Blasting the coal mine, the mine is a special safety explosives, electric detonators loaded lay blasthole, a line connected to the pin with a non-electric detonator fixed line (bus blasting), a blasting machine is turned on, electric power by supplying electric detonators Explosives are used to reach the process of crushing coal and rock mass. For various reasons, after the power is released, the detonator and the explosive will not explode or the detonator will explode and the explosive will not explode. The blind cannon, also known as the "cannon", refers to the unexploded drug hole after the industrial detonator in the detonated medicine roll is fired, energized or detonated. It is a relatively difficult problem encountered in coal mine operations. On the one hand, it poses a major threat to the safety of underground construction workers, because the treatment of blind cannons alone is a highly dangerous and laborious task. In particular, the state regulatory authorities are now very tight on coal mine safety, ensuring that "people-oriented, On the other hand, the existence of blind cannons has a very negative impact on the production itself, but it has a negative impact on the blasting effect, but the entire blasting construction operation fails, reducing production efficiency and increasing The consumption of blasting equipment . Blasting construction is an important part of coal mine production. Its purpose is to carry out roadway excavation and provide suitable excavation materials for subsequent mining and transportation. However, for various reasons, blind cannons have always been a shadow of blasting construction, especially underground coal mine construction. Therefore, it is particularly important to analyze the causes of blind cannons and propose reasonable prevention measures. 2. Reason analysis: The cause of the blind gun accident is multi-factor, mainly the following: 2.1 Quality of blasting equipment (1) The slamming of the electric detonator is not up to the requirement, the explosive charge cannot be induced, or the quality of the electric detonator itself is defective, resulting in failure to initiate the explosion itself. (2) Explosives will not be detonated if they are wet or otherwise. The distribution ratio of explosives is unreasonable, or there are problems in the manufacturing process of explosives, which affects the technical performance of explosives. In severe cases, it will produce a blast. 2.2 Blasting construction (1) When processing the detonating equipment, there is no tight connection between the detonator and the explosive, which is easy to fall off. If the detonator is detached from the explosive, the detonation wave cannot be effectively transmitted between them, resulting in a blind cannon. (2) In the case of large blasting scale and relatively complicated network, due to the high construction intensity, local blastholes or individual detonators may be missed or misconnected, which may also cause blind cannons. 1.1 Explosive material problem At present, the explosive materials used in coal mines are mainly coal mine-type electric detonators and explosives. 1) The main problems related to detonators are: 1 the quality of the detonator (such as bridge wire false welding, unqualified resistance, etc.) causes excessive resistance or instability, or even open circuit, so the power is poor or non-conducting; 2 improper storage or use, The detonated medicine head is damp, deteriorated, the bridge wire is rusted, etc., causing the detonator sensitivity to drop sharply and fail to detonate; 3 mixing detonators of different manufacturers, different specifications and different materials. Because of the mixed electric detonator, the resistance difference is large. According to the 楞-Joule law, in the series electric blast network, as long as the bridge wire resistance is different, the igniting heat cannot be completely consistent, even if the resistance is the same or similar, the electric igniting The characteristics will not be the same, which is easy to cause a gun. 2) The main performance of the explosive problem: 1 The use of damp and hardening metamorphic explosives, so that the detonation sensitivity and detonation stability are reduced, so that the drug roll does not explode; 2 when using ordinary ammonium nitrate explosive, it is easy to make the mining face due to on-site construction reasons. The distance between the blastholes is too small, and the time difference between the detonators and the detonation is too large, which may cause the first blasting blast to “squeeze†the explosives in the adjacent blastholes. 3 In the wet and watery working conditions, non-water resistant explosives are used, or Water-resistant explosives are not covered by waterproof jackets or waterproof sleeves, and there is pulverized coal and rock powder between the medicine rolls, which causes the explosives to refuse to explode. 1.2 Operational process problems 1) In the blasting network, the wiring between the foot line and the foot line, the foot line and the connecting line, and the connection between the connecting line and the firing bar is virtual, thereby increasing the resistance of the joint and affecting the conduction of the joint, so that the ignition energy of the detonating detonator is too small, and it is difficult to Detonation and refusal. At the same time, due to negligence of work, it may also cause the network part of the wiring to be leaked and form an open circuit; 2) The exposed joints or damaged parts of the network are in contact with external conductors and wet objects, causing leakage, which causes the detonators to not explode; 3) When charging and filling the mortar, if the operation is not carried out according to the regulations, the medicinal force is too large with the gun stick, and the explosive is compacted, so that the sensitivity is lowered; 4) The detonator foot line is cut off or the insulation is damaged, causing the open circuit or leakage to prevent the detonator from exploding. The exposed joints of the detonator line are in contact with each other to cause a short circuit and the detonator does not explode; 5) Due to improper operation, the position of the detonator in the drug introduction is unreasonable or the detonator in the drug is removed from the original position, causing the explosive to not explode; 6) The design of the blasting network is unreasonable, and the number of connected detonators exceeds the detonating capability of the detonator. 1.3 explosion power problem The blaster fails and the power is insufficient, so that the current in the local network is less than the quasi-explosive current of the detonator, causing the detonator to not explode. 2 shotgun prevention 1) The shooting tool should maintain good performance. Before use, it is necessary to inspect and maintain the blasting device and the firing bar. Unqualified shooting tools are not allowed to be distributed and used. It is necessary to pick up the shift, prevent collision, beat, and replace the battery in time. It is strictly forbidden to check the residual current with the short circuit of the terminal and the spark; the detonating capacity of the detonator is slightly larger than the number of shots. 2) Strict explosive material storage management system and detonator test and explosive inspection and acceptance system. Do not issue and use metamorphic explosives and unqualified detonators. Detonators of different manufacturers and different specifications shall not be blended. Do not use the instant detonator as a one-millisecond detonator. use. 3) Charge and connect according to the regulations. When charging, the gunman should pull the straight line of the detonator and use a wooden gun to gently feed the medicine into the blasthole to prevent the foot line from being broken or smashing the insulation of the foot line. At the same time, the medicine roll in the blasthole should be in close contact. To ensure good detonation. When performing the connection between the blaster and the busbar, the busbar and the footline, the footing and the footing, the blaster's hand should be washed and dried before the terminal is tightened. The network connector connection does not need to be left or not, and the rust of the foot line connection should be scraped, and the connector should be suspended. If the busbar is not long enough, the busbar of the same specification should be connected. The connecting cable should be the same as the footing of the detonator in the network. Do not change the connection method. After the connection, carefully check to avoid misconnection, leakage, and connection. After that, the total resistance of the network should be measured. 4) Do a good job in the management of on-site blasting equipment. The blasting equipment box should be stored in a safe and dry place without dripping water. It is not allowed to open and tear off the outer packaging of explosives. 3 gun treatment In actual work, if you encounter a gun, you should analyze it carefully, find the cause, and take effective measures to eliminate it. When the squadrons are on duty, they must do a good job. The following methods should be used when handling shotguns. 1) Due to the bad connection caused by the connection, you can re-link and release. 2) If the re-linking does not sound, you can make another new blasthole parallel to the rifle at least 0.3m away from the rifle, and re-charge the gun. 3) After re-opening the charge and releasing the gun, the gunner must inspect the coal and vermiculite of the explosive and collect the unexploded electric detonator. It is strictly forbidden to use the planer or remove the originally placed explosives and detonators from the blasthole. It is strictly forbidden to continue to deepen the residual holes of the blasthole. It is strictly forbidden to use the eye-catching method to poke the medicine out. It is strictly forbidden to blow these blastholes with the pressure wind. This is because detonators and explosives are chemical substances that are temporarily relatively stable. Under the influence of the outside world, their stability is destroyed, chemical reactions are rapidly carried out, and finally an explosion is caused. Therefore, detonators and explosives have certain sensitivity to impact, friction, sparks, stray current, and high temperature. Using the planer or removing the original placed lead from the blasthole and pulling the detonator out of the medicine will cause it to be impacted. The high-sensitivity detonation in the detonator will cause friction with the inner wall of the tube and cause the detonator to explode. Pulling out the electric detonator will detonate due to the stray current in the mining face. This is also the case for collecting unexploded detonators in blown coal and meteorites after shooting. It is strictly forbidden to use the method of eye-catching to poke the medicine outside. The pressure of the blasthole is caused by the pressure of the blasting of the explosive. Therefore, at any place in the coal mine, each time a gun is fired, the gun smoke is dissipated, and the gunner must be in the roof of the roadway. Under the safe conditions of the bracket without collapse, first check the blasting site for the gun. If a rifle is found, it should be handled in time under the guidance of the squad leader. It is strictly forbidden to carry out and handle the rifle at the location before the treatment is completed. Running Shoes,Red Running Shoes,Good Running Shoes,Kids Running Shoes Shangqiu JIAYING SHOES CO.,LTD. , https://www.jiayingshoes.com
Preventive measures for accidents of underground cannons (barrel guns)
1 Introduction: