Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
• • 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
  • C06B31/30—Compositions containing an inorganic nitrogen-oxygen salt the salt being ammonium nitrate with vegetable matter; with resin; with rubber
• • 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

• ammonium nitrate which is-used is of the usual grist size and usually cannotfbe made'to explode in cartridges of the" general: nature and size re l of the aforesaid howeyer thatt a mixtureof ammosize as ordinarily used in the manuquired to attain explosive compositions.
• niuminitrate of grist facture of explosive density, as'for example balsa meal, cork dust and bagasse.
• explosive compositions of unusually low bulk density tend to become compacted during transport to a higher density withan adverse elfect' on their sensitiveness a i iati n a pmpa
• explosive compositions have been proposed for coal-mining which contain aluminium as an ingredient, as a result of increasingly stringent requirements in recent years in respect of freedom from danger in igniting methane, including for instance the introduction of ofiicial Gallery tests, no explosive composition containing aluminium as an ingredient has appeared for several years in the olficial list of explosives permitted for use in coal-mines for exampleby H. M. Home Office.
• the object of the present invention is to provide explosive compositions for use in gassy or bomby mines which are free from self-explosive ingredients and have a satisfactory sensitiveness to initiation and capacity for propagation and bulk densities in a range high enough to be maintained during transport and a greater strength than any that have hitherto been found safe enough for use in gassy or fiery mines.
• An explosive composition according to the invention comprises ammonium nitrate of particle size such that substantially all of it passes a 120 B. S. S. sieve, aluminium particles such that at least a part is paint-fine, vegetable tissue material, and at least one flame-quenching ingredient, and has a bulk density not less than 0.85 g./cc. and not greater than 1.1 gJ/cc. and is substantially oxygen balanced.
• the power of the explosive compositions of the invencompositions and aluminium powder i can be caused toexplode by means of a commercial detodiatom-if the'densityof the mixture is suitably diminished the inclusion therein of dry vegetable tissue.
• These yegetabletissue materials are specially eifective in facilitat inginitiation when they are of intrinsically lowbulk aluminium particles,
• tion should preferably be less than 74% blasting gelatine.
• organic ingredients for instance orthonitro toluol.
• flame-quenching ingredients are sodium chloride, sodium sulphate' and china clay. If sodium chloride 'is the flame-quenching ingredient the quantity present should be at least 8% and preferably not more than 25%. n
• the ammonium nitrate in the compositions of the invention. is of particlesize such that not less than 60% passes a No. 240 B. S; S. sieve, not less than passes a No. 170 B. S. S. sieve and substantially all, i. e, at least 98%, passes a No. B. S. S. siev It is also preferred thatthe total amount of aluminium in the composition be not less than 1%. and not more than 25% byxweight and that not less than 0.5% and not more than 1% of the aluminium present based on the'weight of the explosive composition be paint-fine aluminium.
• composition of the invention is satisfacexplosive compositions of the same percentage composition and power, the improvement is still insuificient to enable the whole of the oxidisablecontent of the explosive composition to consist of aluminium.
• thesensitising effect on ammonium nitrate of paint-fine aluminium is higher than that of granular aluminium the tendency of paint-fine aluminium to ignite methane-air mixtures is higher than that of granular aluminium and so the percentageof paint-fine aluminium that may be present in an explosive composition is even more severely limited than that of granular aluminium. Therefore, to achieve the desired sensitiveness to initiation and propagation of an explosive composition comprising ammonium nitrate in finely divided form and at least part of which is paint-fine, it.
• oxidisable ingredients are essential to include at least a portion of the remainder of the oxidisable ingredients to make thecomposition oxy'genjfbal'anced in the form of vegetable tissue material.
• Such material has the efiect furthermore of reducing the density of the composition more thanordinary oxidisable than 1.1 g./cc; if satisfactory sensitiveness to initiation and propagation is to be achieved. On the other hand it is undesirable that the density should be lower than 0.85 g./cc.
• examples of vegetable material suitable for use in the compositions of the invention are woodfiour, which has a density of about 0.4 g./cc., or lower density materials as for instance balsa meal, ground cork or bagasse.
• Ammonium nitrate as heretofore employed in explosives suitable for fiery or gassy coal-mines consists of crystal clusters or crystals of such size as to be substantially retained on a No. B. S. S. sieve and is inefiective forthe present invention tween 0.85 and 1.1 g./cc. mixtures of the same percentage compositions' containing such ammonium nitrate in place of the fine ammonium nitrate used in the compositions of the present invention are insensitive to commercial detonators and require the use of abooster the employment of whichis not permitted in, commercial coal-mining practice. 7
• compositions Nos. 1 to Sand compared with compositions Nos. 6 to 9 not in accordance with the invention in the following table.
• Ammonium nitrate of the usual commercial size i. e. one wherein only 20% passes a No. 120 B. S. S. sieve and only 75% passes a No. 60 B. S. S. sieve when used to make the explosive compositions indicated in the following table produce explosive compositions of such reduced sensitiveness that they fail to fire when formed into cartridges of the ordinary commercial size for use in bore holes in mines when any commercial detonator is used.
• cartridges are tested in accordpasses a No. 240 B. S. S. sieve, not less than 80% thereof passes a No. 170 B. S. S. sieve and substantially all thereof passes a No. 120B. S. S. sieve, from 1% to 2.5% of aluminum particles by weight of total composition wherein 0.5% to 1% of said particles by weight of total composition are of a pigment powder fineness, vegetable tissue material and at least one flame-quenching ingredient, and having a bulk density not less than 0.85 gram per cc. and not greater than 1.1 grams per cc. and being substantially oxygen balanced.
• An explosive composition as claimed in claim 1 which includes organic ingredients.
• An explosive composition as claimed in claim 1 wherein said flame-quenching ingredient is selected from the group consisting of sodium chloride, sodium sulphate and china clay.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Paints Or Removers (AREA)
• Fireproofing Substances (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10916101

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (6)

• 0
  • NL NL95896D patent/NL95896C/xx active
  • BE BE537650D patent/BE537650A/xx unknown
  • NL NL195933D patent/NL195933A/xx unknown
• 1955
  • 1955-04-08 US US500268A patent/US2829958A/en not_active Expired - Lifetime

Patent Citations (6)

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