Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B47/00—Compositions in which the components are separately stored until the moment of burning or explosion, e.g. "Sprengel"-type explosives; Suspensions of solid component in a normally non-explosive liquid phase, including a thickened aqueous phase
  • C06B47/14—Compositions in which the components are separately stored until the moment of burning or explosion, e.g. "Sprengel"-type explosives; Suspensions of solid component in a normally non-explosive liquid phase, including a thickened aqueous phase comprising a solid component and an aqueous phase
• • 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
  • Y10S149/114—Inorganic fuel

Definitions

• the present invention relates to a slurry explosive containing aluminum powder and having an improved specific gravity and an improved sensitivity.
• a slurry explosive containing ammonium nitrate, or ammonium nitrate and a nitrate of an alkali metal and/or an alkaline earth metal especially a slurry explosive containing ammonium nitrate and 2,4,6-trinitrotoluene (hereinafter referred to as TNT) or aluminum powder or a mixture thereof and water as the main ingredients is known as an effective industrial explosive, and has been satisfactorily used at sites such as hard rock or water springs, where an ammonium nitrate-fuel oil explosive cannot be employed.
• TNT 2,4,6-trinitrotoluene
• Such an explosive is absolutely safe in handling, and can easily be charged into a bore hole.
• Such an explosive has been charged by means of a forcing pump utilizing the slurry characteristic thereof.
• a slurry explosive has a higher explosion velocity and illustrates a better explosive performance in comparison with the well known ammonium nitrate-fuel oil explosive.
• such a slurry explosive is effective in boulder blasting, and crushing costs in succeeding steps are considerably reduced.
• such a slurry explosive is lower in transportation cost and boring cost, since it is higher in specific gravity than the ammonium nitrate-fuel oil explosive.
• such a slurry explosive is not only excellent in explosive performance but is also characterized by being safer because water is contained in the composition.
• ammonium nitrate TNT water ammonium nitrate-TNT-aluminum-water, ammonium nitrate-smokeless powder-water, ammonium nitratesmokeless powder-aluminum-water, ammonium nitrate-aluminum-water and ammonium nitrate-fuel-water.
• ammonium nitrate- TNT-water or ammonium nitrate-aluminum-water system is most effectively used.
• Aluminum used for the preparation of slurry explosives has been conventionally selected from the classes in a limited range, such as ball milling aluminum powder. Such aluminum powders are occasionally employed by coating the surface thereof with stearic acid, as described in the specification of US. Pat. No. 3,367,805. This is due because the aluminum powder must coexist with water in the slurry explosive. Consequently, this causes the cost of manufacturing slurry explosives to be high.
• such aluminum powder for example that manufactured by the ball milling method or the stamping method, has a very small bulk specific gravity, and therefore the specific gravity of a slurry explosive containing such an aluminum powder is often 1.1 to 1.2.
• Aluminum powder manufactured by the ball milling method or the stamping method is of very high sensitivity.
• a slurry explosive consisting of 72 percent by weight ammonium nitrate, 7 percent by weight aluminum powder manufactured by the ball milling method, 20 percent by weight water, and 1 percent by weight carboxymethyl cellulose (hereinafter referred to as CMC) is charged in a steel pipe (35 mm. inner diameter and 250 mm. in length) initiation takes place with only one No. 6 electric cap.
• CMC carboxymethyl cellulose
• a TNT-aluminum system slurry explosive solves the above problems of the TNT-slurry explosives.
• the TNT-aluminum system slurry explosive has the merit of the high sensitivity of aluminum powder manufactured by the ball milling method or the stamping method and the high specific gravity and high explosive power of TNT, and offers an extremely high performance.
• this explosive is high in cost and also is very poor from a safety viewpoint.
• this explosive has a problem with production control because two kinds of very different dangerous materials, such as TNT and aluminum powder are required in its manufacture.
• an improved explosive is obtained when the aluminum powder consists of aluminum powder (a) which is manufactured by the ball milling method or the stamping method, the particle size of which is 30 mesh (JIS sieve) or below, and aluminum powder (b) having no leafing property which is manufactured by the atomizing method or the graining method, the particle size of which is 30 mesh (JIS sieve) or below, the mixing ratio by weight of the aluminum powder (a) and the aluminum powder (b) being about 50 to 20 50 to 80.
• One object of the invention is to provide an aluminum-containing slurry explosive having a specific gravity comparable to that of the TNT system slurry explosive.
• a further object is to provide a safe explosive with an initiating sensitivity which can be freely controlled.
• Another object is to provide an explosive which is highly economical.
• a slurry explosive containing as the main ingredients: (1 40 to percent, by weight, of ammonium nitrate or a mixture of ammonium nitrate and an alkali metal nitrate or a mixture of ammonium nitrate, and an alkaline earth metal nitrate or a mixture of ammonium nitrate, an alkali metal nitrate and alkaline earth metal nitrate; (2) 5 to 20 percent by weight of aluminum powder consisting of aluminum powder (a) which is manufactured by the ball milling method or the stamping method Aluminum" 445, 22 (1967)), the particle size of which is 30 mesh (JIS sieve) or below, and aluminum powder (b) having no leafing property which is manufactured by the atomizing method or the graining method and the particle size of which is 30 mesh (JIS sieve) or below, the mixing ratio, by weight, of
• the slurry explosive of the present invention may contain one or more materials such as TNT, smokeless powder, carbonaceous fuels including carbon powder and fuel oils, etc., and/or a paste for suspension stability, in addition to the above main ingredients.
• aluminum powder (a) manufactured by the ball milling method or the stamping method has a lcuflng property, while the latter does not.
• aluminum powder (a) is lower in apparent specific gravity and higher in specific surface area and sensitivity in comparison with aluminum powder (b). Therefore, when blending such aluminum powders in various ratios and incorporating the blended aluminum powders into the slurry explosive, a slurry explosive having the desired specific gravity, sensitivity and explosion velocity is obtained.
• the aluminum system slurry explosive containing ammonium nitrate, aluminum powder manufactured by the stamping method, aluminum powder manufactured by the atomizing method and water as its main ingredients is most preferably employed because of the facts that its specific gravity is good, its explosion velocity is high, its preparation is easy, and it is safe to use.
• the particle size of the aluminum incorporated into the slurry explosive is related to the viscosity of the slurry explosive. That is, in order to suspend aluminum powder having a large particle size, a large amount of paste is required, and therefore, a slurry explosive containing such aluminum powder suffers from deteriorated flowability and lowered sensitivity.
• monium nitrate-aluminum-water system having incorporated therewith aluminum powder manufactured by the stamping method and aluminum powder manufactured by the atomizing method, in various ratios, are as shown in Table 2.
• a slurry explosive containing 7 percent by weight of atomizing method aluminum powder exploded incompletely in a 35 mm. inner Composition of slurry explosive, percent by weight Aluminum Aluminum powder by powder by Filling atomizing stamping Ammonium Guardensity, method method nitrate Water gum CMC g./cm.
• the content of aluminum powder manufactured by the atomizing method is preferably above 7 perdiameter iron pipe, but exploded completely in 80 mm. thereof.
• the explosive containing stamping method aluminum powder was recognized to completely explode in 35 mm., even if its aluminum powder content was 5 percent by weight.
• minum (b) in the weight ratio of 2:7, or the like may be effectively employed in view of specific gravity, sensitivity, explosion velocity and safety in handling.
• the present invention will be illustrated with the following examples, which are, however, not to limit the scope of the present invention.
• the explosion velocity of the slurry explosive having the above composition was 5570 m/sec.
• EXAMPLE 1 The initiating sensitivity and explosion velocity of a slurry EXAMPLE 4 explosive containing 7 percent by weight of aluminum powder 5 (average particle size 44 manufactured by the atomizing method and 0 to 3 percent by weight of aluminum powder (by welsh) (average particle size 74 4) manufactured by the stamping g ifia g g g method and having the compositions shown in Table 4 were Aluminum prepared by the ball milling measured. The results are shown in Table 5.
• method g Particle Size) 1 3 TABLE 4 Composition of slurry explosive (percent, by weight) Aluminum by atom- Aluminum Ainmo- Antimonyl izing by stamping nium potassium Sample method method nitrate Water Guaigum Borax tartai'ate 7 0 72. 5 0. 3 O. l O. 7 1 7l. 5 20 0. 3 0. l 0. l 7 2 70. 5 20 0. 3 0. 1 0. 1 7 3 69. 5 2O 0. 3 0. 1 0. l
• TAB LE 5 Aluminum prepared by the atomizing method Initiation by it blasting cap using Initiation by a sg Pamela Sue) 3 (.etryl as a booster blasting cap only Hexamethylene ten e 6 Explosion Explosion cuafgum Filling velocity Filling velocity Antimonyl potassium tartarate 0.1 Sample Tetryl (g). density (m/sec) density (m./sec.)
• the slurry explosive composition having the above composition had a 1.29 filling density and a 4,700 m/sec. explosion velocity. In this case, initiation by a blasting cap was possible.
• CMC Q9 ry explosive further contains a member selected from the Octadecyltrimethyl ammonium chloride 0 1 group consisting of 2,4,6-trinitrotoluene, smokeless powder,
• a slurry explosive according to claim 1 wherein aluminum (a) is manufactured by the stamping method and aluminum (b) is manufactured by the atomizing method, and the slurry contains above 7 percent by weight of aluminum (b) but not above 15 percent by weight of aluminum (a).
• a sluny explosive according to claim 1 containing 40 to 80 percent by weight of ammonium nitrate.
• a slurry explosive according to claim 1 containing 40 to 80 percent by weight of a mixture of ammonium nitrate and an alkali metal nitrate.
• a slurry explosive according to claim 1 containing 40 to 80 percent by weight of a mixture of ammonium nitrate, an alkali metal nitrate and an alkaline earth metal nitrate.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Powder Metallurgy (AREA)

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Citations (5)

• 1969
  • 1969-10-17 ZA ZA697340*A patent/ZA697340B/xx unknown
  • 1969-10-23 GB GB1265718D patent/GB1265718A/en not_active Expired
  • 1969-10-24 US US869324A patent/US3664897A/en not_active Expired - Lifetime

Patent Citations (5)

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