GB2100845A - Protective sheathing for blasting materials - Google Patents
Protective sheathing for blasting materials Download PDFInfo
- Publication number
- GB2100845A GB2100845A GB08119781A GB8119781A GB2100845A GB 2100845 A GB2100845 A GB 2100845A GB 08119781 A GB08119781 A GB 08119781A GB 8119781 A GB8119781 A GB 8119781A GB 2100845 A GB2100845 A GB 2100845A
- Authority
- GB
- United Kingdom
- Prior art keywords
- protective
- sheathing
- aqueous gel
- damp
- fire
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000001681 protective effect Effects 0.000 title claims abstract description 57
- 239000000463 material Substances 0.000 title claims abstract description 25
- 238000005422 blasting Methods 0.000 title claims abstract description 14
- 239000002360 explosive Substances 0.000 claims abstract description 19
- 239000002817 coal dust Substances 0.000 claims abstract description 13
- 238000005065 mining Methods 0.000 claims abstract description 11
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims abstract description 8
- 239000000347 magnesium hydroxide Substances 0.000 claims abstract description 8
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims abstract description 8
- 239000000654 additive Substances 0.000 claims abstract description 6
- 230000000996 additive effect Effects 0.000 claims abstract description 6
- 239000010451 perlite Substances 0.000 claims abstract description 6
- 235000019362 perlite Nutrition 0.000 claims abstract description 6
- 239000000499 gel Substances 0.000 claims description 24
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 24
- 238000001816 cooling Methods 0.000 claims description 12
- 230000000694 effects Effects 0.000 claims description 12
- 238000004880 explosion Methods 0.000 claims description 12
- 239000000126 substance Substances 0.000 claims description 12
- 238000005474 detonation Methods 0.000 claims description 10
- 150000003839 salts Chemical class 0.000 claims description 10
- 239000003245 coal Substances 0.000 claims description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 4
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 239000011253 protective coating Substances 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 241001674808 Biastes Species 0.000 claims description 2
- -1 NaCI Chemical class 0.000 claims description 2
- 235000010216 calcium carbonate Nutrition 0.000 claims description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 230000008030 elimination Effects 0.000 claims description 2
- 238000003379 elimination reaction Methods 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- 238000002360 preparation method Methods 0.000 claims description 2
- 235000012254 magnesium hydroxide Nutrition 0.000 claims 4
- 229960000816 magnesium hydroxide Drugs 0.000 claims 4
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
- F42D1/08—Tamping methods; Methods for loading boreholes with explosives; Apparatus therefor
- F42D1/24—Tamping methods; Methods for loading boreholes with explosives; Apparatus therefor characterised by the tamping material
- F42D1/28—Tamping with gelling agents
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Fire-Extinguishing Compositions (AREA)
- Fireproofing Substances (AREA)
Abstract
An anti-fire-damp and coal dust explosion-proof protective covering for blasting materials, particularly for use in underground mining, contains an aqueous gel and magnesium hydroxide as an additive, and preferably contains perlite. The thus produced protective covering is more pliable than known ones, is less prone to damage and is chemically more stable, while at the same time improving the detonative properties of the explosive material protected by it.
Description
SPECIFICATION
Anti-fire-damp and coal dust explosion-proof protective sheathing for blasting materials
The invention concerns an anti-fire-damp and coal dust explosion-proof protective sheathing for blasting materials, particularly for use in undergound mining.
In underground mining, particularly in underground coal mining, blasting operations represent the potentially most dangerous source of hazard because detonation of the explosives may also explode coal-dust and methane gas. A great number of coal mines (in Hungary, 75%) belong the category of mines dangerous as regards fire-damp and coal-dust.
So-called anti-fire-damp explosives are already known, but they provide, only relative (not absolute) safety which can be achieved, according to the present state of art, in two ways: either by mixing so-called cooling salts with the explosive or by wrapping a protective casing around the explosive substance.
The cooling salts (e.g. NaCI, CaCO3, etc.) reduce the probability of an explosion of methane and coal-dust by a cooling effect exerted during detonation. Their application has, however, a negative effect, since they considerably reduce the operative efficiency of the biasting material.
The protective casings or sheaths reduce the probability of an explosion by isolating the explosive from its surroundings. These are the socalled active protective sheaths, consisting of an
explosive (blasting) material and cooling salts, and there are also the so-called passive protective
sheaths, consisting generally, of cooling salts. In
the active protective sheathing the detonation of
the sheathing material pulverizes the cooling salts, thus increasing the protective effect. These
already known protective casings or sheaths are
rigid and damage-prone. Damage to the protective
sheath in effect eliminates the protective effect.
Aqueous protective coatings are also known.
These provide a high degree of safety against fire
damp explosion, but their preparation is difficult
and cumbersome due to the fact that water can
escape even through the slightest crack.
To eliminate this drawback protective coatings
made of aqueous gels have been introduced.
Although these are less danger-prone, water does
not escape from them and, within certain
limitations, they provide a satisfactory protective
effect, they are not sufficiently plastic or pliable;
thus e.g. on being placed in a bore-hole (biast
hole) the provision of a protective sheath of
uniform thickness is problematic. Afurther particular disadvantage of the known protective
sheathings made of aqueous gel is, that, due to
the burning-up (combustion) of the organic
substances contained therein, an exothermic
chemical reaction takes place which may cause
explosion of the methane gas. Furthermore, the
already known protective sheathings containing
aqueous gel have insufficient chemical stability.
The invention aims at the elimination or reduction of the disadvantages of known protective sheathings containing aqueous gel, and at providing protective sheathings of improved plasticity and chemical stability, compared with known protective sheathings of aqueous gel; furthermore, it is sought to provide coatings that during detonation do not exert an exothermic effect that would be dangerous from the point of view of a fire-damp explosion.
The invention is based on the discovery that magnesium hydroxide introduced into the aqueous gel forming the protective sheathing produces an endothermic effect which can compensate for or out the exothermic effect occurring during the combustion of an organic substance contained in the aqueous gel, thus reducing the danger of a blast and at the same time improves the mechanical and detonative properties of the blasting material protected by the sheathing.
An objective of the invention is accordingly to provide an anti-fire-damp and coal-dust explosionproof protective sheathing for explosive materials, particularly for applications in underground mining, which contains an aqueous gel and, according to the invention, magnesium hydroxide as additive material. In a preferred embodiment of the invention the aqueous gel contains perlite.
The protective sheathing containing aqueous gel according to the invention is more pliable than the known ones, is less prone to damage and is chemically more stable. According to our experience, the changes occurring in the detonative properties of the protective sheathing according to the invention remain within a limit of + 10% after a storage time of six months. The protective sheathing according to the invention somewhat surprisingly also improves the detonative properties of the explosive material protected by it, i.e. it increases the rate of the detonation by approximately 1 5-20% consequently increasing the working potential and the shattering power by approximately 3050%.
According to the tests carried out in experimental tunnels or adits, 200 g explosive material provided with a 3-6 mm protective sheathing, according to the invention, does not cause explosion of fire-damp containing 812% methane gas, even when it was suspended in the interior of the adit or tunnel.
By varing the quantity of the thermally neutral perlite introduced as an additive substance to the magnesium hydroxide a protective sheathing can be produced which has a consistency satisfying all current requirements without affecting the advantageous properties of the protective sheathing according to the invention.
1. Anti-fire-damp and coal dust-proof protective covering for blasting materials, particularly for use in underground mining, wherein said covering contains an aqueous gel
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (3)
1. Anti-fire-damp and coal dust-proof protective covering for blasting materials, particularly for use in underground mining, wherein said covering contains an aqueous gel and said gel contains magnesium-hydroxide as an additive.
2. A covering according to claim 1 wherein the aqueous gel contains perlite.
3. A covering according to claim 1 or claim 2 substantially as herein particularly described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08119781A GB2100845A (en) | 1981-06-26 | 1981-06-26 | Protective sheathing for blasting materials |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08119781A GB2100845A (en) | 1981-06-26 | 1981-06-26 | Protective sheathing for blasting materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2100845A true GB2100845A (en) | 1983-01-06 |
Family
ID=10522837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08119781A Withdrawn GB2100845A (en) | 1981-06-26 | 1981-06-26 | Protective sheathing for blasting materials |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2100845A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2121459A (en) * | 1982-06-04 | 1983-12-21 | Mecseki Szenbanyak | Method and apparatus for breaking mineral deposits |
| US4543872A (en) * | 1983-08-08 | 1985-10-01 | Graham Kenneth J | Blast attenuator |
| WO2005052500A1 (en) * | 2003-11-24 | 2005-06-09 | Oztech Pty Ltd As Trustee Of The Oztech Trust | Pressure impulse mitigation |
| WO2006114597A3 (en) * | 2005-04-28 | 2006-12-14 | Oztech Pty Ltd | Pressure impulse mitigation |
| US9175931B2 (en) | 2005-05-23 | 2015-11-03 | Flexiblast Pty Ltd. | Pressure impulse mitigation |
| CN112716080A (en) * | 2021-02-02 | 2021-04-30 | 北京大学深圳医院 | Health gauze mask for preventing disease |
-
1981
- 1981-06-26 GB GB08119781A patent/GB2100845A/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2121459A (en) * | 1982-06-04 | 1983-12-21 | Mecseki Szenbanyak | Method and apparatus for breaking mineral deposits |
| US4543872A (en) * | 1983-08-08 | 1985-10-01 | Graham Kenneth J | Blast attenuator |
| WO2005052500A1 (en) * | 2003-11-24 | 2005-06-09 | Oztech Pty Ltd As Trustee Of The Oztech Trust | Pressure impulse mitigation |
| AU2004293662B2 (en) * | 2003-11-24 | 2010-03-25 | Flexiblast Pty Limited | Pressure impulse mitigation |
| US7832324B2 (en) | 2003-11-24 | 2010-11-16 | Flexiblast Pty Ltd. | Fire mitigation |
| US7861637B2 (en) | 2003-11-24 | 2011-01-04 | Flexiblast Pty Ltd | Pressure impulse mitigation |
| WO2006114597A3 (en) * | 2005-04-28 | 2006-12-14 | Oztech Pty Ltd | Pressure impulse mitigation |
| US8828134B2 (en) | 2005-04-28 | 2014-09-09 | Flexiblast Pty Ltd. | Pressure impulse mitigation |
| US9175931B2 (en) | 2005-05-23 | 2015-11-03 | Flexiblast Pty Ltd. | Pressure impulse mitigation |
| CN112716080A (en) * | 2021-02-02 | 2021-04-30 | 北京大学深圳医院 | Health gauze mask for preventing disease |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |