Classifications

• • 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
  • C06B23/04—Compositions characterised by non-explosive or non-thermic constituents for cooling the explosion gases including antifouling and flash suppressing agents
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S149/00—Explosive and thermic compositions or charges
  • Y10S149/11—Particle size of a component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S149/00—Explosive and thermic compositions or charges
  • Y10S149/11—Particle size of a component
  • Y10S149/112—Inorganic nitrogen-oxygen salt

Definitions

• detonating explosives of generally low power, characteristics comprising ammonium nitrate and a self-explosive sensitizer include a .fuel comprising in association at non-deliquescent' ammonium salt of the kind herein defined and. an insoluble metal carbonate.
• mixtures of the ammonium salt of the inorganic acid as aforesaid'and the insoluble metal carbonate in the proportions theoretically required for their metathetical transformation into ammonium carbonate and a salt of the metal react with the ammonium nitrate without flame and help to quench the flame from the self expl'o sive sensitizer, as wel1 as producing power gases.
• non-deliquescent oxidizable ammonium salt there may be conveniently employed for instance ammonium sulphate, phosphate or chloride.
• insoluble metal carbonate there may be used any natural or artificial form of calcium carbonate, magnesium carbonate, barium carbonate, iron carbonate or the like, for instance, limestone fines, chalk, dolomite fines, witherite fines, siderite fines or marble fines.
• the size and shape of the particles of the ingredients are not without" influence on the sensitiveness characteristics of the composition, especially when the self-explocarbonate and the non-deliquescent oxidizable ammonium salt may be used as individual materials, of which the particles are brought into simple admixture with one another and with the self-explosive ingredients, but it is also possible to use composite granules prepared for instance in thewet way or by fusion, and containing the ammonium nitrate and non-deliquescent oxidizable sive ingredient is one capable of absorption, 1. e.
• Every three gram atoms of available oxygen are capable of oxidizing amounts of a mixture of insoluble metal carbonate and non-delinquescent oxidizable ammonium salt as aforesaid equivalent to 1 gram molecule of normal ammonium carbonate; so that when the other ingredients of the explosive neither contain nor consume available oxygen, an oxygen balanced explosive is obtained by the use of amounts of the insoluble metal carbonate and the non-deliquescent oxidizable ammonium salt as aforesaid theoretically equivalent to 1 gram molecule of normal ammonium carbonate for every 3 gram molecules ammonium nitrate.
• Reasonably small variations from Zero oxygen value on either side as in ordinar explosive compositions are of course permissible.
• insoluble metal carbonate or other flame quenching or cooling ingredients it is sometimes desirable to include such excess of insoluble metal carbonate or other flame quenching or cooling ingredients, as when, for instance an explosive of especially low velocity of detonation, low power and high safety characteristics is required; or when a gelatine or semi-gelatine explosive of good safety characteristics is required, since in this case the attainment of the requisite consistency necessitates the use of higher proportions of liquid selfexplosive ingredients than need be present in the case of powder explosive compositions.
• an acid buffer salt as for example sodium or ammonium dihydrogen phosphate
• a non-alkaline mixture of buffer salts as for example one or more alkali metal dihydrogen orthophosphates and one or more dialkali metal orthophosphates in such relative proportions as to give neutral mixtures of these salts.
• a suitable buffersalt may be included in the mixture in order to minimize the alkalinity, for instance ammonium dihydrogen phosphate.
• soluble nitrocellulose may be defined as the prod-' uct of purified cotton cops nitratedby the pot process to a nitrogen content of 11.95 to 12.25 per cent.
• the product is at least 95 per cent soluble in an ether-alcohol solution, and has av viscosity of 10 0 to 300 C. G. S. in solution of 3; gIIlS. in 100 ml. acetone 95 per cent at 20 C.
• ammonium nitrate nearly all passes a 20 mesh British Standard Specification screen, roughly 45 per cent being retained on a 40 mesh,
• Example 3 43.2 parts ammonium nitrate, 18.9 parts ammonium chloride and 17.9 parts limestone fines of the same grists as in Example 1 are mixed with parts pentaerythritol tetranitrate.
• the resulting powder explosive When cartridged at a density of 0.99 the resulting powder explosive is sensitive to initiation by a small commercial detonator, and has a velocity of about 2,500 meters per second and a power of about 53 per cent of that of blasting gelatine.
• Example 4 32.4 parts ammonium nitrate, 14.2 parts ammonium chloride and 28.4 parts limestone fines, all of the same grists as in Example 1, are intimately mixed in a McRoberts mixer into parts of a jelly made from an 80:20 mixture of nitroglycerine and ethylene glycol dinitrate and blasting soluble nitrocellulose, containing 9'7 per cent of the liquid nitric esters.
• the resulting safety gelatine explosive can be cartridged by extrusion. When tested a few days after its manufacture a 1%" x 8" cartridge could be detonated by a small commercial detonator, and in the double cartridge gap test the detonation was transmitted across a gap of about 6 /2 inches.
• the density was 1.74 grams per cubic centimetre and the velocity of detonation was about 1,800 metres per second.
• the cartridges failed to give ignition in gallery tests conducted as prescribed in the official gallery tests, and in the tests which the cartridges were suspended in the methaneair mixture the charge limit was about 14 ozs.
• the power of the explosive was about 46 per cent of that of blasting gelatine.
• Example 5 A strong solution in hot water was formed from 45.2 parts ammonium nitrate, 25.0 parts ammonium sulphate and 1.0 part ammonium dihydrogen phosphate. 18.5 ⁇ parts; limestone fines of the same grist as that usedin' Example 1- v were suspended in thesolution, and the mixture was evaporated to drynessandgranulated; by
• Example 6 The materials used and the procedure were the same as in Example 5, except that the ratio of the graulated mixture of salts to the jelly was increased to :5. When cartridged to a bulk density of 0.95 and tested after a few days it was sensitive to initiation by a small commercial detonator. The velocity of detonation was about 1,400 metres per second.
• Example 7 Ingredients used were ammonium nitrate, ammonium chloride and limestone fines of the grists indicated in Example 1 and were used in the same relative proportions. These ingredients were first mixed together and then granulated by a fusion process. The granules passed a 20 B. S. S. screen, and were thereafter mixed with the liquid nitric ester-nitrocellulose jelly as used in Example 1. When the ratio of the granules to the jelly was 93:7 and the packing density was 0.93, the corresponding velocity of detonation was about 1,500, and when the ratio was 95:5 and the packing density 0.92 the velocity of detonation was about 1,300. In each case the cartridges failed to give ignitions in gallery tests 1rzionducted as prescribed for the oflicial gallery ests.
• Low power explosive compositions comprising at least 30% by weight of the explosive of ammonium nitrate, a less proportion of detonating explosive sensitizer ingredient, an oxidizable ammonium salt selected from the group consisting of ammonium chloride, ammonium sulphate, and ammonium phosphate, and an insoluble metal carbonate, said oxidizable ammonium salt and metal carbonate being present in amounts sufiicient to provide two ammonium radicals and at least one carbonate radical for every three molecules of ammonium nitrate.

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Citations (9)

• 0
  • NL NL61258D patent/NL61258C/xx active
• 1945
  • 1945-11-15 US US628966A patent/US2481795A/en not_active Expired - Lifetime
  • 1945-12-24 FR FR919311D patent/FR919311A/fr not_active Expired

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