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

Definitions

• This invention relates to an improved blasting explosive of the kind known as slurried explosive wherein a water- .soluble oxidising salt and fuel are suspended in an aqueous medium containing as a sensitizing ingredient, a liquid non-explosive organic nitrate, i.e., isopropyl nitrate or amyl nitrate.
• Slurried explosives for use in large diameter shotholes need not generally contain a self-explosive ingredient, but for slurried explosives having a specific gravity more than 1.3 for use in narrower shotholes it is usual, in order to avoid propagation failures, to include in the composition a self-explosive sensitising ingredient, for example TNT, PETN, cyclotrimethylenetrinitramine or nitroglycerine.
• a self-explosive sensitising ingredient for example TNT, PETN, cyclotrimethylenetrinitramine or nitroglycerine.
• a slurried blasting explosive as hereinbefore defined contains, as a sensitising ingredient, a liquid non-explosive organic nitrate.
• Preferred organic nitrates include isopropyl nitrate and amyl nitrate.
• the inclusion of these organic nitrates reduces the degree of aeration in the mixing of the composition, thereby enabling compositions of higher density to be prepared.
• the organic nitrates also tend to prevent the slurried explosives sticking to plastic containers. Slurried explosives in accordance with the invention may readily be prepared which will propagate in narrow shotholes 4) even at specific gravities greater than 1.3.
• the slurried explosive of the invention comprises 2 to 25% by weight of the liquid organic nitrate.
• the explosive composition preferably comprises, as oxidising salt, nitrate of ammonia, sodium, barium, potassium or calcium or a mixture of such nitrates.
• the composition comprises a mixture of ammonium nitrate and sodium nitrate containing at least 50% by Weight of ammonium nitrate.
• the fuel conveniently comprises carbon, fuel oil, carbohydrate, for example sugar, metal or metalloid, for example aluminium, magnesium, boron or silicon, water-soluble lignosulphonate or mixtures of these fuels.
• a thickening agent for example a water-soluble polysaccharide such as guar gum to thicken the water, or nitrocellulose 3,681,156 Patented Aug. 1, 1972 to thicken the organic nitrate.
• nitrocellulose When nitrocellulose is pres cut its rate of gelation may be increased by incorporating ethyl alcohol into the composition.
• the explosive may, if desired, comprise a cross-linking agent, for example zinc chromate or sodium borate, to crosslink the polysaccharide.
• a cross-linking agent for example zinc chromate or sodium borate
• the preferred slurried blasting explosive of the invention comprises (by weight) 50-85% ammonium nitrate, up to 15% sodium nitrate, up to 15 aluminium, up to 5% non-metallic fuel, 0.2-2.0% guar gum, 5-25% water and 225 isopropyl nitrate or amyl nitrate.
• the solid ingredients were first mixed and the liquids were then added and stirred into the mixture except that in Examples 6 and 7 the isopropyl nitrate and alcohol were first thickened with the nitrocellulose and the thickened mixture added to a mixture of the other ingredients.
• the velocity of detonation when confined was determined on a charge of explosive filling a mild steep pipe 1 /2" diameter x wall thickness or 3" diameter x 4" wall thickness detonated by a 30 g. Pentolite (50/50 TNT/PETN) primer.
• the velocity of detonation when unconfined was determined on a charge of explosive filling a 3%" diameter tube of polyethylene film detonated by a 225 g. Pentolite primer.
• the specific gravity of a slurried explosive of the same composition as Example 1 except that the isopropyl nitrate was replaced by sugar was 1.20.
• a slurried blasting explosive composition wherein a water-soluble inorganic oxidizer salt and a fuel are suspended in an aqueous medium containing as a sensitizing ingredient, a liquid non-explosive alkyl nitrate of from 3-5 carbons.
• nitrate is selected from the group consisting of isopropyl nitrate and amyl nitrate.
• An explosive as claimed in claim 1 comprising 2 to 25% by weight of said liquid organic nitrate.
• oxidizer salt is selected from the group consisting of ammonium nitrate, sodium nitrate, barium nitrate, potassium nitrate, calcium nitrate, and mixtures thereof.
• An explosive as claimed in claim 1 wherein the oxidizer salt is a mixture of ammonium nitrate and sodium nitrate containing at least 50% by weight of ammonium nitrate.
• An explosive as claimed in claim 1 wherein said fuel is selected from the group consisting of carbon, fuel oil, carbohydrate, metal, metalloid, water-soluble lignosulphon'ate and mixtures of these fuels.
• An explosive as claimed in claim 1 comprising a thickening agent.
• An explosive as claimed in claim 8 wherein the thickening agent comprises Water-soluble polysaccharide.
• An explosive as claimed in claim 9 comprising a cross-linking agent to cross-link the polysaccharide.
• An explosive as claimed in claim 10 wherein the cross-linking agent comprises zinc chromate or sodium borate.
• An explosive as claimed in claim 8 comprising as thickening agent, nitrocellulose.
• An explosive as claimed in claim 13 comprising ethyl alcohol to increase the rate of gelation of the nitrocellulose.
• a slurried blasting explosive as claimed in claim 1 comprising (by weight) 50 to 85% ammonium nitrate, up to 15% sodium nitrate, up to 15% aluminium, up to 5% non-metallic fuel, 0.2 to 2.0% guar gum, 5 to 25% of water and 2 to 25% isopropyl nitrate or amyl nitrate.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Air Bags (AREA)
• Drilling And Exploitation, And Mining Machines And Methods (AREA)
• Lubricants (AREA)
• Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10119164

Family Applications (1)

Country Status (13)

Cited By (2)

Family Cites Families (4)

• 1968
  • 1968-04-22 GB GB08831/68A patent/GB1180677A/en not_active Expired
• 1969
  • 1969-04-09 IE IE468/69A patent/IE33043B1/xx unknown
  • 1969-04-10 NO NO691469A patent/NO118534B/no unknown
  • 1969-04-14 BE BE731490D patent/BE731490A/xx not_active IP Right Cessation
  • 1969-04-16 DE DE19691919395 patent/DE1919395B2/de active Granted
  • 1969-04-17 ZM ZM53/69A patent/ZM5369A1/xx unknown
  • 1969-04-21 CH CH601069A patent/CH515196A/de not_active IP Right Cessation
  • 1969-04-22 BR BR208240/69A patent/BR6908240D0/pt unknown
  • 1969-04-22 ES ES366311A patent/ES366311A1/es not_active Expired
  • 1969-04-22 FR FR6912616A patent/FR2006705A1/fr not_active Withdrawn
  • 1969-04-22 OA OA53590A patent/OA03045A/fr unknown
• 1970
  • 1970-02-10 US US9122A patent/US3681156A/en not_active Expired - Lifetime
  • 1970-12-31 MY MY1970157A patent/MY7000157A/xx unknown

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