Mine blasting safety knowledge
New technology: O2 rock demolition system
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Blasting engineering is a technology that uses the huge energy released instantly by the explosion of explosives to destroy the medium around the explosives or deform it, thereby achieving certain engineering purposes. In mining engineering, drilling holes in ore or rock is called rock drilling, and loading explosives into the holes to break the ore or rock from their parent body is called blasting. Mining blasting engineering is the technology of using explosives to break rocks and ores.
1. Overview of mining blasting
(1) Basic theory of explosion
Mining blasting uses industrial explosives to break, compact, and loosen the objects being blasted, which is a chemical explosion. The formation of a chemical explosion must meet four conditions at the same time: the explosion reaction process must release a large amount of heat energy; the chemical reaction process must be high-speed; the chemical reaction process should be able to generate a large amount of gas products; and the reaction can propagate itself.
There are four basic forms of explosive chemical reactions: thermal decomposition, combustion, explosion, and detonation. These four basic forms are closely related and can be transformed into each other under certain conditions. People can control external conditions and "control" the chemical reaction of explosives as needed.
(2) Commonly used explosives in mines
Explosives are compounds or mixtures that can undergo rapid chemical reactions under certain conditions, release a large amount of heat, and produce a large amount of gas, thereby exerting a strong mechanical effect on the surrounding medium and presenting the so-called explosion effect. For example, 1000g of ammonium nitrate explosives only takes 0.3 millionths of a second to complete the explosion reaction, can generate 4.18MJ of heat, and the temperature during the explosion reaches 2000~3000℃. At the moment of explosion, the solid explosive quickly turns into gas, and its volume increases by 850~950 times compared with the original volume.
According to their composition and structure, explosives can be divided into two categories: monomer explosives and mixed explosives; according to their use and characteristics, they can be divided into several categories such as detonators, high explosives, gunpowders, and pyrotechnic agents. The explosives used in mines in my country include ammonium nitrate explosives, nitroglycerin explosives, and emulsion explosives. Ammonium nitrate explosives are mixed explosives with ammonium nitrate as the main component. Commonly used ammonium nitrate mixed explosives include ammonium antimony explosives, ammonium oil explosives, and aqueous ammonium nitrate explosives.
(3) Explosive equipment and detonation methods
Explosive detonation refers to the detonation of explosives by detonating explosive equipment.
Depending on the type of detonating equipment used, the corresponding detonation methods include fire detonator detonation, electric detonator detonation, detonating cord detonation and detonating tube detonation.
④ The carriage should be guarded day and night, and the parking location should ensure the safety of the operation point, manned buildings, important structures and equipment. It is allowed to measure electric detonators and process detonating tubes 50m away from the special carriage.
• Storing explosive equipment on a ship
When storing explosive equipment on a ship, a danger sign should be hung on the ship and a red light should be hung at night. There should be guards and the ship should be moored in a safe place outside the route, not less than 250m away from the dock, buildings, other ships and blasting operation points; when docked, no unrelated personnel are allowed to enter the shore within 50m.
The ship should be equipped with separate explosive compartments and detonator compartments, each with separate entrances and exits and separated from the engine room and heat source; the storage volume shall not exceed 2t; the frame for storing explosives shall be provided with flanges, and the boxes (bags) containing explosives shall be firmly fixed.
Fireworks are strictly prohibited on board, and sufficient fire-fighting equipment shall be available; only mobile battery lights or safety flashlights are allowed for lighting.
• Temporary open-air stacking
Under special circumstances, explosives approved by the unit security department and the local county (city) public security agency can be temporarily stacked in the open air, but the following regulations must be observed:
① The stacking site should be selected in a safe place, strictly guarded, patrolled day and night, and fireworks are strictly prohibited within 100m around, and no debris shall be stacked on the site.
② Explosives should be stacked on wooden pallets. It is prohibited to stack them directly on the ground, and the upper part should be covered with canvas or a simple tent.
③ It is strictly prohibited to mix detonators with explosives. The distance between the explosives pile and the detonator shall not be less than 25m.
• Temporary stacking at the work site
Explosive materials transported to the work site should be supervised by a dedicated person and marked with eye-catching signs (red flags during the day, red lights at night in the mine or in the open air). Explosives and detonators must not be mixed, and detonators must not be mixed with explosives. The stacking amount must not exceed the amount used during the shift. In case of large-scale blasting, the amount of explosives required for this project can be stored. During demolition blasting, seismic exploration and oil and gas well blasting, it is prohibited to scatter blasting equipment on the ground. Detonators should be placed in wooden boxes wrapped with iron sheets and locked.
(2) Transportation of blasting materials
• External transportation of enterprises
When transporting blasting materials outside the enterprise, attention should be paid to the transportation certificate of explosives, transportation equipment, loading and unloading, driving, etc.
① Explosives Transportation Certificate. The receiving unit shall apply to the local (county or city) public security bureau for an "Explosives Transportation Certificate" based on the blasting materials supply and sales contract signed and stamped by the materials management department, stating the name, quantity and departure and arrival locations of the blasting materials. After delivery, the consignee or purchaser shall note the arrival of the goods on the transport certificate and return the transport certificate to the original issuing public security organ.
For the transportation of imported and exported explosive materials, the consignor shall apply for the "Explosive Materials Transport Certificate" from the county or city public security bureau where the consignee or exit port is located with the documents approved by the Ministry of Ordnance Industry and the import and export trade license issued by the foreign trade department.
When transporting explosive materials for short distances within the city, the "Explosive Materials Transport Certificate" can be exempted, but the public security bureau must be notified in advance and the transportation safety regulations must be strictly implemented.
② Transportation equipment. The transport vehicle and ship must meet safety requirements.
There shall be no power supply in the cabin of the motor vessel, and the steam pipe shall be reliably insulated. There shall be no gaps between the bottom plate and the bulkhead, the hatch shall be closed tightly, and the cabin partition wall adjacent to the engine room shall take insulation measures.
Before the car leaves the car, the garage director (or team leader) shall carefully check the vehicle and indicate on the car: "The vehicle has passed the inspection and is allowed to be used to transport explosive materials." It shall be driven by a driver who is familiar with the nature of explosive materials and has safe driving experience. In winter transportation in cold areas, anti-skid measures must be taken.
For transportation by tractor or tricycle, comprehensive consideration can be given to the national standard GB6722-86 "Safety Regulations for Blasting" and "Safety Regulations for Blasting in Township Open-pit Mines".
When transporting by animal-powered vehicle, the vehicle shall be equipped with brakes, and the vehicle carrying detonators shall be equipped with shockproof devices. Use trained animals, and the blasting equipment on the vehicle shall be tied tightly.
③ Loading and unloading. Loading and unloading of blasting equipment should be carried out as much as possible during the day, with special personnel on site for supervision, and guards should be provided, and no unrelated personnel are allowed to be present. At the loading and unloading site, fireworks and carrying of flammable items are strictly prohibited, and there should be obvious signals: red flags and warning signs are hung during the day, and there should be sufficient lighting and red lights at night. The stations and docks for loading and unloading blasting equipment shall be determined by the local public security organs in consultation with the railway and transportation departments, and shall be far away from the city center and densely populated areas. Loading and unloading of blasting equipment is prohibited in thunderstorm weather. When transporting from the production plant or the main warehouse to the branch warehouse, the packaging boxes (bags) and lead seals must be intact.
④ Driving. Vehicles (ships) loaded with explosives must be escorted, and non-escorted personnel are not allowed to ride. They must travel at a speed limit along the designated route and set up danger signs. At the same time, different transportation vehicles have different safety regulations during the transportation process, which must be strictly enforced.
• Transporting explosives to different blasting points
① When transporting by car or carriage, follow the relevant regulations.
② Transporting blasting equipment in vertical shafts and inclined shafts. Notify the winch driver and signalman in advance, do not transport during the concentrated time of commuters, do not stop at the wellhead room and underground parking lot, and other personnel except blasters and signalmen are not allowed to ride in the same tank; when transporting nitrate explosives in a cage, the loading height shall not exceed the edge of the carriage; when transporting nitroglycerin explosives and detonators, no more than two layers shall be used, and soft cushions must be laid in the middle; when transporting detonators or nitroglycerin explosives in a cage, the lifting speed shall not exceed 2m/s; when transporting blasting equipment with a bucket or slope winch, the speed shall not exceed 1m/s; when transporting electric detonators, insulation measures must be taken.
③ When transporting explosive materials by electric locomotive, hang "danger" signs at the front and rear of the train, separate the carriage with explosive materials from the locomotive or the carriage with detonators from the carriage with other explosive materials by carriages without explosive materials; use closed special carriages to transport explosives and detonators, the car should be padded, and the driving speed should not exceed 2m/s; reliable insulation measures should be taken when transporting electric detonators; when loading and unloading explosive materials, the locomotive must be powered off.
④ When transporting explosive materials on a ramp by car, install battery red lights at the front and rear of the car as danger signs. It is prohibited to transport when there are a lot of people going to and from get off work, and the driving speed should not exceed 10km/h. When driving in the middle of the lane, give way to other cars when meeting, and park by the side.
⑤ Manual handling of blasting materials: Explosive materials should not be collected in advance. After collecting blasting materials, they should be delivered directly to the blasting site. Explosive materials should not be carried in crowded places, and they should not be thrown or placed randomly. Explosives and detonators should be placed in two special backpacks (wooden boxes) respectively, and should not be placed in pockets. When underground or at night, you should carry a good battery lamp, safety lamp or insulated flashlight with you. One person should not carry more than 10kg of explosives and detonating materials at a time, and the unpacking (bag) of explosives should not exceed 20kg. The original packaged explosives should not exceed one box (bag) on the back, and the original packaged explosives should not exceed two boxes (bags) on the shoulder.
• Explosive materials
Commonly used detonating materials include detonators (fire detonators, electric detonators), detonating cords and detonating cords. Detonators are the main detonating materials, which can be used to detonate explosives, detonating cords and detonating cords. According to the ignition method, there are fire detonators and electric detonators.
Fire detonator is the most basic type of industrial detonator, which is directly detonated by flame. Electric detonators are divided into instantaneous electric detonators and delayed electric detonators. Delayed electric detonators are further divided into second or half-second delayed electric detonators and millisecond delayed electric detonators.
• Detonation method
There are several methods for detonating explosives: Fire detonator detonation is to use the fuse to transfer flame to detonate the detonator, and then detonate the explosive. The operation process of this detonation method includes processing the detonator, processing the detonating charge, loading the charge, and igniting the detonation; Electric detonator detonation method, after loading the charge, connect the wires and use the conduction meter to check whether the network is conductive. The electric detonators used should be tested with a conductivity meter in advance. Those with too large resistance error cannot be used. The detonating cord initiation method, also known as the detonator-free initiation method, is divided into ordinary detonating cord and low-energy detonating cord. Ordinary detonating cord is the most commonly used in non-coal mines. The detonating tube initiation method uses a detonating gun or detonator to detonate the detonating tube, detonate the non-electric millisecond detonator in the detonating charge, and then detonate the explosive.
2. Mine blasting safety technology
(1) Detonation safety technology
• Fire detonator initiation and accident prevention
① Premature explosion and prevention of fire detonator initiation
The rapid combustion or deflagration of the fuse may cause the fire detonator to explode prematurely, thus causing casualties. Strengthening the management of the manufacture, storage, and transportation of fuses and detonators and improving the quality of fuses and detonators can greatly reduce the rapid combustion, slow combustion, and refusal to burn of fuses and the refusal to explode of detonators.
To prevent the occurrence of premature explosion accidents of fire detonators, in addition to strictly ensuring the quality of the fuse, a safe ignition method should be used to detonate the fire detonator. The "Explosive Safety Regulations" stipulate that when detonating fire detonators, a centralized ignition method must be used. Centralized ignition can be ignited with ignition tools such as mother-child fuses and ignition tubes.
② Delayed explosion and prevention of fire detonator detonation
When the fuse has defects such as broken or missing medicine and the fuse is caused by external forces, it will cause delayed explosion accidents. Delayed explosion accidents are very harmful. To prevent the occurrence of delayed explosion accidents, in addition to strengthening the quality management of fuses, detonators and explosives, and establishing a sound inspection system, excessive bending or breaking of the fuse should be avoided during operation, and a special person should listen to the sound of the gun and count the guns, or the gun counter should count the guns. When there is a blind shot or there may be a blind shot, the time to enter the gun area should be doubled.
③ Refusing to explode and prevention of fire detonator initiation
It is impossible to completely eliminate the phenomenon of refusing to explode in fire detonator initiation, but active measures should be taken to reduce the refusing rate to a minimum. First, carefully select and inspect the fuse and detonator; second, properly store the fuse and detonator to prevent moisture and deterioration; at the same time, strengthen the training of blasters, improve their professional knowledge level, and improve operating techniques.
• Electric detonator initiation and accident prevention
① Premature explosion and prevention of electric detonator
Stray current, lightning and static electricity are the main factors causing premature explosion accidents of electric detonator initiation.
The main measures to prevent stray current are: using electric blasting networks that prevent stray current; using electric detonators that resist stray current; using non-electric initiation; strengthening the insulation of blasting lines, and not using bare wire connections. Lightning can detonate electric detonators by direct lightning strikes, static induction or electromagnetic induction, among which electromagnetic induction is the main one. Measures to prevent premature explosion caused by lightning include: prohibiting electric detonator blasting in thunderstorm weather; setting up a lightning protection system in the blasting area; using shielded wire blasting; using a non-electric detonation system for detonation.
Measures to prevent premature explosion accidents caused by static electricity include: increasing the moisture content of explosives; using antistatic detonators; using non-electric detonation methods.
② Electric detonator refusal to explode, delayed explosion and prevention
The reasons for electric detonator refusal to explode are: first, the detonator itself has defects, and some defects are not easy to be found when tested with a conduction instrument; second, there are mistakes in the design and operation of the detonation network.
In order to reduce the occurrence of refusal to explode, in addition to strictly testing the detonator and ensuring the quality of the detonator, it is also necessary to adopt an accurate and reliable detonation network, eliminate errors in network design, and strictly implement operating procedures. To prevent delayed explosion accidents, it is necessary to strengthen the inspection of blasting equipment, and unqualified blasting equipment is strictly prohibited from use.
③ Safety issues of detonating cord detonation
The detonators and detonating tubes in the detonating cord detonation system contain high thermal and mechanical sensitivity explosives like ordinary detonators. They should be protected from impact and friction during use. The delay effect of detonating cord detonation is much greater than that of electric detonator detonation system. Therefore, when designing the detonating cord detonation network, a ring network cannot be used, that is, the initial position and the final position of the detonation transmission cannot be too close. In the presence of gas, the use of detonating cords is prohibited.
④ Safety issues of detonating cord detonation
The main safety issue of the detonating cord network is the explosion refusal accident. The main reason for the explosion refusal problem is the incorrect connection method. Therefore, special attention should be paid to the correct connection method to prevent the occurrence of explosion refusal accidents.
(2) Safety standards and safety distances
• Earthquake safety distance
Because the earthquake safety distance is often an important factor in determining the scale and method of blasting projects, some blasting designs often encounter problems in the approval process due to the control of earthquake effects. Because the control standards and calculation methods are not very strict, and the structures and conditions of the protected buildings (structures) are very complex, how to more accurately estimate the earthquake intensity and control the degree of damage to buildings (structures) often becomes a controversial issue. The "Explosion Safety Regulations" stipulates that "the blasting earthquake safety of general buildings and structures should meet the requirements of safe vibration speed" and stipulates the control standards for the vibration speed of ground particles of buildings (structures).
•Safe distance of air shock waves
The safe distance of air shock waves is mainly determined based on the following aspects: safe distance to ground buildings; calculation and control standards for overpressure values of air shock waves; blasting noise; directional effect and atmospheric effect of air shock waves.
•Safe distance of blasting flying rocks
The flying distance of blasting flying rocks is affected by terrain, wind direction and wind force, blockage quality, blasting parameters, etc. The safe distance of blasting flying rocks should be considered separately according to the conditions of chamber blasting, non-throwing blasting, and throwing blasting.
Safety distance of electric detonation
The safety distance of electric detonation mainly considers the safety distance between the blasting area and the emission sources such as high-voltage lines, radio stations and television stations.
•Safe distance for diffusion of harmful gases from blasting
Harmful gases from blasting mainly include CO, NO, NO2, N2O5, SO2, H2S, NH3, etc., which can cause suffocation and blood poisoning. Sampling and monitoring must be carried out after a large number of blasting. Only when the concentration of harmful gases is lower than the allowable index can you go down to the mine to work. Measures to reduce harmful gases from blasting: use qualified explosives; waterproof the detonating equipment and explosives, block the blastholes, etc., to avoid half-explosion and deflagration; strengthen ventilation, pay special attention to ventilation dead corners and blind spots; ventilation must be carried out before personnel enter and sampling and monitoring of the concentration of toxic gases in the air.
•Safety standards and explosion-proof measures for gas and coal dust
Gas is a general term for harmful gases in mines, including methane, carbon monoxide, carbon dioxide and hydrogen sulfide. Measures to prevent gas ignition and explosion: prevent gas accumulation, ensure ventilation, insist on monitoring, strictly stop and evacuate according to regulations; seal the goaf to prevent oxygen from entering; arrange holes, charge, block, and detonate according to regulations, and operate correctly. Blasting to ignite gas; use explosion-proof electrical facilities and strengthen management, and strictly control stray current.
Preventive measures for coal dust explosion: comprehensive dust prevention, such as water injection of coal seams at the mining face; use water seal blasting technology, set up water spray and spray devices, use wet drilling, frequently wash the walls of the shaft and the tunnel, control ventilation wind speed, coal bunkers and chutes must not be emptied, prevent coal leakage during transportation, sprinkle water during transportation, and lay rock powder in transportation tunnels and return air tunnels. Use these comprehensive measures to reduce the concentration of coal dust in the air; prevent blasting open flames and mechanical sparks from causing coal dust explosions; pay attention to preventing mixed explosions of gas and coal dust. Measures to prevent gas explosions are also effective in preventing mixed explosions.
3. Safety management of blasting operations
(1) Safety management system for blasting operations
All blasting operations must use blasting equipment that meets national or ministerial standards. Unauthorized explosives are not allowed to be used.
Group mining sites and mining sites that carry out blasting operations must have a blasting supervisor, blasters, and blasting equipment custodians. These personnel should understand the performance of the blasting equipment used, blasting techniques, and relevant safety knowledge.
All personnel engaged in blasting work must undergo training and examinations and obtain a "blaster's license" issued by the local county public security department before they are allowed to carry out blasting operations.
(2) Safety regulations for blasting operations
• Processing of detonating equipment
Processing of detonating tubes and signal tubes should be carried out in a dedicated room in the blasting equipment storage area. It is strictly prohibited to carry out processing in blasting equipment storage rooms, residences, and blasting operation sites.
During processing, they should be handled with care to prevent them from falling or being stepped on. Fireworks are prohibited. They should be placed in a covered wooden box while being processed. No more than 100 detonators should be stored at the processing site.
A sharp knife should be used to cut the fuse or detonating tube. 5cm should be cut off from both ends of each coil of fuse or each roll of detonating tube. When cutting fuse or detonating tube, it is strictly forbidden to pile up detonators on the working surface. Before cutting, the appearance should be carefully checked. Any parts that are too thick, too thin, broken or have other defects should be cut off.
Before assembling living tubes and signal tubes, the appearance of detonators must be checked one by one. Any tube that is flattened, damaged, rusted, has a skewed reinforcing cap, or has debris in the detonator is strictly prohibited from use.
The vertical end of the fuse or detonating tube should be gently inserted into the detonator without rotation and friction. Metal shell detonators should be tightened with safety clamps, and paper shell detonators should be tied with tape or put on a metal hoop and tightened.
The processing of detonating charges should be carried out in a safe place near the blasting operation surface, and the processing quantity should not exceed the required amount for the blasting operation on duty. During processing, a wooden or bamboo awl should be used to poke a hole the size of a detonator in the center of the explosive roll. The hole should be deep enough to insert the detonator completely without exposing the explosive roll. After the detonator is inserted into the explosive roll, it should be tightened with a thin rope or the leg wire of the electric detonator.
• Electric detonation
In a separate room or outdoor safe place, only special blasting instruments are allowed to check the resistance value of the electric detonator used for each blasting one by one. The resistance value should comply with the provisions of the product certificate. The matters that should be paid attention to when checking the electric detonator are the same as those when processing the explosive package.
The electric detonators used in the same blasting network should be products of the same factory, the same batch, and the same model, and the resistance value difference of the Constantan bridge wire detonator should not exceed 0.3Q, and the silver bridge wire detonator should not exceed 0.5Q.
Only special blasting bridges are allowed to conduct the network and check the resistance.
Before the blasting main line is connected to the detonation power supply or detonator, the total resistance value of the entire line must be measured. The total resistance value should be consistent with the actual calculated value (allowable error 5%). If not, connection is prohibited.
When detonating with electricity in general blasting operations, the AC current flowing through each detonator should be no less than 2.5A, and the DC current should be no less than 2A.
When detonating with power supply or lighting power supply, the detonator switch must be placed in a specially locked detonator box. The key to the detonator box must be kept strictly.
An intermediate switch should be installed in the main line of the blasting network.
For electric detonation of underground metal mines, all power supplies on the working face must be removed before loading.
• Detonator detonation
Detonator detonation is prohibited in any of the following situations: blasting of working faces with gas and dust explosion hazards; deep hole blasting; working faces with large amounts of water.
Detonator detonation is not suitable for blasting of vertical shafts, inclined shafts with an inclination angle greater than 30. and skylight working faces. When detonating with detonators, resistance wire ignition or other forms of one-time ignition methods should be used.
When using a fuse to detonate, the following regulations must be observed: Use the one-time ignition method to ignite; Before ignition, the fuse must be cut off 5cm with a sharp knife, and it is strictly forbidden to cut the fuse while igniting; The number of fuses that each person ignites in the same work must not exceed 5; The fuse must be ignited with a fuse or a special igniter, and it is strictly forbidden to ignite with matches, cigarette butts and lights; It is strictly forbidden to step on and squeeze the ignited fuse; When igniting a single fuse, the length of the fuse should ensure that after the fuse is lit, the personnel can retreat to a safe place, but the shortest cannot be less than 1.2m; When igniting multiple fuses in succession, the timing fuse must be ignited first. After the timing fuse burns out, whether it is lit or not, the personnel must evacuate immediately; The length of the timing fuse must not exceed one-third of the length of the shortest fuse in the fuse that was ignited.
• Detonating Cord Detonation
Only a sharp knife is allowed to cut the detonating cord, but it is forbidden to cut the detonating cord connected to the detonator or inserted into the explosive.
The detonating cord detonation network should be connected by overlapping, sailor's knot and other connection methods. When overlapping, the overlapping length of two detonating cords shall not be less than 15cm, and the binding shall be firm. The angle between the branch line and the main line transmission direction shall not be greater than 90. .
Except for the sailor's knot when connecting, the detonating cord network is prohibited from knotting or looping. When staggered laying detonating cords, a pad with a thickness of not less than 10cm should be placed between the two detonating cords.
The detonator for detonating detonating cords should be tied 15cm away from the end of the detonating cord, and the concentrated hole of the detonator should face the direction of the detonation of the detonating cord.
•Detonating cord detonation
There shall be no dead knots in the detonating cord network, and the detonating cords installed in the hole shall not have joints. The detonating cords used for the same working surface must be products of the same factory and batch number.
There should be enough space between the detonating tubes outside the hole. When the detonating tube network is detonated with detonators, measures should be taken to prevent the concentrated hole of the detonator from cutting off the detonating tube and causing explosion refusal.
The detonating tube should be evenly laid around the detonator to prevent the air hole of the second delay detonator from burning the detonating tube.
It is forbidden to use detonating tubes for blasting in mines with the risk of mine dust or gas explosion.
(3) Safety management of underground blasting
When the tunnel is penetrated by blasting, when the two working faces are 15m apart, only one working face is allowed to advance forward, and guards should be sent at the safe places leading to the working faces on both sides. Detonation is allowed only after the personnel of both sides have evacuated to a safe place.
When two parallel tunnels with a spacing of less than 26m are excavated at the same time, when blasting is carried out on the working face of one tunnel, the personnel of the working face of the other tunnel must evacuate to a safe place.
When transporting explosive packages in the shaft, the explosive packages must be placed in special wooden boxes or bags. Bottom-unloading buckets shall not be used. It is forbidden to transport detonating charges and explosives at the same time.
When transporting blasting materials to the wellhead excavation working face, no one except the blaster shall remain in the wellbore.
When the wellbore is excavated, all joints of the electric blasting network must be tightly wrapped with insulating tape and raised above the water surface.
Before detonation, all personnel must evacuate the danger zone. Warning signs must be set up at the entrance to the blasting site. Detonation is allowed only after it is confirmed that there is no one in the blasting danger zone.
4. Storage and transportation safety of blasting materials
(1) Storage of blasting materials
• Permanent ground warehouse
Permanent ground blasting material warehouse should be a bungalow with a brick-concrete structure. The walls should be strong, dense, heat-insulated and corrosion-resistant. The roof should be made of reinforced concrete with an insulation layer. If a wooden roof is used, it must be fire-proofed. Warehouses for storing pyrotechnics and nitroglycerin explosives must use light roofs. The floor should be flat, solid, crack-free, moisture-proof, and corrosion-resistant, and no ironware should be exposed on the surface. The detonator warehouse uses wooden floors with soft pads.
Storage and management of nitroglycerin explosives, detonators, and follow-up explosives must be placed on shelves. Boxes (bags) are prohibited from being stacked. The distance between the box and the upper layer of the shelf shall not be less than 4cm. The width of the shelf shall not exceed the width of two packaging boxes (bags). The distance between the shelves shall not be less than 1.3m, and the distance between the shelf and the wall shall not be less than 20cm. Other blasting equipment should be stacked on wooden pallets, with a distance of not less than 1.3m between each pile, not less than 20cm from the wall, and a height of not more than 1.6m. Tools and sundries not related to management work shall not be stored in the warehouse; the warehouse must be clean, moisture-proof, well ventilated, and rodent-free.
The warning warehouse area must be guarded day and night, patrols must be strengthened, and irrelevant personnel are strictly prohibited from entering the warehouse area. The alarm device and fire protection, communication and lightning protection devices should be checked once a quarter. If the explosive materials are lost or stolen, they must be reported to the local public security organs in time.
• Permanent tunnel-type carcass warehouse
The height of the warehouse of the permanent tunnel-type carcass warehouse must be greater than the height of the connecting tunnel. The slope of the connecting tunnel bottom plate is 5%o from the inside to the outside, and there is a covered drainage ditch. There must be ventilation tunnels or ventilation shafts for ventilation. The entrances and ventilation equipment of the ventilation tunnels and ventilation shafts must be fenced. The support is generally sprayed concrete support plus off-wall arches. If wooden structure support is used, fireproof paint should be applied.
The storage and warning of explosive materials in permanent tunnel-type cave warehouses are the same as those on the surface of explosive warehouses.
• Underground sub-warehouses and distribution stations
There are no special requirements for the structure of underground sub-warehouses and distribution stations. It is only required that the carcass room and wall groove for storing nitroglycerin explosives and detonators should be equipped with metal mesh doors, and fireproof iron doors should be installed at the entrances and exits.
In a mine with multiple middle sections, when the distance between the blasting equipment sub-warehouse and the working face exceeds 2.5km or there is no sub-warehouse underground, it is allowed to set up a distribution station in each middle section. The underground blasting equipment distribution station must meet the following requirements: There should be a dedicated ventilation tunnel. The distance from the pedestrian tunnel should be no less than 25m, and it should be connected to the pedestrian tunnel by at least one right-angle turn. Storage volume: explosives should not exceed 500kg, and detonators should not exceed one box. Explosives and detonators must be stored separately, separated by brick walls or concrete walls, and the thickness of the partition wall should not be less than 25cmo
•Surface temporary warehouse
The surface temporary warehouse must have an independent distribution room with an area of no less than 9 square meters, and an independent detonator warehouse should be set up, preferably with a wall or iron barbed wire no less than 2m high. There must be enough fire-fighting equipment in the warehouse. The temporary warehouse (preferably a bungalow) must have a flat and seamless floor. If the walls, floors, roofs and doors are wooden structures, they should be painted with fireproof paint. The windows must have a layer of plate windows and doors covered with iron sheets.
• Special compartments of cars or carriages for storing explosives
In field mobile blasting operations that do not exceed 6 months, special compartments of cars or carriages are allowed to store explosives, but the following regulations must be observed:
① It is prohibited to make special compartments into trailers; special compartments must be wooden compartments covered with iron sheets, and the front and side walls of the compartments should have 30cmx30cm iron grille ventilation holes, and the rear wall should have doors, which are wooden doors covered with iron (or aluminum) sheets. The door should be locked, and the entire compartment surface should be painted with fireproof paint and marked with danger.
② The amount of explosives stored shall not exceed two-thirds of the rated load of the vehicle.
③ A wooden box for detonators is fixed in the front right corner of the carriage, lined with soft padding and locked separately. When loading explosives and detonating equipment on the same car, the number of detonators and corresponding fuses and detonating cords shall not exceed 2,000.
