Classifications

• • 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
  • C06B31/32—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound
  • C06B31/38—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound the nitrated compound being an aromatic
• • 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
• • 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
  • C06B31/32—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound
  • C06B31/38—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound the nitrated compound being an aromatic
  • C06B31/42—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with a nitrated organic compound the nitrated compound being an aromatic with other explosive or thermic 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

Definitions

• the present invention relates to an improvement in the production of safety ammonium nitrate blasting explosive powders such as are used in fiery or dusty mines and of the kind wherein. the sensitizing explosive ingredient is trinitrotoluene and the flame quenching ingredient comprises sodium chloride.
• the object of the present invention is to pro vide ammonium nitrate blasting explosives of the kind containing trinitrotoluene and sodium chloride which will have improved safety.
• asafety ammonium nitrate blasting explosive powder of the kind comprising ditions in a gallery test explosives according to the invention containing this amount of fine sodium chloride give better results than those containing no fines at:all, and are equally satisfactory acannon I, V, I
• safety explosive compositions consisting of a mixture of trinitrotoluene, ammoniumv nitrate and sodium chloride not to give olf poisonous fumes on initiation, that these compositions should have a calculated oxygen balance between 0.5 and +3 gms./ gms. of the composition.
• V j It is also often desirable to include in such compositions up to 4.5% of fibre in order to lower the bulk-density of the composition and to restore oxygen balance in explosives where the trinitrotoluene content is reduced to give enhanced safety From the stipulated oxygen of 0.5 to +3 gms. oxygen per 100 gms.
• the object of the present invention is to provide ammonium nitrate blasting explosives of. the kind containing trinitrotoluene and at least 35% sodium chloride which will have a velocity of detonation of at least 2,300 metres/ second and not more than 2,900 metres/second.
• Said ammonium nitrate blasting explosives which have a velocity of detonation less than 2,300 metres/second are less sensitive than is usually desirable for commercial purposes, while those which have a velocity of detonation greater than 2,900 metres/second have an adverse efiect on the suspended gallery test.
• a safety ammonium nitrate blasting explosive powder of the kind comprising trinitrotoluene and sodium chloride wherein the ammonium nitrate and the trinitrotoluene consist of fine particles in intimate admixture is characterized in that the amount of sodium chloride is at least 35% by weight on the explosive powder and in that such portion of the sodium chloride is retainable on a 120 B. S. S. sieve that the explosive powder has a velocity of at least 2,300 metres/second and not more than 2,900 metres/ second.
• composition containing 35% sodium chloride it is desirable to have at least 10% of sodium chloride on the explosive powder retainable on said sieve; and for a composition containing 40% sodium chloride it is desirable to have at least 17.5% of sodium chloride on the explosive retainable on said sieve.
• sodium nitrate is included less than 35% sodium chloride may give the desired degree of safety.
• the grist is such that all of the sodium chloride passesa 16 B. S. S, sieve in order to prevent segregation in transport.
• sodium nitrate and if desired also non-explosive solids in small proportions to give a satisfactory oxygen balance may also be included, these resulting explosives having satisfactory initiation and propagation sensitiveness and having better safety characteristics than any of the known unsheathed ammonium nitrate, trinitrotoluene, sodium chloride explosives.
• the whole amount of the sodium chloride present in the explosive composition may be of a grist too coarse to pass a 120 B. S. S. sieve, it is preferred that at least of the sodium chloride in the composition should be of a finer grist since under freely suspended firing conditions in a gallery test explosives according to the invention containing this amount of fine sodium chloride give better results than those containing no fines at all, and are equally satisfactory in the test in which they are fired from the cannon.
• a process for the production of a safety ammonium nitrate blasting explosive powder according to the present invention comprises grinding together trinitrotoluene and ammonium nitrate in known manner and thereafter lightly mixing into the milled mixture thus produced.
• sodium chloride at least a'portion of which is retainable on a 120 B. S. S. sieve.
• the trinitrotoluene and the ammonium nitrate may be first ground in known manner, for example in an edge runner mill in the absence of sodium chloride and thereafter the sodium chloride, which may be wholly or partly of grist too coarseto pass a 120 B. S. S.
• the sieve may then be lightly mixed with the milled mixture without further grinding, for instance by transferring the said mixture to an Atlas (registered trademark) mixer and working in the sodium chloride after the fashion employed in incorporating the ingredients of explosives containing liquid explosive nitric esters, or alternatively if an edge runner mill has been used for milling the ammonium nitrate and trinitrotoluene by working in the salt with the plows alone after raising the rolls clear of the mixture.
• Atlas registered trademark
• the blasting explosives according to the invention retain their sensitiveness, i. e. their firing properties for a period of at least 6 months.
• a positive sign indicates that the gas tests (suspended test and gun test) have been passed with respect to safety
• a negative sign indicates that the gas test'has not been passed with respect to safety.
• Example I In an edge runner mill set for close grinding there are ground together 11.9 parts flake trinitrotoluene 'and 53.1 parts ammonium nitrate having a fine surface deposit of the ammonium salt of trisulphonated pararosaniline amounting to 0.1% of its weight, the grinding being continued for minutes by which time substantially the whole mixture is fine enough to pass a 150. B. S. S. sieve. Further grinding has no beneficial eflfects on its sensitiveness. After the grinding is stopped the wheels are raised free of the mixture, into which there are worked by means of the plows 35 parts sodium chloride having a grist size so that all of it passes a 60 B. S. S. sieve and only 58% passes a 120 B. S. S. sieve.
• the resulting explosive has a velocity of detonation of 2,400 metres/second, is sensitive to a No. 3 commercial fulminate detonator and in the form of a 1.25 inch cartridge 3 inches long communicates detonation to a similar spaced 1 inch end to end from it.
• Its power is 43% of that of blasting gelatine and it has a density of 1.15 gms./ml. at 20 lbs/sq. in. 6 ozs. when fired freely suspended in a gallery test fail to ignite ,a 9% by volume methane-air mixture.
• a explosive of a similar composition but containing 35% sodium chloride in a finely divided form has a velocity of detonation of 2100 metres/second, is not sensitive to a No. 3 commercial fulminate detonator, and in the form of a 1.25 inch cartridge 3 inches long, communicates detonation to a similar cartridge spaced 0.5 inch end to end from it. 5 ozs. when fired freely suspended in the gallery test fail to ignite a 9% by volume methaneair mixture.
• Example 2 The wheels of the mill are then raised free of the mixture
• the resulting explosive has a velocity of detonation of 2600 metres/second, is sensitive to a No. 3 commercial 1 fulminate detonator, and in the form of a 1.25 inch diam eter cartridge 3 inches long, communicates detonation to a similar cartridge spaced 1 inch end to end from it.
• Its power is 41% of that of blasting gelatine and it has a density of 1.15 gms./ml. at 20 lbs/sq. in. 5 ozs. when fired freely suspended in a gallery test fail to ignite a 9% i I by volume methane-air mixture.
• Example 3 11 parts of trinitrotoluene are milled with'llparts of ammonium nitrate for 10 minutes as in Example 2.; 38 parts ammonium nitrate are added and the mixture milled for a further 20 minutes: The wheels of the mill are raised free of the mixture and. 40 parts sodium. chloride having a grist size so that all of it passes a 60 B. S. S. sieve and-is retained on a B. S. S. sieve are worked into the mixture by means of the plows.
• the resulting explosive has a velocity of detonation of 2700 metres/second, is sensitive to a No. 3 commercial fulminate detonator, and in the form of a 1.25 inch diameter cartridge 3 inches long, communicates detonation to a similar cartridge 1.5 inches end to end from it.
• Its power is 39% blasting gelatine and it has a density 'of 1.15 gms./ml. at 20 lbs/sq. in. 502s. when fired freely suspended in a gallery test failed to ignite a 9% by volume methane-air mixture.
• An explosive of similar composition containing 40% sodium chloride in a finely milled state fails to propagate.
• Example 4 11 parts of trinitrotoluene and 11 parts of ammonium nitrate are milled for 10 minutes. 38 parts ammonium nitrate and 20 parts sodium chloride are added andthe mixture milled for a further 20 minutes. 20 parts sodium chloride having a grist size so that all of it passes a 16 B. S. S. sieve and is retained on a 60 B. S. S. sieve, are added and milling continued for a further 3 minutes by which time mixing is completed and little comminution of the sodium chloride has taken place.
• the resulting explosive has a velocity of detonation of 2400 metres/second, is sensitive to a No. 3 commercial fulminate detouator and in the form of a 1.25 inch diameter cartridge 3 inches long communicates detonation to a similar cartridge spaced 1 inch end to end from it.
• Its power is 39% blasting gelatine and it has a density of 1.15 gms./ml. at 20 lbs./sq. in. 6 ozs. when'fired freely suspended in the gallery test fail to ignite a 9% by volume methane-air mixture.
• An explosive of similar composition containing 40% sodium chloride in finely divided form fails to propagate.
• Example 5 5.6 parts of trinitrotoluene and 5.6 parts ammonium nitrate are milled for 10 minutes in an edge runner mill. 48.9 parts ammonium nitrate and 16.4 parts sodium chloride are added and milled for a further 20 ininutes.-
• the resulting explosive has a velocity of detonation of.
• S. S. sieze and not more than by weightof 'the sodium chloride passes a B; S. S.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Air Bags (AREA)
• Glass Compositions (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
• Drilling And Exploitation, And Mining Machines And Methods (AREA)

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Cited By (6)

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Citations (1)

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• 0
  • BE BE524351D patent/BE524351A/xx unknown
• 1952
  • 1952-11-19 GB GB29198/52A patent/GB743710A/en not_active Expired
• 1953
  • 1953-11-02 US US389887A patent/US2839374A/en not_active Expired - Lifetime
  • 1953-11-10 FR FR1092612D patent/FR1092612A/fr not_active Expired
  • 1953-11-13 DE DEI7896A patent/DE945011C/de not_active Expired

Patent Citations (1)

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