MT 519-1995 Technical conditions for permissible detonating cords in coal mines MT519-1995 standard download decompression password: www.bzxz.net

Coal Industry Standard of the People's Republic of China
Technical Conditions for Permissible Detonating Cords in Coal Mines
1 Subject Content and Scope of Application
MT 519—1995
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of permissible detonating cords in coal mines. This standard applies to permissible detonating cords (hereinafter referred to as detonating cords) in coal or rock bodies with explosive gas (and coal dust) hazard underground for blasting operations in coal mines. The detonating cords must be tightly sealed in the blasthole. Reference standards
Dangerous goods packaging mark
GB1901
GB2828Batch inspection counting sampling procedure and sampling table (applicable to continuous batch inspection)GB6543Corrugated paper box
GB8031Industrial electric detonator
GB9786Ordinary detonating cord
GB10111Random sampling method using random number YinziMT61Safety level of biogas for permissible explosives in coal mines and its inspection methodWI85Technical conditions for pressing and acceptance of explosive column, detonator charge and explosive block3Technical requirements
3.1The product shall comply with the provisions of this standard and shall be manufactured according to the technical documents approved by the prescribed procedures. 3.2Appearance:
The surface of the detonating cord shall be yellow, and the coating shall be uniform, without bubbles, sand holes, cracks and serious fractures. 3.3 Size:
The outer diameter of the detonating cord should not be greater than 7.0mm, the length of the roll should not be less than 50m, and the shortest cord section should not be less than 10m. 3.4. Performance:
3.4.1 Detonation velocity: should not be less than 6000m/s. 3.4.2 Detonation capability: after the detonation test, it should be able to completely detonate the 200g pressed TNT block that meets the requirements of WJ85. 3.4.3 Explosion transmission performance: after the explosion transmission test, it should detonate completely. 3.4.4 Water resistance: after the water immersion test, it should detonate completely. 3.4.5 Heat resistance: after the high temperature test, it should detonate completely. 3.4.6 Cold resistance: after the low temperature test, it should detonate completely. 3.4.7 Flame sensitivity: after the ignition test, it should not be detonated. 3.4.8 Bending resistance: after the bending test, there should be no surface cracks and it should detonate completely. 3.4.9 Tensile performance: It should not break after static tensile test and should explode completely. 3.4.10 Safety: After safety test, the frequency of detonation of combustible gas by detonating cord should be 0/5 or 1/15. 3.4.11 Guarantee period: 2 days.
Approved by the Ministry of Coal Industry of the People's Republic of China on January 15, 1996 and implemented on May 1, 1996
4 Test method
4.1 Appearance inspection
MT 519—1995
Unfold the sample and check its appearance by visual method. 4.2 Dimension measurement
Measure the diameter of each sample at five different locations with a micrometer or vernier caliper, and take the arithmetic mean of the measurement results in perpendicular directions at each location, accurate to 0.1mm. Use a tape measure (measuring range 0~50m; accuracy 5mm) or a special measuring tool to measure the unfolded length of the sample, accurate to 0.1m.
4.3 Detonation velocity determination
Take a 1.5m long detonating cord, use a detonation velocity meter with an accuracy of 1μs, and a probe made of enameled wire with a length of 150~~200mm and a diameter of 0.1~0.15mm, assemble according to Figure 1 to measure the detonation velocity. The detonation velocity is calculated as follows: ×103
Where: -——detonation velocity of the tested detonating cord, m/s; -distance between probes, mm;
time displayed by the detonation velocity meter, us.
Figure 1 Schematic diagram of the detonation velocity measurement of detonating cord
1-detonating cord, 2-probe, 3-target line, 4-detonator: 5-conducting wire, 6-initiator; 7-detonation velocity meter
4.4 Detonation test
Take a 1.5m long detonating cord and tie it to a 200g pressed TNT block according to Figure 2. Insert one end of the detonating cord into the detonator hole of the block. The detonating cord should be in contact with the block. Use No. 8 detonator (GB8031) to detonate and observe whether the block is completely detonated. 660
4.5 Explosion transmission test
MT 519—1995
Figure 2 Schematic diagram of the detonation ability test of detonating cord
1-wire or thin rope; 2-conducting wire; 3-initiator, 4-detonator, 5-wire or thin rope, 6-detonating cord; 7-200g pressed TNT block Take a 20m long detonating cord and detonate it with a No. 8 detonator (GB8031) to observe whether the detonation is complete. 4.6 Water immersion test
Take a 20m long detonating cord, seal the cord head and put it into a sealed container with a water temperature of 1025℃, pressurize it to 50±5kPa, and continue for 5h. Take out the detonating cord after immersion in water, wipe off the water marks on the surface, cut off the cord head and test it according to 4.5 to observe whether the detonation is complete. 4.7 High temperature test
Take 20m long detonating cord, roll it into a coil with a diameter of not less than 250mm, put it in a constant temperature box, keep it at 50±2℃ for 6 hours, then take it out, and test it according to 4.5 to observe whether it is completely detonated. 4.8 Low temperature test
Take 20m long detonating cord, roll it into a coil with a diameter of not less than 250mm, put it in a low temperature box, keep it at -40±2℃ for 2 hours, then take it out, and test it according to 4.5 to observe whether it is completely detonated. 4.9 Ignition test
Take 5 pieces of 50mm long detonating cord, place one piece at a time in the explosion-proof device, spray the end core with the flame of the fuse within 50mm of its end face, and observe whether it detonates.
4.10 Bending test
Take 2 detonating cords of 20m in length, put one in a constant temperature box at 50±2℃ for 6h; put the other in a low temperature box at -40±2℃ for 2h. Immediately after taking out, bend each detonating cord 4 times at 90° on a 5mm diameter shaft at 3 different locations, and observe whether the surface layer at the bend is broken. Then observe whether the detonation is complete according to the test in 4.5. 4.11 Static tensile test
Take a detonating cord of not less than 500mm in length, clamp it on a material tensile testing machine with protective devices or a special tensile testing device at room temperature, with a clamping distance of not less than 200mm, and evenly increase the tensile force to 500N. After 1min, observe whether it breaks. Remove the sample, detonate it with No. 8 detonator (GB8031), and observe whether the detonation is complete. 4.12 Safety test
4.12.1 Instruments and equipment
a. Test tunnel: a steel cylinder with a diameter of 1.8m and a length of 20m, one end of which is closed with a steel plate with a circular hole in the center of the steel plate, and a closed ring from this end to 5m. The space from the closed ring to the closed end is the explosion chamber. There are pipelines on both sides of the explosion chamber for mixing combustible gases. Observation holes and measuring holes (for measuring methane concentration, temperature, humidity and other parameters) are opened as needed. 661
MT 519-1995
Firing white gun: a steel cylinder with a diameter of 560mm and a length of 1200mm, with a gun eye with a diameter of 55mm and a length of 900mm in the center of one end. The white gun is installed on a gun carriage.
Fan: Mixing fan is explosion-proof, with air volume of 1330～2450m/h and air pressure of 2.9×10-2hPa; exhaust fan C
is explosion-proof, with air volume of 73600m/h and air pressure of not less than 4.9×10~2hPa. d.
Methane detector: minimum scale value 0.1%. Thermometer: minimum scale value 0.5℃.
Steel ruler: minimum scale value 1mm.
Test conditions
Underground combustible gas: Natural gas extracted from underground coal mines, with methane as the main component, and the content of other combustible gases should not be greater than 0.5%. Methane concentration in mixed gas in explosion chamber: (9.0±0.3)% (V/V). Explosion chamber temperature: 10～30℃.
4.12.3 Test steps
4. 12. 3. 2
Before using the methane detector, check its air tightness and calibrate the zero point. Use a steel ruler to accurately measure the 10m long detonating cord and suspend it in the explosion chamber as shown in Figure 3. Figure 3 Schematic diagram of the suspension of the detonating cord in the tunnel explosion chamber 1-detonator, 2 tunnel 3-detonating cord
4.12.3.3 The closed ring of the explosion chamber is sealed with paper or plastic film. 4.12.3.4 Connect the detonator to the detonating end of the detonating cord. 4.12.3.5 Push the white gun to the closed end of the tunnel, align the blasthole with the center hole, and keep the two ends in close contact. 4.12.3.6 If the temperature in the explosion chamber does not meet the requirements, it should be adjusted to reach the specified temperature. 4.12.3.7 Open the valve of the mixing pipeline and start the mixing fan, fill the explosion chamber with combustible gas, measure the methane concentration, and make it reach the specified concentration. When the mixture is evenly mixed, stop filling and mixing. Detonate within 3 minutes after stopping. 4.12.3.8 Close the valve of the mixing pipeline and open the explosion relief valve. 4.12.3.9 Record the temperature of the tunnel explosion chamber. 4.12.3.10 Detonate after sending a signal and observe whether the combustible gas is detonated. 4.12.3.11 Turn on the exhaust fan to remove the explosion smoke. 4.12.3.12
Record the test results.
MT 519—1995
Figure 4 Schematic diagram of the detonating cord combustible gas safety test device 1—Test tunnel; 2—Enclosed loop; 3—Observation hole; 4—Air conditioning room; 5—Explosion room; 6—Launch white cannon; 7—Exhaust fan; 8—Measurement hole; 9—Pipeline valve; 10—Mixing fan, 11—Combustible gas cylinder 5 Inspection rules
5.1 Factory inspection
5.1.1 Products shall be inspected by the quality inspection department of the manufacturer and shall not be shipped out until they pass the inspection and are issued a certificate of conformity. 5.1.2 Factory inspection items
The factory inspection items include the appearance, size, explosion transmission performance and detonation velocity of the detonating cord. 5.1.3 Batch grouping and judgment rules
5.1.3.1 Generally, the inspection batch is composed of 1201~3200mm, which can also be agreed upon by the supply and demand parties according to the requirements of the user. 5.1.3.2 Factory inspection shall be carried out in accordance with the provisions of GB2828. 5.1.3.2.1 Appearance inspection
Inspection level\S-3", one-time sampling, AQL value of minor defects is 4.0%, AQL value of major defects is 1.0%, and the inspection unit is meter. Minor defects: uneven surface.
Major defects: bubbles, sand holes, cracks, and severe fractures.5.1.3.2.2 Dimension inspectionbZxz.net
Inspection level "S-2", one-time sampling, AQL value of minor defects is 4.0%; the inspection unit is rope coil. Minor defects: diameter greater than 7.0mm, rope coil length less than 50m, and the shortest rope section less than 10m.5.1.3.2.3 Detonation velocity inspection
Inspection level "S-2", two-time sampling, AQL value of major defects is 6.5%, and the inspection unit is gun. Major defects: detonation velocity less than 6000m /s.
5.1.3.2.4 Explosion transmission performance test
Inspection level "S-1", secondary sampling, AQL value of severe defects 10%, with gun as the inspection unit. Severe defect: incomplete detonation.
5.2 Type inspection
5.2.1 Type inspection shall be the responsibility of the product quality supervision and inspection agency authorized by the Ministry of Coal Industry. 5.2.2 Type inspection shall be carried out in any of the following circumstances: a.
Trial production and identification of new products or old products transferred to the factory for production; 663
MT519—1995
b. After formal production, if there are major changes in structure, materials, and processes that may affect product performance; c. During normal production, regular inspections shall be carried out; d. Continuous shutdown of product production lines More than half a year, when production is resumed; e. When there is a significant difference between the factory inspection results and the last type inspection; f. When the national quality supervision agency proposes a requirement for type inspection. 5.2.3 Type inspection items
Type inspection items include the size, detonation velocity, initiation ability, explosion transmission performance, water resistance, heat resistance, cold resistance, flame sensitivity, bending resistance, tensile strength and safety of the detonating cord. 5.2.4 Sampling and judgment principles
Specimens are selected from qualified products produced in the same production cycle, and the specimens are randomly selected according to the method specified in GB/T10111. The sample size shall not be less than 300m. When all the inspected items are qualified, the product is judged to be qualified. In the inspection of the specified items, if the safety or two or more other test results are unqualified, it is judged. The product is deemed unqualified. When one or two test results other than safety are unqualified, the unqualified items shall be doubled for testing. When the test results meet the requirements, the product is still deemed qualified, otherwise the product is deemed unqualified. 6 Packaging, marking, transportation and storage
6.1 The cable rolls are first wrapped with wax paper or packed into polyethylene plastic bags and sealed, and then packed into corrugated paper boxes (GB6543), wooden boxes or fiberboard boxes. Each box has a capacity of 500m, and is accompanied by product instructions and certificates. 6.2 The outer wall of the packaging box should have the following markings:
Product name;
Batch;
Quantity;
Quality;
Volume;
Production date;
Manufacturer name:
h. "Fireproof", "Moisture-proof", "Handle with care", "Do not put together with detonators" and other words or signs; i. Explosives markings in accordance with GB190. 6.3 The transportation of detonating cords shall comply with the relevant national regulations on the transportation of dangerous goods. 6.4 Detonating cords shall be stored in a well-ventilated warehouse with a temperature not exceeding 40°C. 66.
Additional Notes:
MT519—1995
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Blasting Technology and Explosives Technical Committee of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was jointly drafted by the Fushun Branch of the China Coal Research Institute and the 12th Factory of the Fuxin Mining Bureau. The main drafters of this standard are Dong Chunhai, Yang Zuyi, Qin Ge, Liu Yongming, Zhao Weicheng, Yang Shuqin, and Chen Wensheng. This standard was entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 6652 The outer wall of the packaging box should have the following signs:
Product name;
Batch;
Quantity;
Quality;
Volume;
Production date;
Manufacturer name:
h. "Fireproof", "Moisture-proof", "Handle with care", "Do not put together with detonators" and other words or signs; i. Explosives signs in accordance with GB190. 6.3 The transportation of detonating cords shall comply with the relevant national regulations on the transportation of dangerous goods. 6.4 Detonating cords should be stored in a well-ventilated warehouse with a temperature not exceeding 40°C. 66.
Additional instructions:
MT519—1995
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Blasting Technology and Explosives Technical Committee of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was jointly drafted by the Fushun Branch of the China Coal Research Institute and the 12th Factory of the Fuxin Mining Bureau. The main drafters of this standard are Dong Chunhai, Yang Zuyi, Qin Ge, Liu Yongming, Zhao Weicheng, Yang Shuqin, and Chen Wensheng. This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation.2 The outer wall of the packaging box should have the following signs:
Product name;
Batch;
Quantity;
Quality;
Volume;
Production date;
Manufacturer name:
h. "Fireproof", "Moisture-proof", "Handle with care", "Do not put together with detonators" and other words or signs; i. Explosives signs in accordance with GB190. 6.3 The transportation of detonating cords shall comply with the relevant national regulations on the transportation of dangerous goods. 6.4 Detonating cords should be stored in a well-ventilated warehouse with a temperature not exceeding 40°C. 66.
Additional instructions:
MT519—1995
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Blasting Technology and Explosives Technical Committee of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was jointly drafted by the Fushun Branch of the China Coal Research Institute and the 12th Factory of the Fuxin Mining Bureau. The main drafters of this standard are Dong Chunhai, Yang Zuyi, Qin Ge, Liu Yongming, Zhao Weicheng, Yang Shuqin, and Chen Wensheng. This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation.
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