Decree No. 293 / 2003 Coll.
Ordinance on the Closer Conditions and Characteristics of Explosives intended for use in or in Hazard Conditions and on checking the performance of such Explosives
Valid
Order
Effective from 01.10.2003
Zobrazeno prvních 200 z celkem 367 ustanovení tohoto předpisu.
Zobrazit celý předpis →
Pro stažení celého znění použijte tlačítko Stáhnout výše.
293
DECLARATION
of 28 August 2003
on the closer conditions and characteristics of explosives intended for use in or in a risk environment and on checking the characteristics of such explosives
Pursuant to § 28a (1) of Act No. 61 / 1988 Coll., on Mining Activities, Explosives and State Mining Administration, as amended by Act No. 315 / 2001 Coll.:
Subject matter
The Decree sets out detailed conditions for the use of explosives in risk conditions or in a risk environment, their characteristics and checking of the properties of such explosives.
Basic concepts
For the purposes of this decree:
(a) a strictly safe explosive - explosives, detonators and detonators which, by examination of the characteristics, fulfil the conditions set out in the Annex to this Regulation;
(b) risk conditions - temperature conditions where the temperature at the site of use of explosives is higher or comparable to the temperature of the explosion of the most sensitive explosives used in these conditions, 1)
(c) hazardous environment - explosive gas or dust environment, or mixtures of such substances (e.g. coal mines with a risk of explosion of coal dust2) or flowing mines 3) with the ordered use of strictly safe explosives. 4)]
Further conditions for the use of explosives under risk conditions or in a risk environment, their characteristics and checking of these properties are set out in the Annex to this Decree.
Permit to use a mine-safe explosive
(1) Authorisations for the first use of a single type of mine-safe explosive in a hazardous environment or in hazardous conditions (5) may be issued after the manufacturer or importer (the applicant) has submitted to the Czech Mining Authority:
(a) conformity assessment with the essential requirements for safety 6) by an authorised person providing an activity to the extent specified in the decision on the authorisation for the assessment of conformity of explosives under a specific legislation, 7)
(b) a technical dossier containing instructions for the use of a strictly safe explosive, the essential technical parameters identifying a rigorously safe explosive and its qualitative characteristics and findings developed by an authorized person, (7) that the explosives which are strictly safe comply with the requirements set out in the Annex to this Decree;
(c) the nature of the risk environment and, where appropriate, the risk conditions under which the explosive is to be used in a strictly safe manner.
(2) The Czech Mining Authority shall assess the documentation referred to in paragraph 1 and, in case of doubt, determine the scope of the additional checking of the characteristics by type of risk environment or, where appropriate, the risk conditions in which the explosive is to be used in a strictly safe manner. This examination of the requirements for the explosives which are strictly safe as set out in the Annex to this Decree is carried out by an authorised person under a special law. 7)
(3) The applicant shall submit to the Czech Mining Authority a document (finding) on the conduct and results of any checks, indicating whether the type of mine-safe explosive complies with the requirements set out in the Annex to this Decree.
(4) The specific parameters of strictly safe explosives intended for use in risk conditions and in a risk environment shall also be included in the instructions for use. These parameters must be fulfilled throughout the period of use.
Repeal
It shall be repealed:
1. Decree No. 246 / 1996 Coll., laying down more detailed conditions for the authorisation and checking of explosives, explosive articles and devices for circulation.
2. Decree No. 60 / 2002 Coll., amending the Order of the Czech Mining Office No. 246 / 1996 Coll., laying down more detailed conditions for the authorisation and checking of explosives, explosive articles and devices for circulation.
3. The proceeds of ČBÚ No 14 / 1969 of 20.1.1969 No 112 / 14 / 69 authorising the use of laminate charging bars TOKOZ (reg. in the amount of 25 / 1969 Coll.).
4. The income of ČBÚ No 20 / 1969 of 8.4.1969 No. 1313 / 20 / 69 authorising the use of mining ohmeter type KN-66 (reg. in amount 25 / 1969 Coll.).
5. The yield of ČBÚ No 40 / 1969 of 16.6.1969, no 2800 / 40 / 69, authorising the use of the ohmeter type MX-10 (reg. 7 / 1970 Coll.).
6. The yield of ČBÚ No 2 / 1970 of 26.1.1970 no. 5087 / 69 / 2 / 70 approving the type store of explosives M 200 (reg. 7 / 1970 Coll.).
7. ČBÚ Decree No. 13 / 1970 of 13.7.1970 No. 3777 / 5 / 70, authorising the use of pneumatic charging equipment marked BUNZA 1 C (reg. 7 / 1971 Coll.) for shredding operations in ČSR.
8. ČBÚ Decree No. 9 / 1971 of 10.5.1971 No. 2384 / 9 / 71 authorising the use of BRK-7 safety detonator pliers (reg. 27 / 1971 Coll.).
9. The proceeds of ČBÚ No 14 / 1976, No 26 / 1976 Ú. v. ČSR of 19.7.1976 č. 4388 / 15 / 76 which are authorised to be used in the shredding works of mine rock explosive DANUBAL 1 (reg in the amount of 25 / 1976 Coll., publ. in the amount of 7 / 1976 Ú. v. ČSR).
10. The proceeds of ČBÚ No 17 / 1979, No 1 / 1980 Ú. v. ČSR of 27.12.1979 č. 1565 / 17 / 79 concerning the authorisation to use the igniter ZRK-1 (reg. in amount 13 / 1980 Coll., publ. in amount 1 / 1980 Ú. v. ČSR).
11. The proceeds of ČBÚ No 22 / 1980, No 7 / 1981 Ú. v. ČSR of 26.11.1980, No. 811 / 22 / 1980 concerning the authorisation to use a pyrolighter (reg. in the amount of 13 / 1981 Coll., publ. in the amount of 2 / 1981 Ú. v. ČSR).
12. The proceeds of ČBÚ No 19 / 1980, No 9 / 1981 Ú. v. ČSR of 28.11.1980 no. 4448 / 19 / 1980 concerning the authorisation to use electric flash detonators SO- anti (reg. in amount 13 / 1981 Coll., publ. in amount 2 / 1981 Ú. v. ČSR).
13. The proceeds of ČBÚ No 15 / 1982, No 7 / 1982 Ú. v. ČSR of 1.7.1982 no. 540 / 15 / 1982 concerning the authorisation to use the type warehouse of explosives M 100 (reg. in the amount of 21 / 1982 Coll., publ. in the amount of 2 / 1982 Ú. v. ČSR).
Efficacy
This decree shall take effect on 1 October 2003, with the exception of the provisions of Sections 5 (1) and 5 (2), which shall take effect on the date of entry into force of the Treaty of Accession of the Czech Republic to the European Union.
Chairman:
Prof. JUDr. Makarius, CSc.
Annex to Decree No 293 / 2003 Coll.
Essential requirements for the characteristics of, and checks on, hard-to-safety explosives intended for use in risk conditions and risk environments
Strictly safe explosives
I. Strictly safe explosives are divided into:
1. anti-dust which comply with explosion tests and their limit load shall not cause a mixture of coal dust to ignite with air of 300 g.m-3;
2. antigas, the limit charge of which shall not cause the explosive mixture of methane to ignite with air at a concentration of 8,5 to 9,5% vol. and coal dust with air at a concentration of 300 g.m-3 and shall be divided by the degree of safety into three category8).
(a) Category I - anti-gas explosives which comply with the explosion tests in the drill shot in the explosive mixtures of methane with air and coal dust with air;
(b) Category II anti-gas explosives which comply with the tests of explosion on the edge of the reflector with a reflective wall in explosive mixtures of methane with air and coal dust with air (the walls of the gillings of the canopy are clamped with a reflective wall of 45 °); Furthermore, the explosive shall not show deflagration at 11 consecutive attempts, with an escape nozzle of 3,5 mm in diameter, or the critical mass of the M50 dust igniter for a 50% probability of inducing detonation of the explosive shall be greater than 18,0 g;
(c) Category III - anti-gas explosives which meet the tests of explosion on the edge of the reflector with a reflector wall in explosive mixtures of methane with air and coal dust with air (the walls of the gillers clasp with the reflective wall angles 0 ° and 90 °); Furthermore, the explosive shall not show deflagration at 11 consecutive attempts, with an escape nozzle 2 mm in diameter, or the critical mass of the M50 dust igniter for a 50% probability of inducing detonation of the explosive shall be greater than 21,0 g.
II. Review and classification of thoroughly safe explosives in explosive mixtures
1. The test chamber (Figure 1 to 4) is a steel cylinder with a diameter of 1 700 to 2 000 mm and a length of at least 5 000 mm. On one side it is firmly closed with a flat steel wall (face of the chamber) with a closing hole of between 300 mm and 400 mm in diameter and open to the other (for tests in a methanairic mixture, the aperture is closed). The center of the opening is in the axis of the chamber.
The chamber shall be equipped with a device for filling and mixing the methane / air mixture, for efficient ventilation after individual tests, for sampling of the explosive mixture from the chamber, for hanging bags with coal dust and for recording the explosion of the explosive mixture (special devices may be used to register the explosion of the explosive mixture or to hang an electric wire with PVC insulation in the chamber) and for measuring the temperature and relative humidity of the air in the chamber.
2. The drill bar is a cylinder of steel 12.040.1 or a glass laminate in which the core of the steel cathode is stored 16.540.7, in whose axis the drill is at least 42 mm in diameter. The ratio of the bore diameter to the explosive charges shall not exceed 1,5. The length of the drill is determined by the length of the test charge so that there is a free unloaded space of at least 100 mm between the mouth of the drill and the face of the first muzzle marker.
Dimensions in mm
1 - chamber test, 2 - drill, 3 - chassis, 4 - screen, 5 - chamber face
Fig. 1. Schematic of the test chamber and location of the drill hole during the testing of Category I dust and gas explosives
Dimensions in mm
1 - chamber experience, 2 - closing hatch, 3 - chassis, 4 - edge trigger, 5 - reflective wall, 6 - screen
Fig. 2. Diagram of the test chamber and location of the edge hole during the testing of gas explosives II. and III. category
3. The edge trigger is a steel cylinder of 12.060.4 with a diameter of 230 mm and a length of between 1000 and 2,000 mm, equipped with a rectangular selection of at least 90 mm across the length of the wall. The length of the hole shall be greater than the length of the test charge.
4. The reflecting wall is a steel plate with dimensions of at least 2,000 x 1,000 x 20 mm.
5. Landing gear for the position of a corkscrew or edge hole with a reflective wall in the position according to Figure 1 to 4.
Dimensions in mm
Fig. 3. Diagram of the location of the test equipment in Category II explosives tests
Fig. 4. Schematic of the location of the test equipment in Category III explosives tests
Dimensions in mm
1 - test chamber, 2 - reflective wall, 3 - test load, 4 - edge pointer, 5 - chassis
6. Gas for the preparation of a metallised mixture contains in% volume:
| metan | - nejméně 85 |
| homology metanu (jiné uhlovodíky) | - nejvíce 2 |
| nenasycené uhlovodíky a vodík | - nejvíce 0,2 |
| vzduch (dusík, kyslík a CO2) | - zbytek do 100 |
| oxid uhličitý | - nejvíce 2. |
7. Coal dust of physicochemical composition:
| prchavá hořlavina | - nejméně 28 % |
| popel (A) | - nejvýše 7 % |
| voda (W) | - nejvýše 2,5 % |
with a granulometric composition of:
• Rest on nets with mesh diameter 0,5 mm - maximum 1%
• the rest on nets with mesh diameter 0,071 mm - not more than 25%.
8. Cloth for closing the chamber space with a metallised mixture is made of paper, polyethylene foil etc.
9. A mine interfermeter or other device to measure the concentration of methane to an accuracy of at least ± 0,5%.
10. Oxygen meter for measuring oxygen concentration in air, intended for use in an explosive environment and with a measurement accuracy of at least ± 0,5%.
11. Electric flash detonators for use in explosive atmospheres.
12. Mine detonators or other direct current source intended for use in explosive atmospheres.
13. Aspiration psychrometer or other apparatus for measuring temperature and relative humidity. The temperature measurement accuracy shall be at least ± 1 ° C and the relative humidity shall be at least ± 2 per cent.
Preparation of tests
14. The test charge shall be made of charges of the same production series. The mass of the test charge shall be at least:
500 g for dust explosives,
600 g for Category I antigas explosives,
400 g for Category II and III gas explosives.
The mass of the charge shall be determined by the nominal weight of the charges. The dividing of the charges is permitted.
15. The category I dust and gas explosive test load shall be placed in a drill-hole to the bottom of the drill so that the individual markings touch each other and the ignited marking shall be the first from the mouth of the drill (the bottom of the detonator shall be directed towards the bottom of the drill). It is required that there is a free space without a seal of at least 100 mm in length between the mouth of the drill and the test charge.
16. The test charge of Category II and III anti-gas explosives is placed in the shaft of the edge of the cylinder so that the individual stickers touch each other, the centre of the charge was in the middle of the length of the gun, the igniter was the first from the head of the chamber and the bottom of the detonator pointed towards the aperture.
17. The tests shall be carried out at a temperature of 5 to 30 ° C and a relative humidity of 60 to 90%. These values shall be verified by measurements in the chamber before the charge is ignited.
18. The wear of the drill hole (increase of the original volume of the drill) shall not exceed:
25% - for tests for placing explosives on the market
50% - in control tests.
In the tests, the drill bar shall be rotated 120 ° after 1 / 3 of the specified limit wear of the drill. The volume of the drill shall be measured by means of water and measuring vessels.
19. The explosive mixture of coal dust with air is produced by igniting a 50 g explosive support device placed inside a paper bag with coal dust. The dust bag shall be hung in the longitudinal axis of the chamber so that its bottom is 500 ± 50 mm from the chamber ceiling and its lateral surface is 1000 ± 50 mm from the chamber front.
The mass of coal dust (mp) in grams is determined according to the relation:
mp = 300.V,
where V chamber volume (m3),
300 coefficient (g.m-3).
The auxiliary marker is made of the same explosive and production series as the main test charge. The delay between the auxiliary ignition and the main charge is between 1,000 and 1,100 ms.
20. The explosive mixture of methane with air is produced by pumping gas into the chamber part closed by the aperture and mixing it with air so that the concentration of methane is 9 ± 0,5% vol. and is the same throughout the chamber space. The concentration of oxygen in the explosive mixture shall be at least 18%. The concentration of methane and oxygen shall be verified by measuring before the charge ignites.
Testing and evaluation
21. The tests of rigorously safe explosives shall be evaluated by the Math-statistical method for evaluating test results for each explosive mixture separately.
22. When testing Category I anti-dust and gas explosives, the drill-hole with the charge shall be placed close to the opening from the outside of the chamber, Figure 1.
23. In the tests of Category II and III anti-gas explosives, the edge trigger with a charge shall be placed inside the chamber so that there is a distance of at least 1000 mm between the front surfaces of the enclosure and the face of the chamber or aperture, Figure 2.
24. When testing Category II anti-gas explosives, the edge trigger shall be rotated so that its walls are at an angle of 45 ° to the reflecting wall, Figure 3. The distance of the retro-reflecting wall from the top of the right angle of the impactor shall be 460 ± 10 mm, the vertical distance between the top of the right angle of the impactor and the ceiling of the chamber shall be 1 050 ± 50 mm and the vertical distance between the upper edge of the reflecting wall and the ceiling of the chamber shall be 110 ± 10 mm.
25. When testing Category III anti-gas explosives, the edge trigger shall be rotated so that its walls are at an angle of 0 ° and 90 ° to the reflecting wall, Figure 4. The distance of the retro-reflecting wall from the vertical edge of the canopy shall be 200 ± 10 mm, the vertical distance between the horizontal edge of the canopy and the ceiling of the chamber shall be 1 050 ± 50 mm and the vertical distance between the upper edge of the canopy shall be 110 ± 10 mm.
26. The explosive shall be considered satisfactory if the number of igniting of the explosive mixture is not more than the maximum permitted number of igniting according to Tables 1 and 2 in the Math-Statistical Test Method. Samples shall be required to comply with a test of at least P = 97,5% and p = 5%, for explosives placed on the market in accordance with Table 1 and for explosive exit tests in accordance with Table 2. A minimum probability of P = 97,5% and p ≤ 20% is required for periodic examination of the explosive according to Table 1.
Test record
27. The test record shall include:
(a) the nominal diameter and weight of the charges,
(b) the test method used;
(c) the mass of the test charge;
(d) wear of the drill hole in%;
(e) the number of tests and the number of ignites of the explosive mixture;
(f) nominal diameter of the test chamber;
(g) temperature and relative humidity in the chamber,
(h) the physico-chemical and granulometric composition of the coal dust;
(i) the concentration of methane in the explosion chamber at v / v%.
III. Revision of the resistance of hard-to-safe explosives to deflagration
General
The deflagration of mine-safe explosives (explosive explosive burning) is an explosive transformation whose speed is less than the speed of sound in the explosion. Deflation of thoroughly safe explosives is an undesirable phenomenon and in an environment with the possibility of explosive mixtures of gases or dust significantly increases the risk of ignition.
Deflagration resistance means the ability of explosive to withstand conditions favourable to deflagration.
METHOD A
Test substance
1. The charge of the test explosive, surrounded by coal dust and sealed in a steel tube with a nozzle for the leakage of gaseous residues, shall be ignited in the prescribed manner. After burning the ignition compound and extinguishing the ignited charge, the length of the unburned part of the explosive charge shall be determined by measuring.
Purpose and relevance of the test
2. The test shall determine whether the explosive tested is resistant to deflagration and complies with the conditions for assessing its applicability in shredding works in an environment with coal dust and methane.
Test equipment and equipment
3. For the test:
Steel tube (Figure 1) length 400 mm, outer diameter 57 mm, wall thickness 3 mm. On the front side, the tube has a steel cap with holes for hot spirals and for an escape nozzle, which is attached to the tube by a changing nut, on the other side, the tube is closed with a steel stopper with a thread.
Escape nozzle with hole
(a) 3,5 ± 0,1 mm in diameter, intended for testing high-safety gas explosives (Category II) - Figure 2a),
(b) a diameter of 2,0 ± 0,1 mm, is intended for the testing of high-safety gas explosives (Category III) - Figure 2b).
Coal dust, of a physical chemical composition:
volatile flammable material - not less than 28%
ash (A) - not more than 7%
water (W) - not more than 2,5%
with a granulometric composition of:
• Rest on nets with mesh diameter 0,5 mm - maximum 1%
• the rest on nets with mesh diameter 0,071 mm - not more than 25%.
The ignition component shall be prepared from 1 g of coal dust and 19 g of high-safety model gas explosive (Category III):
| nitroglyceroglykol (tj. směs nitroglycerinu a nitroglykolu 3 + 2) | 9,0 ± 0,1 % |
| dusičnan draselný | 58,6 ± 0,2 % |
| chlorid amonný | 31,0 ± 0,2 % |
| dřevěná moučka | 1,0 ± 0,1 % |
| silioxid | 0,4 ± 0,1 % |
The particle size of potassium nitrate and ammonium chloride used to prepare a model explosive shall not exceed 0,2 mm. The ignition component may be used within 3 months of the date of preparation.
The igniting spiral made of 250 mm resistance wire of 0,8 mm diameter, e.g. Ni / NiCr. The resistance wire is twisted into 7 turns with an inside diameter of 4 mm. The total resistance of the hot spiral is 0.9 to 1.0. The ends of the hot spiral are drawn in ceramic passages, which are sealed with plaster.
Silicon sand with particle size 0,25 to 0,50 mm.
Power supply with a current of at least 12 A, e.g. 24 / 220 V transfer transformer.
An empire with a range up to 15 A.
Ohmmeter with range 0 to 5.
The stopwatch.
1 - steel tube, 2 - steel cap of the front, 3 - steel stopper, 4 - changing nut, 5 - sealing, 6 - escape nozzle, 7 - ignition compound, 8 - hot spiral, 9 - charge of test explosive, 10 - coal dust, 11 - quartz sand
Fig. 1. Schematic of the assembly for deflagration test
Figure 2.
Preparation of the test charge
4. The charge of the test explosive 200 to 300 mm long consists of 1 to 2 stickers.
5. 20 mm explosive mass shall be removed from the forehead of one label. The length of the label so prepared for the test shall be measured at 3 different places with a millimetre gauge of steel with an accuracy of ± 0,5 mm, the arithmetic mean shall be calculated and the result shall be given in mm.
6. The collected part of the explosive shall be replaced by 20 g of ignition compound.
Test procedure
7. The required amount of dry quartz sand shall be poured into the steel tube closed with a steel stopper and a charge of the test explosive prepared in accordance with paragraphs 5 to 7 shall be placed on it and the ignition shall be folded upwards. The charge is filled with coal dust.
8. An escape nozzle with a hole corresponding to the relevant category of explosive test shall be inserted into the front cap with the hot spiral attached. The front cap shall be attached to the tube so that the hot spiral is fully immersed in the ignition compound. The assembly is closed by screwing the changing matrix.
9. The charge tube shall be placed in a protected position in a vertical position so that the front cap is directed upwards and the hot spiral pins are connected via the ampermeter to the inlet insulated conductors from the current source. A 12 A electrical current shall be switched on from the enclosure, which shall be allowed to flow through the hot spiral for 180 seconds and the test shall be observed. When the development of the gaseous fumes has ceased and the assembly has cooled, the tube shall be disassembled, the length of the non-burned label shall be measured after cleaning and it shall be determined whether more than 20 mm burn occurs at any point in the test label.
Test evaluation
10. The mathematical statistics rules applied in the Mathematical-statistical method of evaluation of results shall be used to evaluate the test.
The explosive is resistant to deflagration if, from the total number of test charges (n), the number of charges which have been fired above 20 mm (x) is lower than or equal to that indicated for parameters P = 90% and p = 20% in Table 1. It is required that the explosive does not show deflagration in 11 consecutive attempts with an escape nozzle of 3,5 mm in diameter for Category II explosives and an escape nozzle of 2 mm in diameter for Category III explosives.
Test record
11. The test record shall include:
(a) the diameter and mass of the explosives tested;
(b) the results of each determination;
(c) assessment of the test;
(d) any deviations of the test method.
METHOD B
Test substance
1. The load of the test explosive, located in a closed drill of a steel cylinder, shall be exposed to a heat and pressure exposure of the gaseous products, which shall be released by burning the dust-free label placed in the drill at a certain distance from the explosive charge. The heat and pressure exposure intensity is changed by the weight of dust free. The dust igniter is realized by the electric thumb. After exposure, the drill shall be opened and visually assessed whether the explosive charge has been ignited and burned.
Purpose and relevance of the test
2. The test shall determine whether the explosive tested is resistant to deflagration and complies with the conditions for assessing its applicability in shredding works in an environment with the presence of coal dust and methane.
3. The test can determine the actual level of antideflationary properties of explosive.
Test equipment and equipment
4. For the test:
(a) The test device - deflagration device, Figure 3, consists of a steel forging of a cylindrical shape of steel of 12.0600.4 with a diameter of not less than 220 mm and a length of 1,450 ± 25 mm, fitted along the whole length with a bore in the cylinder axis. The diameter of the bore is 42 mm. The drill is sealed from both sides with special closures. It consists of a steel flange and a sealing tapered liner. The flange is drawn to the front of the 6 screws. For the perfect seal of the drill, a seal (e.g. klingerite, teflon) is inserted between the face of the hole and the sealing cone. The seal used shall withstand high temperature and pressure from deflagration. On one side of the drill, the sealing tapered insert is equipped with passages to connect the electric thumb. On the other side of the drill, the sealing conical insert is equipped with an insurance membrane to release the pressure in the event of deflation in detonation. The drill is equipped with two holes, one at 200 mm from the head of the hole, used to mount the pressure sensor and the other at 300 mm from the same forehead, with an end of the high pressure needle valve, which is used to release pressure after the test is completed.
Sign in for notes, favorites and notifications
Regulation Information
| Citation | Decree No 293 / 2003 Coll., on the closer conditions and characteristics of explosives intended for use in or in risk environments and on checking the properties of such explosives |
|---|---|
| Regulation Type | Order |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 08.09.2003 |
|---|---|
| Effective from | 01.10.2003 |
| Effective until | - |
| Status | Valid |
The regulation text is for informational purposes only.
Comments 0