US3374127A - Compressed metal containing ternary explosive composition - Google Patents
Compressed metal containing ternary explosive composition Download PDFInfo
- Publication number
- US3374127A US3374127A US570624A US57062466A US3374127A US 3374127 A US3374127 A US 3374127A US 570624 A US570624 A US 570624A US 57062466 A US57062466 A US 57062466A US 3374127 A US3374127 A US 3374127A
- Authority
- US
- United States
- Prior art keywords
- explosive
- cartridge
- explosive composition
- electrodes
- composition
- 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.)
- Expired - Lifetime
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
- F42D1/04—Arrangements for ignition
- F42D1/045—Arrangements for electric ignition
- F42D1/05—Electric circuits for blasting
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B23/00—Compositions characterised by non-explosive or non-thermic constituents
- C06B23/009—Wetting agents, hydrophobing agents, dehydrating agents, antistatic additives, viscosity improvers, antiagglomerating agents, grinding agents and other additives for working up
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B25/00—Compositions containing a nitrated organic compound
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B31/00—Compositions containing an inorganic nitrogen-oxygen salt
- C06B31/28—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B3/00—Blasting cartridges, i.e. case and explosive
- F42B3/10—Initiators therefor
- F42B3/12—Bridge initiators
- F42B3/128—Bridge initiators characterised by the composition of the pyrotechnic material
Definitions
- the detonation of an explosive charge is generally brought about by a primer or detonator, which in most cases consists of a small quantity of a very sensitive primary explosive, such as mercury fulminate, lead nitride or the like.
- the primer is necessarily sensitive to shocks, heat, or weak electric currents and always represents a critical feature of an explosive assembly. For this reason, the statutes in numerous countries (for instance, in France) prohibit the storage of detonators close to explosive charges and vigorously forbid the storage of primed charges.
- Another object of the invention is the provision of an explosive composition permitting the construction of a single cartridge, instead of a cartridge and a primer.
- a further object of the present invention is the provision of an explosive composition to use in the production of a cartridge which is not sensitive to shocks.
- a still further object of this invention is the provision of a cartridge combining the functions of an explosive material and a primer, which cartridge is simple in construction and safe in operation.
- FIG. 1 is a sectional view of an explosive cartridge embodying the principles of the present invention.
- FIG. 2 is a sectional view of a cartridge constructed in accordance with the teachings of the prior art.
- FIG. 3 is an electrical circuit diagram with a sample of the composition being tested
- the invention consists of an explosive composition made up of a known secondary explosive material mixed with a substance for lowering the electrical resistivity of the mixture and with an oxidizable and electrically conductive material having an intense heat release during combustion for initiating detonation by burning Within the charge.
- a suitable explosive cartridge would be detonated by an electrical discharge acting upon an explosive composition which in the compact state would have an electric resistivity which, although allowing the passage of an electric current, would be sufliciently high to require the application of a voltage greater than 2000 volts to produce a current density between 0.1 and 1000 amp./c1n.
- the voltage to be applied to cause the explosion of the cartridge would be in the order of 5000 to 50,000 volts and preferably 10,000 to 20,000 volts.
- the secondary explosive material used in the car tridge may be nitroglycerine, pentaerythritol tetranitrate, cyclotrimethylene-trinitramine (Hexogen), trinitrotoluene (Tolite or TNT), ammonium nitrate, or nitrocotton.
- the substances for lowering the resistivity of the explosive composition in the compact state may be one of various solid substances which are compatible with the secondary explosive material and which have a relatively low electric resistivity.
- these substances are graphite, naphthalene, certain metal sulfides, such as iron disulfide. These substances are used in the form of fine powders.
- the oxidizable, electrically conductive and strongly exothermic material is selected from strongly electropositive metals in powder form.
- the metals of Groups II to VA of the periodic system, alloys formed of these metals or alloys of these metals with metals of other groups give good results.
- Especially suitable for the purposes of the invention are: magnesium, aluminum, calcium, strontium, barium, zirconium, beryllium, antimony, silicon, ferrosilicon, and various magnesium alloys.
- These oxidizable materials are preferably employed in the form of very fine powders, with an average particle size in the range from 0.01 to 1 mm.
- the proportion of resistivity-lowering substances and of the oxidizable materials incorporated into the explosive may vary in accordance with the electrical and chemical properties of the secondary explosive concerned.
- the proportion generally lies in the range between 1 and 20%, calculated on the weight of the mixture. In most cases, the proportion of each of these additives is between 3 and 10% by weight.
- the mixture of these materials must be as homogeneous as possible.
- the composition is compressed to obtain a compact mass, with a zone for accommodating the firing electrodes.
- the compression is generally effected with 10 to 100 leg/cm. and in most cases with 20 to 60 kg./cm.
- the mechanism of action of the oxidizable metal powder appears to be that of a firing relay: when two grains of this metal are traversed by an electric current, they become poles between which a small electric arc is established. These grains then burn by drawing oxygen from the explosive and thus initiate the detonation.
- the voltage to be employed for detonating the new compositions can be predetermined by the nature and the quantities employed of the above-mentioned materials, so that the required safety margin can be established. It is possible to prepare charges which will explode only at 5000 v., 10,000 v. or 20,000 v. or at any other predetermined voltage. For this purpose, it suffices to confer to the explosive charge the appropriate electrical resistivity.
- pure compacted penthrite has a resistivity of the order of 10 ohms/cm, While its resistivity falls to 1l000 ohms/cm. when mixed with 2% flaky graphite and magnesium powder; this resistivity value can be respectively reduced or increased by increasing or diminishing the graphite content.
- the compressed compositions according to the invention have resistivities below ohms./cm., preferably not exceeding 10 ohms/cm.
- a cartridge made in accordance with the teachings of the invention contains a charge made up of the explosive composition described above.
- Two diametrically opposite electrodes are fixed in the charge and the extremities project beyond the charge. These external ends of the electrodes are provided with means for connecting them to conductor wires coming from a source of electrical energy.
- the distance between the electrodes may vary greatly, but in most cases it is between 10 and 80 mm., more especially 30 mm.
- a circuit for applying the voltage to the cartridge electrodes may consist of a capacitor in series with the conductors connecting the poles of a voltage source to the cartridge electrodes; the capacitor can be alternately connected with the voltage source and with the electrodes by means of a reversing switch.
- the cylinder 1 represents a cartridge made up of a compact mass of secondary explosive containing about 10% of a resistivity-lowering substance and an oxidizable material, specifically a metal powder. Electrodes 2 and 2 are inserted into the explosive charge; the latter are simply uncovered metal wires such as copper. Electric leads 3 and 3' extend away from the cartridge and the electrodes.
- FIG. 2 a cartridge 4 of the old type, containing a secondary explosive.
- a conventional electrical detonator 5 contains a primer, i.e., a primary explosive, which is not present in the arrangement of FIG. 1, accord-ing to the invention. Because of the previously-described danger and by virtue of the existing regulations, when the cartridge 4 is intended for use in high-capacity blasting, as in mines or quarries, the detonator 5 is stored separately from the cartridge 4 and is placed within the latter only at the moment of use.
- a DC. voltage source 6 is connected to a switch 7, whose movable arms are connected to a capacitor 8. At the same time, the leads 3 and 3 coming fro-m the electrodes 2 and 2' are connected to the corresponding terminals of the switch 7. In this manner, a strong electrical discharge, which is far more powerful than those hitherto employed, is applied to the electrodes through the capacitor 8.
- a DC. voltage source 6 of 10,000 volts and a capacitor 8 of 2 microfarad may be employed.
- Electrical energy of the order of 100 joules can be delivered in this manner, at a high voltage, where as the blasting boxes with magneto and capacitor discharge, used for firing by conventional electrical detonators, can deliver only 1 to 10 joules, at a voltage of the order of 500 volts in general, and a maximum voltage of 2000 volts.
- the device made in accordance with the invention provides a very substantial safety factor, since this new explosive composition cannot explode either under the effects of an industrial A.C. voltage of 220 or 380 volts, nor under the effects of a voltage coming from a battery or a bank of accumulators.
- the new composition is equally insensitive to induction effects due to a radio transmitter, even if the latter is powerful and located close to the explosive. It is insensitive to natural electrostatic discharges and in some cases also to violent mechanical shocks.
- the electrical detonators or primers now in general use are very sensitive to all these effects.
- Example 1 72 parts by weight of PETN powder (pentaerythritol tetranitrate) were coated with 20 parts by weight of molten TNT (trinitrotoluene). To this, 3 parts of graphite flakes and 5 parts magnesium powder were added, the mean particle size of the magnesium powder being 0.074 mm. The mixture was well homogenized, after which solid cylindrical cartridges (each weighing about 50 g.) were produced by pressing at 20 kg./cm. The cartridges were about 4 cm. high and had a diameter of about 3 cm.
- Example 2 A cartridge similar to that of Example 1 was prepared with 82 parts by weight of PETN and 10 parts TNT, the proportions of the additives being the same as in the previous example. The cartridges thus obtained exploded in the same conditions as those in Example 1.
- Examples 3-13 Cartridges similar to those in Example 1 were prepared by mixing various secondary explosives with 7% aluminum or magnesium powder, the particle dimensions of which did not exceed 0.074 mm, and with 3% carbon powder. These mixtures were compressed at 50 kg./cm. The cartridges were then tested for detonation with the arrangement of FIG. 3, using cylindrical electrodes of 30 mm. diameter, the bases of which were pressed against the base surfaces of the cartridge.
- the following table indicates the voltages at which detonation occurred and the capacitances of the capacitor 8 for each of the explosive compositions tested.
- An explosive composition consisting essentially of a compressed mixture of from 1 to 20% of a substance for lowering the electrical resistivity of the mixture, from 1 to 20% an oxidizable substance, and the rest a secondary explosive material, said secondary explosive material being selected from the group consisting of pentaerythritoltetranitrate, cyolotrimethylene-trinitramine, trinitrotoluene, ammonium nitrate, and nitrocotton, said substance for lowering the electric resistivity being selected from the group consisting of graphite, naphthalene and metal sulphides, and said oxidizable substance being selected from the class consisting of finely powdered magnesium, aluminum, calcium, strontium, barium, zirconium, beryllium, antimony, silicon, and ferrosilicon.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Automotive Seat Belt Assembly (AREA)
- Air Bags (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR28241A FR1457461A (fr) | 1965-08-13 | 1965-08-13 | Nouvelle composition explosive |
Publications (1)
Publication Number | Publication Date |
---|---|
US3374127A true US3374127A (en) | 1968-03-19 |
Family
ID=8586594
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US570624A Expired - Lifetime US3374127A (en) | 1965-08-13 | 1966-08-05 | Compressed metal containing ternary explosive composition |
Country Status (5)
Country | Link |
---|---|
US (1) | US3374127A (fr) |
DE (1) | DE1571238A1 (fr) |
FR (1) | FR1457461A (fr) |
GB (1) | GB1159975A (fr) |
NL (1) | NL6611288A (fr) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3455750A (en) * | 1967-12-29 | 1969-07-15 | Hercules Inc | Nonaqueous inorganic oxidizer salt blasting compositions containing silicon component of particular size |
US3959041A (en) * | 1973-04-03 | 1976-05-25 | The United States Of America As Represented By The Secretary Of The Army | Illumination and incendiary composition for explosive munitions |
US4070970A (en) * | 1975-05-14 | 1978-01-31 | The Secretary Of State For Industry In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain & Northern Ireland | Electro-explosive igniters |
US20030075068A1 (en) * | 2001-10-23 | 2003-04-24 | Kim Chang Sun | Structure of capsule for rapidly expanding metallic mixture |
EP1323596A1 (fr) * | 2001-12-25 | 2003-07-02 | Takata Corporation | Initiateur et générateur de gaz |
US20040231546A1 (en) * | 2003-05-23 | 2004-11-25 | Ofca William W. | Safe electrical initiation plug for electric detonators |
EP1742009A1 (fr) * | 2005-07-05 | 2007-01-10 | Institut Franco-Allemand de Recherches de Saint-Louis | Composition explosive pour allumage thermique par source laser et son dispositif d'amorcage |
NO20151689A1 (en) * | 2015-12-09 | 2017-06-12 | Interwell P&A As | Ignitor, system and method of electrical ignition of exothermic mixture |
CN110686567A (zh) * | 2018-07-04 | 2020-01-14 | 南京理工大学 | 一种利用功能化碳纤维制备无桥电火工品的方法 |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE8602984D0 (sv) * | 1986-07-04 | 1986-07-04 | Intermatch Ab | Tendsats till pyrotekniska stryktendstickor |
GB9027203D0 (en) * | 1990-12-14 | 1991-04-24 | Eev Ltd | Firing arrangements |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US770046A (en) * | 1904-03-07 | 1904-09-13 | Roth Fa G | Explosive. |
US2754755A (en) * | 1950-12-29 | 1956-07-17 | Olin Mathieson | Cored ammonium nitrate explosive cartridge |
US2836484A (en) * | 1955-05-04 | 1958-05-27 | Reynolds Metals Co | Aqueous metal powder explosive |
US2887370A (en) * | 1957-02-12 | 1959-05-19 | Reed E Donnard | Non-corrosive percussion primer material |
US2954284A (en) * | 1958-02-13 | 1960-09-27 | Ohio Commw Eng Co | Fuel comprising a mixture of ammonium nitrate and metal particles |
US2970047A (en) * | 1958-06-05 | 1961-01-31 | Thomas Q Ciccone | Conductive priming mixture |
US2996007A (en) * | 1958-08-25 | 1961-08-15 | Philip J Franklin | Explosive train |
US3004842A (en) * | 1958-02-04 | 1961-10-17 | Canadian Ind | Ammonium nitrate explosives and their manufacture |
US3090310A (en) * | 1960-05-04 | 1963-05-21 | George W Peet | Conductive explosive primer mixture and device |
US3156186A (en) * | 1961-03-17 | 1964-11-10 | Gen Precision Inc | Ammonium nitrate-aluminum explosive |
US3160537A (en) * | 1961-10-12 | 1964-12-08 | Catalyst Research Corp | Heating composition |
US3278353A (en) * | 1956-12-03 | 1966-10-11 | Remington Arms Co Inc | Ammunition priming composition comprising aromatic hydroxy compounds |
-
1965
- 1965-08-13 FR FR28241A patent/FR1457461A/fr not_active Expired
-
1966
- 1966-08-05 GB GB35138/66A patent/GB1159975A/en not_active Expired
- 1966-08-05 US US570624A patent/US3374127A/en not_active Expired - Lifetime
- 1966-08-11 NL NL6611288A patent/NL6611288A/xx unknown
- 1966-08-12 DE DE19661571238 patent/DE1571238A1/de active Pending
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US770046A (en) * | 1904-03-07 | 1904-09-13 | Roth Fa G | Explosive. |
US2754755A (en) * | 1950-12-29 | 1956-07-17 | Olin Mathieson | Cored ammonium nitrate explosive cartridge |
US2836484A (en) * | 1955-05-04 | 1958-05-27 | Reynolds Metals Co | Aqueous metal powder explosive |
US3278353A (en) * | 1956-12-03 | 1966-10-11 | Remington Arms Co Inc | Ammunition priming composition comprising aromatic hydroxy compounds |
US2887370A (en) * | 1957-02-12 | 1959-05-19 | Reed E Donnard | Non-corrosive percussion primer material |
US3004842A (en) * | 1958-02-04 | 1961-10-17 | Canadian Ind | Ammonium nitrate explosives and their manufacture |
US2954284A (en) * | 1958-02-13 | 1960-09-27 | Ohio Commw Eng Co | Fuel comprising a mixture of ammonium nitrate and metal particles |
US2970047A (en) * | 1958-06-05 | 1961-01-31 | Thomas Q Ciccone | Conductive priming mixture |
US2996007A (en) * | 1958-08-25 | 1961-08-15 | Philip J Franklin | Explosive train |
US3090310A (en) * | 1960-05-04 | 1963-05-21 | George W Peet | Conductive explosive primer mixture and device |
US3156186A (en) * | 1961-03-17 | 1964-11-10 | Gen Precision Inc | Ammonium nitrate-aluminum explosive |
US3160537A (en) * | 1961-10-12 | 1964-12-08 | Catalyst Research Corp | Heating composition |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3455750A (en) * | 1967-12-29 | 1969-07-15 | Hercules Inc | Nonaqueous inorganic oxidizer salt blasting compositions containing silicon component of particular size |
US3959041A (en) * | 1973-04-03 | 1976-05-25 | The United States Of America As Represented By The Secretary Of The Army | Illumination and incendiary composition for explosive munitions |
US4070970A (en) * | 1975-05-14 | 1978-01-31 | The Secretary Of State For Industry In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain & Northern Ireland | Electro-explosive igniters |
US20030075068A1 (en) * | 2001-10-23 | 2003-04-24 | Kim Chang Sun | Structure of capsule for rapidly expanding metallic mixture |
US6759798B2 (en) * | 2001-10-23 | 2004-07-06 | Chang Sun Kim | Structure of capsule for rapidly expanding metallic mixture |
EP1323596A1 (fr) * | 2001-12-25 | 2003-07-02 | Takata Corporation | Initiateur et générateur de gaz |
US20040231546A1 (en) * | 2003-05-23 | 2004-11-25 | Ofca William W. | Safe electrical initiation plug for electric detonators |
EA009339B1 (ru) * | 2003-05-23 | 2007-12-28 | Дино Нобель, Инк. | Безопасная электрическая инициирующая свеча для электрических детонаторов |
EP1742009A1 (fr) * | 2005-07-05 | 2007-01-10 | Institut Franco-Allemand de Recherches de Saint-Louis | Composition explosive pour allumage thermique par source laser et son dispositif d'amorcage |
FR2888234A1 (fr) * | 2005-07-05 | 2007-01-12 | Saint Louis Inst | Composition energetique dopee optiquement |
US20070113941A1 (en) * | 2005-07-05 | 2007-05-24 | Deutsch-Franzosisches Forschungsinstitut Saint-Louis | Optically doped energetic igniter charge |
US7784403B2 (en) | 2005-07-05 | 2010-08-31 | Deutsch-Franzosisches Forschungsinstitut | Optically doped energetic igniter charge |
NO339580B1 (no) * | 2005-07-05 | 2017-01-09 | Deutsch Franzoesisches Forschungsinstitut Saint Louis | Optisk dopet energirik tennsats |
NO20151689A1 (en) * | 2015-12-09 | 2017-06-12 | Interwell P&A As | Ignitor, system and method of electrical ignition of exothermic mixture |
CN110686567A (zh) * | 2018-07-04 | 2020-01-14 | 南京理工大学 | 一种利用功能化碳纤维制备无桥电火工品的方法 |
Also Published As
Publication number | Publication date |
---|---|
FR1457461A (fr) | 1966-01-24 |
NL6611288A (fr) | 1967-02-14 |
GB1159975A (en) | 1969-07-30 |
DE1571238A1 (de) | 1971-02-18 |
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