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

• This invention relates to new compositions of matter and in particular it relates to new explosive compositions of matter.
• Explosive compositions in the form of slurries and comprising oxidizing salts, fuel, sensitizers, and water, optionally together with conventional additives are known. Whilst such compositions have in the main been satisfactory for use as explosives it has been found that they suffer from the disadvantage that their sensitivity to detonation tends to be variable from batch to batch of production; in particular the sensitivity to detonation of such compositions tends to diminish from the original value during mixing, prolonged storage or after pumping into boreholes.
• alloys certain non-metallic elements or metals, particularly in finely divided form.
• various materials of high thermal energy including aluminium, silicon, ferrosilicon, ferrophosphorus, magnesium, titanium, boron and mixtures thereof for example mixtures of aluminium with ferrosilicon.
• These metals have been suggested for use both as fuels and as sensitizers. In general, these materials have been employed predominantly as fuels.
• these materials are in a very finely divided form, for example in the form of a powder passing a 300 mesh sieve or prepared so as to have a high surface area per unit weight such as up to 2.5 and as much as or more square metres per gram, certain of such metals act in the explosive composition as sensitizers to detonation as well as behaving as fuel materials.
• sensitizers As a typical example of metals in finely divided form there may be mentioned fine aluminium powder. Whilst these finely divided metals are eminently suitable as sensitizers it is known from the prior art that their effectiveness as sensitizers in certain aqueous explosive slurries is progressively reduced with time either whilst the composition is standing or whilst it is being mixed or pumped or otherwise sheared.
• Such slurry explosives tend to become less sensitive to detonation when exposed to water in a wet borehole. It has been suggested that such aqueous compositions containing very finely divided metal lose their sensitivity with time because more and more of the metal surface becomes wet. So as to reduce the wetting effect it has been suggested that the finely divided metals be treated with various coating or surface active matereials were for example paraffin, stearic acid, calcium stearate or a tallow amine. Whilst these materials were effective for a short period of time, they were ineffective over prolonged periods. In particular we have also observed that such hydrophobically treated metals incorporated in slurry explosive compositions become wetted when a conventional additive such as a guar gum is present.
• a conventional additive such as a guar gum
• a slurry explosive composition of matter comprising at least one oxygen releasing salt; water; and at least one fuel
• said composition of at least one detonation sensitizing material in divided form and comprising at least one metallic component selected from the group consisting of aluminium and alloys rich in I aluminium
• said detonation sensitizing material being characterized in that there is bonded to the surface of at least part of said metallic component at least one further material derived and selected from the group consisting of rosin, resin acids and derivatives thereof and wherein said further material constitutes from 0.01% to 0.2% w/w of said detonation sensitizing material.
• a detonation sensitizing material there may be mentioned the product obtained by the reaction of aluminium powder with sodium abietate which product has excellent water repelling properties.
• the amount of metallic detonation sensitizing material present in our compositions may vary over a wide range and will depend to some extent on the nature and proportions of other ingredients in the composition and on the desired degree of sensitivity to detonation of the composition. For many purposes satisfactory sensitivity to detonation may be achieved if the metallic detonation sensitizing material constitutes up to 10% w/w of the composition. However, amounts greater than these, for example up to say 15% or 20% may be used if desired.
• the degree of subdivision of the metallic detonation sensitizing material may vary over a wide range and particles ranging in size from coarse, for example when about 20% of the particles are retained on a 36 BS mesh sieve and about 50% of the particles are retained on a 60 BS mesh sieve, to fine, for example when substantially all the particles pass through a 350 B8 mesh sieve, are satisfactory.
• rosin we mean a solid resinous material that occurs naturally in the oleoresin of pine trees. It is a complex mixture of mainly resin acids and a small amount of nonacidic components. It may be modified from its natural state by chemical treatment such as hydrogenation, dehydrogenation dimerization or polymerization. Both the naturally occurring and modified rosin may be converted to carboxylic acid derivatives or salts of such derivatives.
• the resin acids referred to above have a typical molecular formula: 0.05300, and are cyclic compounds R-COOH wherein R is a group comprising a ring system-usually a three ring system-containing two double bonds. Typical of such resin acids is abietic acid.
• resin acids which may be mentioned include for example levopimaric acid, neoabietic acid, palustric acid, dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, primaric acid, isopimaric acid, 13" isopimaric acid, elliotinoic acid and sandaracopimaric acid.
• alkali metal or alkaline earth metal salts for example sodium or calcium abietate.
• the amount of rosin, resin acids or derivatives thereof in our compositions may be varied over a wide range. It will depend to some extent on the desired detonation sensitivity, and on the nature and state of subdivision of the metallic component to which the rosin, resin acid or derivatives thereof is attached. Thus we have found that suitable amounts of rosin, resin acids or derivatives thereof, expressed for convenience as abietic acid, present in our compositions and attached to a metallic component lie in the range from 0.0001 to 0.04 w/w of the composition.
• the oxygen releasing salts suitable for use in our compositions are of the conventional types used in slurry explosive compositions. Thus they may be, for example, inorganic nitrates, chlorates and perchlorates and mixtures thereof.
• the oxygen releasing salt material be chosen from the nitrates of the alkali and alkaline earth metals or ammonium and of these we prefer sodium nitrate and ammonium nitrate.
• the amount of oxygen releasing salt in our compositions is not narrowly critical; we have found that compositions containing amounts of oxygen releasing salts from 50% wlw to 90% w/w of the total composition are satisfactory and amounts from 65% wlw to 85% w/w are preferred.
• the particle size and shape of the oxygen releasing salt is not critical and is well known from the art of ammonium nitrate manufacture; powders and prilled particles are satisfactory.
• the proportion of waterin our compositions should be sufficient to dissolve at least part of the oxygen releasing inorganic salt and at least part of any water soluble fuel which may be present, and also be sufficient to hydrate at least part, preferably all of any thickening agent present.
• the amount of water present may constitute from wlw to 35% w/w of the total composition, but the amount present should not be in excess of the'explosive limit of the composition.
• the water be in the range from 5% w/w to 25% w/w of the total composition and more preferably be in the range from 12% w/w to 17% wlw of the total composition.
• the fuels employed in' the compositions of this invention can be, for example, self-explosive fuels, nonexplosive carbonaceous, non-metallic and metallic fuels or mixtures of the aforementioned types of fuels. They can be varied widely.
• selfexplosive fuels include one or more organic nitrates, nitrocompounds and nitramines such as trinitrotoluene, cyclotri (or tetra) methylenetri (or tetra) nitramine, tetryl, pentaerythritol tetranitrate, explosive grade nitrocellulose and nitrostarch.
• the self-explosive fuel can be for example in any of the well known flake, crystalline or pelleted forms. In general up to 35% and preferably from 10 to 30% by weight based on the weight of composition of selfexplosive fuel may be used.
• Suitable water soluble fuels are organic water soluble substances for example urea, carbohydrates such as sugars or molasses, water soluble alcohols or glycols, glues or mixtures of these.
• the proportion of water soluble fuel in our compositions is in the range from 0.8% w/w to 8% w/w of the total composition. Amounts from 4% w/w to 7% w/w of the total compositions are preferred.
• Suitable water insoluble or sparingly water soluble fuels may be chosen from inorganic materials for example sulphur, aluminium, silicon, ferrosilicon, ferrophosphorus, titanium, boron, mixtures thereof for example mixtures of aluminium with ferrosilicon, or organic materials for example finely divided charcoal, anthracite, gilsonite asphalt, cellulosic materials such as sawdust, or cereal products for example flours, dextrins or starches.
• the inorganic fuel is a metal it is preferably in granulated or powdered form ranging in particle size from coarse, for example retained on a 30 mesh sieve, to very fine for example passing a 325 mesh sieve.
• Such granulated or powdered metal may be in the form of discrete regular shaped particles, but metal powders wherein the metal is in the form of irregular shaped particles, or in flakes or in the form of aggregates of particles or flakes are also satisfactory.
• Preferred fuels are the metallic powders.
• the most preferred metallic fuel is aluminium.
• the proportion of water insoluble or sparingly water soluble non-metallic fuels in our compositions may suitably be in the range from 1% w/w to 10% w/w of the total composition and amounts from 4% w/w to 7% wlw of the total composition are preferred.
• the proportion of metallic water insoluble fuels when present in our compositions may be as high as 25% w/w and amounts in the range from 0.5% w/w to 20% w/w of the total compositions are preferred.
• additives may include for example thickening agents, such as guar gum or biopolymeric materials prepared from carbohydrates, in amounts ranging eg from 0 to 5 parts; cross-linking agents, for example zine chromate, in amounts ranging e.g. from 0 to 0.1 part, anti-foaming agents, for example ethyl hexanol, in amounts ranging e.g. from 0 to 0.1 part.
• additional sensitizers in the form of gas or a mixture of gases such as air may be added to our compositions.
• a gas such as nitrogen or carbon dioxide, may if desired be generated in the composition by known means.
• compositions are advantageous in comparison with slurry explosive compositions of the prior art since by means of the modifying reactant material in the form of rosin, resin acids, or derivatives thereof the range of aluminium powders suitable for use as a component of a sensitizing material has been extended in comparison with the aluminium powders used as sensitizing materials in the prior art.
• the so called atomized aluminium powders as components of sensitizing materials.
• such atomized aluminium powders have acted merely as fuels in prior art compositions and have hitherto been considered as being ineffective as sensitizing materials. Consequently the use of such atomized powders has provided cheaper explosive slurries, since they are less costly than the so called paint fine types of aluminium powders used previously.
• compositions of matter are useful in processes comprising a blasting operation and such compositions may be used in mining activities or the preparation of sites prior to the erection of buildings or machinery.
• EXAMPLE 1 For the purposes of comparison there was added to and blended with 98 parts of the stock material described above 2 parts of atomized aluminium powder 99% of which passed through a 350 BS mesh sieve. The resultant prior art slurry explosive composition was cartridged in cardboard tubes. It was found that the minimum amount of pentolite required to detonate a 3-inch diameter cartridge of the above composition at 75F was 140 grams.
• Example 2 For the purposes of comparison the general procedure of Example 1 was repeated but the atomized aluminium powder used in that Example was replaced by 2 parts of a metallic detonation sensitizing material consisting of the same atomized aluminium as used in Example 1 and which had been surface coated with 0.1% of its weight of sodium lauryl sulphate. It was found that the minimum amount of pentolite required to detonate a 3-inch diameter cartridge of the above prior art slurry explosive composition at 75F was 35 grams. 7
• EXAMPLE 3 A portion of the aluminium powder used in Example 1 was reacted with an aqueous solution of sodium abietate to provide a modified aluminium powder having water repellant properties and which had bonded to its surface a layer of material derived from the sodium abietate. The said layer constituted 0.1% of the said modified aluminium powder. There was added to and blended with 98 parts of the stock material described above 2 parts of the modified aluminium powder prepared above to provide a slurry explosive composition according to this invention. The composition was cartridged in cardboard tubes. it was found that the minimum amount of pentolite required to detonate a 2 inch diameter cartridge of the above composition at F was 25 grams.
• Example 4 For the purposes of comparison the general procedure of Example 1 was repeated but the atomized aluminium powder of that Example was replaced by 2 parts of the same atomized aluminium as used in Example 1 and which had been surface coated with 0.1% of sodium stearate. It was not possible to detonate a 4 inch diameter cartridge of the resultant prior art slurry explosive composition at 67F when 70 grams of pentolite was used as a detonating material.
• Example 5 The general procedure of Example 3 was repeated, but the atomized aluminium powder of that Example was replaced by a coarse atomized aluminium powder in which 18% of the particles were retained on a 36 BS mesh sieve; 50% of the particles were retained on a 60 BS mesh sieve; of the particles were retained on a BS mesh sieve and 99% of the particles were retained on a BS mesh sieve.
• the layer of material bonded to the surface of the aluminium powder and derived from the sodium abietate constituted 0.1% of the modified aluminium powder. It was found that the minimum amount of pentolite required to detonate a 4 inch diameter cartridge of the above composition according to our invention at 67F was 70 grams.
• EXAMPLE 6 For the purposes of comparison there was added to and blended with 900 pans of the second stock material described above 40 parts of a non-hydrophobic aluminium powder available under the Trade Name of Atomised Aluminium Powder ZOO/Dust and wherein all the particles passed a 150 BS mesh sieve; 3% of the panicles were retained on a 240 ES mesh sieve; and 25% of the particles were retained on a 300 BS mesh sieve; and 60 parts of a nonhydrophobic aluminium powder 99% of which passed through a 350 BS mesh sieve.
• the resultant prior art explosive slurry composition was cartridged in cardboard tubes. After storage for one day it was found that the minimum amount of pentolite required to detonate a 3 inch diameter cartridge of the above composition was 70 grams. A similar result was obtained after 2 days storage.
• Example 7 Example 8
• Example 9 Atomised Aluminium Powder ZOO/Dust 80 pans pans 40 parts
• EXAMPLES IOTO l2 INCLUSIVE The general procedure of Examples 7 to 9 inclusive was repeated but the modified aluminium powder used in those Examples was replaced by another modified aluminium powder prepared as follows:- To 100 parts an aqueous 0.05% solution of a material prepared by the saponification with sodium hydroxide of a fully hydrogenated rosin available commercially under the Trade Name of Foral AX" there was added 10 parts of a non-hydrophobic aluminium powder 99% of which passed through a 350 BS mesh sieve.
• the mixture was stirred for 10 minutes at 25C and the resultant solid product was separated from the reaction mixture by filtration and thereafter dried at room temperature for a period of 2 days.
• the resultant dried product was in the form of finely divided hydrophobic particles. 0.01 pan of the rosin was removed from the solution during the reaction period.
• the resultant explosive slurry explosive compositions were cartridged in cardboard tubes of 2 inches diameter and stored for the times as set out in Table 2. After this time the cartridges were detonated and the minimum amount of detonating material required to detonate the cartridges was determined. The results obtained are set out in Table 2.
• Example 13 The general procedure of Example I l was repeated except that the second stock material used in that Example was replaced by a similar stock material but wherein the I part of thiourea was replaced by 1 part of zinc chromate.
• the resultant cross linked explosive slurry composition in the form of a 2 inch diameter cartridge was detonated by 5 grams of pentolite after both 1 day and 24 days of storage.
• EXAMPLE 14 The general procedure of Example 13 was repeated but the modified aluminium powder of that Example was replaced by 40 parts of another modified aluminium powder prepared in a similar manner to that described in Examples to 12 inclusive except that the non-hydrophobic aluminium powder used as a starting material in those Examples was replaced by the non-hydrophobic aluminium powder referred to as Atomised Aluminium Powder 200/Dust" in Example 6.
• the cross linked explosive slurry so obtained in the form of a 2 inch diameter cartridge was detonated by 50 gm of pentolite after being stored for I day after manufacture. After 24 days of storage detonation was achieved using 80 gm of pentolite.
• Example 15 The general procedure of Example 5 was repeated but the modified aluminium of that Example was replaced by 10 parts of a modified aluminium sensitizer comprising the atomized aluminium powder of Example 5 having 0.16% of material derived from sodium abietate bonded to its surface. The resultant product in the form of a 4 inch cartridge was exploded successfully.
• EXAMPLE 16 The general procedure of Example 3 was repeated but the modified aluminium of that Example was replaced by a product from the reaction of an aluminium powder 99% of which passed a 350 mesh sieve with an aqueous solution of sodium abietate whereby there was obtained a modified aluminium 'powder having 0.012% of hydrophobic matter bonded to its surface.
• the modified aluminium was somewhat less hydrophobic than the modified aluminium used in Example 3, but when 5 parts thereof were added to and blended with 95 parts of first stock material referred to hereinbefore there was obtained an explosive slurry composition which was exploded successfully.
• a slurry explosive composition of matter comprising at least one oxygen releasing salt selected from the group consisting of ammonium nitrate, chlorate and perchlorate, alkali metal nitrates, chlorates and perchlorates, and alkaline earth metal nitrates, chlorates and perchlorates; water; and at least one fuel selected from the group consisting of water soluble fuels, water soluble or sparingly water soluble non metallic fuel and metallic water insoluble fuel, the combination with said composition of at least one detonation sensitizing material in divided form and comprising at least one metallic component selected from the group consisting of aluminium and alloys rich in aluminium said detonation sensitizing material the improvement wherein there is bonded to the surface of at least part of said metallic component at least one further material derived and selected from the group consisting of alkali metal salts of a resin acid, alkaline earth salts of a resin acid, hydrogenated rosin, dehydrogenated rosin, dimerized rosin and polymer
• said oxygen releasing salt is present in an amount from 50 to parts; said water is present in an amount from 5 to 25 parts; and said fuel is at least one fuel selected from the group consisting of water soluble fuel present in an amount from 0.8 to 8 parts, water insoluble or sparingly water soluble non metallic fuel present in an amount from 1 to 10 parts, and metallic water insoluble fuel present in an amount from 0.5 to 20 parts
• composition of matter according to claim 1 wherein the metallic component of said detonation sensitizing material comprises aluminium in divided form wherein up to 50% w/w of the particles therein are retained on a 60 BS mesh sieve.
• composition of matter according to claim 1 wherein the metallic component of said detonation sensitizing material comprises aluminium in divided form wherein not more than 5% w/w of the particles therein are retained on a 240 BS mesh sieve and up to 30% wlw of the particles therein are retained on a 300 BS mesh sieve.
• composition of matter according to claim 1 wherein the metallic component of said detonation sensitizing material comprises aluminium in divided form wherein at least 95% wlw of the particles therein are capable of passing through a 350 BS mesh sieve.
• composition of matter according to claim 1 wherein said bonded material is derived from an alkali metal or alkaline earth metal salt of a resin acid.
• composition of matter according to claim 1 wherein said bonded material is derived from sodium abietate.
• composition of matter according to claim 1 wherein said bonded material is derived from a modified rosin.
• composition according to claim 1 wherein said bonded material is derived from a saponified hydrogenated rosin.
• composition according to claim 1 wherein said bonded material is derived from abietic acid.

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• 1971
  • 1971-12-22 US US210654A patent/US3919013A/en not_active Expired - Lifetime
• 1972
  • 1972-07-12 AU AU57263/73A patent/AU472752B2/en not_active Expired
• 1973
  • 1973-06-28 GB GB3075573A patent/GB1396458A/en not_active Expired
  • 1973-07-09 PH PH14806A patent/PH10111A/en unknown
  • 1973-07-11 DE DE19732335317 patent/DE2335317A1/de active Pending
  • 1973-07-11 CA CA176,190A patent/CA1012360A/en not_active Expired
  • 1973-07-11 BE BE133376A patent/BE802219A/fr unknown
  • 1973-07-11 FR FR7325435A patent/FR2192082B1/fr not_active Expired
  • 1973-07-11 ES ES416794A patent/ES416794A1/es not_active Expired
  • 1973-07-11 OA OA54965A patent/OA04446A/fr unknown
  • 1973-07-11 ZA ZA00734664A patent/ZA734664B/xx unknown

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