound when it rubs against the two walls, which indicates that the mining face is very close to the water accumulation area or other water sources.

4. The air becomes colder. When the mining face is close to the waterlogged area, the air temperature will drop, the coal wall will be cold, and people will have a cool and cold feeling as soon as they enter the working face;

5) Fog appears. When the temperature of the mining face is high, the stagnant water seeping out of the coal wall will evaporate and form a mist.

6) The roof is watered and increased; The top plate is pressed, and the bottom plate is bulging.

7) The water is mixed and smelly.

8) The harmful gases in the mining face increase. Harmful gases such as gas, carbon dioxide, and hydrogen sulfide are emitted from the stagnant water area.

9) Cracks appear to seepage, etc. If the water is clear, it is far away from the stagnant water area; If it is turbid, it is close to the waterlogged area.

Signs of mine permeability:

1. The coal seam is damp and dark. Due to the infiltration of water, the coal seam becomes moist and the luster darkens. If this is still the case after digging a layer, it means that there is standing water nearby.

2) Hang sweat. When the mining face is close to the waterlogged area, the water will gather into a lot of water droplets on the coal wall and rock wall through the coal and rock fracture surface under its own pressure, and the phenomenon of hanging sweat will appear.

3. Hang red. When the oxide containing iron in the mine water penetrates into the surface of the coal mass of the mining face through the cracks in the coal and rock, it will appear dark red water rust, which is called hanging red.

4. Water calling. When the high-pressure water in the aquifer or water area is squeezed into the cracks in the coal wall, it rubs against the two walls to make a "hissing" sound, which indicates that the mining face is very close to the water accumulation area or other water sources.

5. The air becomes colder. When the mining face is close to the waterlogged area, the air temperature will drop, the coal wall will be cool, and people will feel cool and cold when they enter the working face.

6. Fog appears. When the temperature of the mining face is high, the stagnant water seeping out of the coal wall will evaporate and form a mist.

7. The roof is drenched with water, or the pressure head appears.

8. The top plate is pressed, and the bottom plate is bulging.

9. The water is muddy and smelly.

10. The smell of hydrogen sulfide increases. Harmful gases increased in the excavation face, and harmful gases such as gas, carbon dioxide and hydrogen sulfide were emitted from the water accumulation area, and hydrogen sulfide smelled of rotten eggs.

11. Water seepage appears in the fissure. If the effluent is clean, it is far away from the stagnant water area; If it is turbid, it is close to the waterlogged area.

12. The bottom of the borehole is soft or watery.

When using a dipper or drill to explore the water, if it is found that the bottom of the borehole is soft and the drill cuttings are damp, it means that the drill is about to reach the water accumulation area, and if you continue to drill, there is a possibility of water.

There are generally some signs before the coal seam or rock formation is permeable. Underground workers should be familiar with the warning signs before the occurrence of water penetration accidents, so that preventive measures can be taken in time. The signs before water penetration are often as follows:

1. The coal seam is damp and dark. Due to the infiltration of water, the coal seam becomes moist and the luster becomes dull. If this is still the case after digging a layer, it means that there is standing water nearby.

2) "Hanging sweat" on the roadway wall or top wrench, which is a phenomenon of condensation on the surface of the rock (coal) wall when the water passes through the tiny cracks in the rock.

3) The coal seam cools. When the coal seam is watery, it can absorb the heat of the human body, and it will feel cold when touched by hand, and the longer the hand is placed, the cooler it feels.

4) The top plate of the working face is drenched with increased water, or there is a pressure head.

5) The temperature of the working surface is reduced. A faint mist can be seen on the work surface, which makes people feel cool.

6) Water called. The "hissing" sound of water squeezing out of the cracks in the coal seams, and sometimes the sound of muffled thunder or boiling water can be heard, which is a dangerous sign of water penetration.

7) The harmful gas on the working face increases. Due to the gas emitted out of the water accumulation area, the content of carbon dioxide, hydrogen sulfide and other gases in the air of the working face increases significantly.

8) The coal wall or roadway wall is "hung red". For example, old empty water generally accumulates for a long time and has little water supply, which is usually called "dead water", so the acidity is large, and the water contains iron-containing oxides or sulfide minerals, which is a sign of close to old empty water.

Not all of the above signs appear before water penetration every time, and sometimes one or several may be found, and in rare cases, they may not even appear. Therefore, it is necessary to be vigilant, closely watched, and carefully analyzed. This is of vital importance for timely disaster prevention and mitigation measures.

The mine is permeable to indicate that the coal wall is "hanging red", the coal wall is "hanging sweat", the air is cold, fog appears, the "hissing" water is called tomorrow morning, the bottom plate is bulging, the water color is muddy, the smell is stinking, the top water is increased, and the piece of water is rising.