This standard specifies the safety level of permissible explosives, coal dust and combustible gas in coal mines, test materials, instruments, devices, test conditions, test steps, test result presentation and judgment, etc. This standard is applicable to the test of permissible explosives, coal dust and combustible gas safety in coal mines. MT/T 934-2005 Test method and judgment of permissible explosives, coal dust and combustible gas safety in coal mines MT/T934-2005 Standard download decompression password: www.bzxz.net

ICS 71.100.30
Registration No.: 15494--2005
Coal Industry Standard of the People's Republic of China
MT/T934—2005
Test method and adjudgement of safty of permissible expiosiveingrimeand inflammable gas
2005-03-19 Issued
National Development and Reform Commission
2005-06-01 Implementation
Normative reference documents
Terms and symbols
Technical requirements
Test methods
Result determination
MT/T934—2005
MT/T934—2005
The full text of this standard is a mandatory standard. Foreword
This standard is proposed by the Science and Technology Development Department of the China Coal Industry Association. This standard is under the jurisdiction of the Coal Industry Coal Mine Safety Standardization Technical Committee. This standard is drafted by the National Coal Mine Explosion-proof Safety Product Quality Supervision and Inspection Center and the Coal Industry Zhunbei Explosive Equipment Product Quality Supervision and Inspection Center.
The main drafters of this standard are: Zhang Chunyu, Xia Bin, Duan Zan, Dong Chunhai, Song Jialiang, Liu Yongming, and Zheng Feng. 1 Scope
MT/T934—2005
Test methods and judgments for the safety of coal dust-combustible gas, which is permitted explosive in coal mines. This standard specifies the safety level, test materials, instruments, devices, test conditions, test steps, expression and judgment of test results of coal dust-combustible gas, which is permitted explosive in coal mines. This standard applies to the test of the safety of coal dust-combustible gas, which is permitted explosive in coal mines. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties who reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated references, the latest versions shall apply to this standard. GB8031 Industrial electric detonator
GB18095—2000 Emulsion explosive
3 Terms and symbols
3.1 Terms
Permissible explosive in coal mines Explosives permitted to be used in mines with danger of explosion of combustible gas or coal dust. 3.1.2
Inflammable gas; Combustible gas Gas that can burn or explode after mixing with air. 3.1.3
Grime
Flying fine coal particles.
Safety
Safety of explosives used in coal mines with danger of explosion of combustible gas or coal dust. 3.1.5
Half ignition disc samplemean
The mass of explosives with a probability of ignition of 50% under specified conditions. 3.1.6
interval
The absolute value of the difference between two adjacent test levels. 3.1.7
Small sample up-and-down methodSmall sample up-and-down methodTest method for finding the mean value of a single-factor random variable with a sample size of no more than 6. 3.2 Symbols
a) Mso: half ignition quantity, g;
b) m5o: half ignition quantity standard value, g
MT/T 934—2005
c) n: sample size;
d: interval, g+
e) i: test level sequence number, integer;
M. : initial test level, g;
g) M the i-th test level, g;
h) K: the number of tests under the test level. 4 Technical requirements
The safety level of permissible explosives for coal mines is divided into level 1, level 2 and level 3. The standard value of half ignition volume (m5c) of each level is shown in Table 1. Table 1 Safety level of permissible explosives for coal mines Level
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Test method
Scope of application
5 Test method
5.1 Principle
≥150
≥250
Low methane mine Coal seam mining High methane mine; Low methane mine high methane mining working face; Coal low methane mine rock excavation
Working face
Working face
Oil symbiotic mine; Coal and coal seam gas outburst mine Under specified conditions, the small sample lifting method is used to suspend the tested explosive in the center of the tunnel explosion chamber for explosion. According to the ignition results of the coal dust-combustible gas mixture in the test tunnel, the half ignition amount is calculated to determine the coal dust-combustible gas safety of the explosive. 5.2 Experimental design
a) Sample size: n=6;
Ladder spacing: d=25g;
Initial test water: Mg=m5o+d;
Lifting and lowering rules: The test is ignited at the M level, and the next test level is reduced by one ladder spacing d; otherwise, one ladder spacing d is increased. It is not allowed to skip the ladder spacing or keep the test level unchanged. 5.3 Materials
5.3.1 Test gas: The volume fraction of methane should not be less than 90%, and the sum of the volume fractions of other combustible gases should not be greater than 1%. 5.3.2 Coal dust: volatile matter should not be less than 35%, ash content should not be greater than 12%, moisture content should not be greater than 3%, particle size is taken from the standard sieve system composed of 100μm, 74m and 50μm, the part on the 74μm and 50μm two-layer sieve, and the passing rate of 74um standard sieve is not less than 75%. 5.3.3 Detonator: GB8031, instantaneous electric detonator allowed for coal mines. 5.3.4 Explosives: GB18095, emulsion explosives allowed for third-level coal mines, 5.4 Instruments and devices
Instruments:
Methane detector: the graduation value should not be greater than 0.02%; b)
Thermometer: the graduation value should not be greater than 1℃:
Hygrometer: the graduation value should not be greater than 5%;
Balance: the sensitivity should not be greater than 0.5g.
5.4.2 Device:
Coal dust-combustible gas safety test device. It is mainly composed of test tunnel, gas mixing pipeline, mixing fan, smoke exhaust fan and control system, as shown in Figure 1.
The test tunnel is a steel cylinder, divided into two parts: explosion chamber and extension chamber, placed horizontally, with an inner diameter of 1.8m and a length of 5m
MT/T934-2005
or an inner diameter of 1.5m and a length of 6m in the explosion chamber. There is a circular opening in the center of the closed end of the explosion chamber, and a closing device is provided at the open end. The extension chamber is about 15m long and is connected to the open end of the explosion chamber. The gas mixing pipeline consists of an air intake pipe, a return air pipe and a valve. The air intake pipe is introduced from the upper part of the closed end of the explosion chamber, and the return air pipe is introduced from the lower part of the open end of the explosion chamber. Valves should be installed on the air intake pipe and the return air pipe respectively. Mixing fans and smoke exhaust fans should be explosion-proof. Traffic jam, a steel body that can move forward and backward to block the smoke exhaust hole. d)
Test tunnel;
Extension chamber;
Closing device;
An explosion chamber:
Measuring hole;
An exhaust fan:
A traffic jam;
Mixing pipeline;
-Mixing fan;
Valve.
Tested explosive package
Coal dust package
Figure 1 Schematic diagram of coal dust-combustible gas safety test device 5.5 Test conditions
5.5.1 The sample is made of explosive original rolls, and the temperature of the explosive should be 5~35℃. 5.5.2 The volume fraction of methane in the coal dust-methane gas mixture in the explosion chamber should be 4.0% ± 0.3%, and the coal dust concentration should be 100g/m3 (equivalent to 1.0kg of coal dust).
5.5.3 The ambient temperature should be controlled at 5-35℃, and the relative humidity should not exceed 80%. 5.5.4 The flying coal dust uses 20g of the third-level coal mine permitted emulsion explosive. 5.6 Test steps
5.6.1 Weigh 1.0kg ± 1g of coal dust and 20g ± 0.5g of the third-level coal mine permitted emulsion explosive. Insert a detonator into the 20g ± 0.5g powder roll, and bury it in 1.0kg ± 1g of coal dust to make a coal dust bag. 5.6.2 Determine the mass of the sample according to 5.2. When weighing the sample, the sample mass includes the mass of the outer packaging. Insert the detonator into one end of the sample to make a test powder bag.
5.6.3 Suspend the coal dust bag in the lower middle of the tunnel, and suspend the test explosive in the center of the tunnel above the coal dust bag, with a distance of 0.5m between them, as shown in Figure 1.
5.6.4 Use kraft paper or plastic film to seal the open end of the explosion chamber. 5.6.5 Push the traffic jam to the closed end of the explosion chamber and press it tightly, so that the boss enters the closed end round mouth, and its end face is flush with the inner wall of the closed end. MT/T934--2005
5.6.6 Turn on the mixing fan, fill the explosion chamber with test gas, and measure the temperature, relative humidity and methane concentration of the mixed gas. 5.6.7 When the gas in the explosion chamber is mixed evenly and the methane content reaches the requirement, stop filling, close the mixing fan and related valves, and open the pressure relief valve at the same time.
5.6.8 Connect the detonation circuit, detonate the coal dust bag within 2 minutes after closing the mixing fan, and detonate the test explosive immediately after 0.5s. 5.6.9 Check whether the test explosive is fully exploded. If it is not exploded or half-exploded, this test is invalid and the horizontal test is repeated. 5.6.10 Observe whether the coal dust-mixed gas is detonated and record it. 5.6.11 Open the smoke exhaust fan and the mixed fan air inlet valve at the same time, open the mixed fan, and exhaust the blasting smoke in the tunnel. The exhaust time shall not be less than 3 minutes.
5.6.12 Reset each valve to the initial state of the test. 5.7 Result Expression
5.7.1 Test Record:
The test results shall be recorded in the record format of the example in Table 2. "Ignition" is recorded as "1", and "no ignition" is recorded as "0". Table 2 Example of small sample lifting method test record
Test results
Note: "1" in the table means that the first two tests have the same results. When calculating half of the ignition amount, the first test result is discarded. The "" of the 7th test level is virtual based on the result of the 6th test, that is, if the 6th test is "ignition", it will be reduced by one step, otherwise it will be increased by one step. 5.7.2
Data processing:
Take the 6 consecutive test results starting from the opposite test results in the test sequence, and virtualize the 7th test result. Calculate the half ignition amount according to the following formula, and round the final result to the single digit. M. = k;M,/7
6 Result determination
6.1 If Mso≥mso, the safety of the sample is determined to be qualified. 6.2 If mso-Ms>20g, the safety of the sample is determined to be unqualified. Otherwise, according to the 6th test result, continue to do 6 tests, and then virtualize the 13th test result to calculate the half ignition amount of the 13th test level. If Ms≥m50, the safety of the sample is determined to be qualified; otherwise, it is determined to be unqualified.
6.3 If the test level rises to mso+3d and there is still no ignition, stop the test, and use Ms≥ms as the test result to determine that the safety of the sample is qualified.
MT/T 934—2005
Coal
Industry Standard of the People's Republic of China
Test Method and Judgment of Safety of Permissible Explosives Coal Dust-Combustible Gas in Coal Mines
MT/T9342005
Published by China Coal Industry Press
(No. 35, Yaoyaoju, Chaoyang District, Beijing 100029)Website: www.cciph.com.cn
Printed by Beijing Geological Printing Factory
New Published by Beijing Publishing House of Huashu Bookstore
Format 880mm×1230mm1/16
Word count 7,000 words
First edition in May 2005
Printing sheet 5/8
Print run 1-300
First printing in May 2005
5020·21
All rights reserved. Violators will be prosecuted
If there are any quality problems such as missing pages, reversed pages, or pages falling off, this publisher will be responsible for replacing them
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