According to the general law of water permeability, the higher the water head in the water accumulation area, the higher the pressure. Therefore, when dealing with the water with high head water, it is necessary to adopt a method of turning the water into several sections for a period of time. Discharge water. The method of “segmented down-draining water” is now widely used to avoid the risk of the coal wall being crushed in one treatment. Practice has proved that all the old air and fault cracks that intersect with the upper and lower catchment areas on the ground and supply water sources must have water. Therefore, when encountering old air, faults, cracks and boreholes with recharge water sources, special Be vigilant and use careful waterproof measures to prevent water penetration. Mine permeable water has a harbinger in advance, and it can be identified according to eight different permeable symbols to see if it is permeable to water.

(1) Moisture: Coal itself is impervious to water, but when it is subjected to a certain pressure of water, some water will still be immersed in the coal. Therefore, when faced with the mining work near water area, you will find damp phenomenon local or large area, such damp phenomenon is not entirely due to the proximity of the area because of water encountered slate bottom layer is permeable rock, It is also often caused by the tide of coal.

(2) Sweating: When the working surface is close to the water-storing area, it is like the sweating of people through the coal layering, jointing, and water passing through the coal wall and gathering into water balls. It must be pointed out here that the above two symbols, whether it is tidal or sweating, sometimes have illusions. The true and false of this tidal and sweating are often identified by the method of “shallow skinning”, which is the coal face that will swell or sweat. Strip a thin layer and observe if the newly exposed coal seams are also tidal. If it is tidal, it is a symbol of water permeability.

(3) Running water or dripping water: This phenomenon is the result of further development of sweating, which proves that the distance between the working place and the stagnant water area is getting closer and closer. It also proves that the water-proof coal wall is getting softer and the water-tightness is getting worse. The ability to withstand pressure is getting less and less, and the overall situation is getting worse. At this time, we must be vigilant and step up.

(4) Hanging red: This phenomenon is often caused by the phenomenon of running water. This phenomenon indicates that the water contains iron oxides, or sulphur iron minerals , etc., and the appearance of "hanging red" is generally considered to be a symbol of close to the old water.

(5) Air cooling: After the working surface is close to a large amount of water accumulation area, the temperature of the working surface is lowered and it feels cold.

(6) Odor of hydrogen sulfide increase: as hydrogen product gas is the old empty area. Therefore, when the working surface is close to the old empty area, sometimes the smell of hydrogen sulfide - the smell of pungent rotten eggs - can cause rapid death.

(7) Water Call: There are generally two kinds of sounds: one is: the sound of “嘶嘶”, which sounds like a deep thunder or a non-boiled sound, because the water level has changed or is being rolled by rocks. The result of the impact of the impact.

(8) The bottom of the hole is soft or effluent. When using a water drill or a drill to probe the water, if the bottom of the hole is found to be soft and the drill cuttings are tidal, it means that the drill is reaching the water accumulation area. If the drilling continues, there is water. The above phenomena are all signs of close to the stagnant water area (or the old air). Special attention should be paid to taking measures to prevent the water from accumulating and causing harm.

There are several ways to identify old empty water: use a finger to rub the water to stimulate the sense of lubrication; use the nose to smell rancid; sometimes mixed with the smell of rotten eggs, chewing with astringency; with decaying sediment and suspended matter When it is observed in detail, it will find that its transparency is low; when it is analyzed, the oxygen consumption is large, and the more oxygen is consumed when the organic matter is oxidized, the more organic matter is proved.

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