US3919013A

US3919013A - Use of graphite fibers to augment propellant burning rate

Info

Publication number: US3919013A
Application number: US210654A
Authority: US
Inventors: Richard Winer
Original assignee: Hercules LLC
Current assignee: Hercules LLC
Priority date: 1972-07-12
Filing date: 1971-12-22
Publication date: 1975-11-11
Anticipated expiration: 1992-11-11
Also published as: DE2335317A1; AU472752B2; BE802219A; PH10111A; ES416794A1; OA04446A; CA1012360A; FR2192082B1; AU5726373A; FR2192082A1; ZA734664B; GB1396458A

Abstract

Solid propellant compositions having graphite fibers dispersed throughout the propellant are provided. The graphite fibers augment the burning rate of the solid propellant.

Description

United States Patent 1 Fox, et a].

[ Nov. 11, 1975 [54] SLURRY EXPLOSIVE COMPOSITION [75] Inventor: Richard Fox, Rosanna; David Gilbert Hay, Balaclava, both of Victoria, Australia [73] Assignee: ICI Australia Limited,

Melbourne, Victoria, Australia [22] Filed: June 25, 1973 [2]] Appl. No.: 372,932

UNITED STATES PATENTS 5/1966 Clay et a1. l49/6 1/1967 Chrisp 149/6 Primary Examiner- Leland A. Sebastian Attorney, Agent, or Firm-Cushman, Darby & Cushman EXEMPLARY CLAIM 1. in 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 nonmetallic 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 polymerized rosin and wherein said further material constitutes from 0.01 to 0.2% w/w of said detonation sensitizing material.

llClaims, No Drawings SLURRY EXPLOSIVE COMPOSITION 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.

Amongst the materials which have been proposed in the prior art for use in slurry explosives are alloys, certain non-metallic elements or metals, particularly in finely divided form. To contribute energy to the explosive the prior art has proposed the use of 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. When however 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. 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. It is also known that 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.

OBJECT OF THE INVENTION It is an object of the present invention to improve the sensitivity to detonation of slurry explosive compositions, and in particular to reduce the rate at which such compositions become desensitized on storage. It is a further object of the present invention to provide slurry explosive compositions which have an enhanced water resistance over compositions of the prior art.

In our United States Pat. No. 3,875,135, we have described new compositions of matter comprising the reaction product of rosin, resin acids or derivatives thereof with certain metals or alloys. We have now found that certain of the new compositions described therein may be incorporated advantageously in slurry explosive compositions of matter to provide explosive compositions of matter which have enhanced sensitivity when compared with prior art slurry explosive compositions.

Accordingly we provide in a slurry explosive composition of matter comprising at least one oxygen releasing salt; water; and at least one 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 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. As an example of such 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.

By 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. Other 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. From amongst typical salts, of the carboxylic acids there may be mentioned 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. We prefer that 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. Suitably 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. We prefer that 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.

When referring to fuels or fuel materials throughout this specification we mean substances which are stable in our explosive compositions, that is prior to detonation, during preparation and storage the substance is chemically inert to the system. The said substances must be conbustible and their physical nature should be such that they may be incorporated in our compositions in a manner so as to be uniformly distributed throughout the compositions. Such fuels are well known in the art and they may be organic or inorganic and may also be derived from animals and plants.

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. Examples of 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. Suitably 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. When 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.

Where desirable, it is convenient to add to the slurry explosive compositions according to our invention, in amounts expressed as parts by weight per parts by weight of the final mixture, other conventional additives used in slurry explosives. Such 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. When desired, additional sensitizers in the form of gas or a mixture of gases such as air may be added to our compositions. Thus it may be added in the form of injected or stirred in air or gas or it may be added as air or gas encapsulated in or attached to the surface of particulate material. Alternatively a gas, such as nitrogen or carbon dioxide, may if desired be generated in the composition by known means.

Our 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. Thus for example it is now possible to use the so called atomized aluminium powders as components of sensitizing materials. As far as we are aware 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.

Our 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.

Accordingly we provide in a process of blasting wherein a slurry explosive composition of matter is loaded into a borehole and detonated therein the improvement which comprises the use of explosive compositions of matter according to our invention as the slurry explosive composition.

Our invention is now illustrated by, but in no way limited to, the following examples wherein all parts and percentages are expressed on a weight basis unless otherwise specified. Examples l, 2, 4 and 6 are included for the purposes of comparison and are not within our invention.

A composition according to the prior art was prepared by blending by conventional means the ingredients set out below in the proportion as set out below:

PMS

Powdered ammonium nitrate 60.6 Sodium nitrate 13 Water 13 Coarse aluminium powder 2 Sugar 5 Gilsonite 2 Sulphur 2 Guar gum 0.4

The above blend of materials was used as a first stock material in Examples 1 to 5 inclusive, i5, 16 and [7.

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.

A further composition according to the prior art was prepared by blending by conventional means the ingredients set out below in the proportion as set out below:

Parts Ammonium nitrate $82 Sodium nitrate I20 Water I35 Sugar 50 Continued Pans (iilsonite 6 (iuar gum 4 Thiourea l The above blend of materials hereinafter referred to as the second stock material was used in Example 6 to l2 inclusive. These Examples demonstrate the sensitivity characteristics of uncrosslinked compositions according to our invention after they have been stored for a period of time in comparison with a conventional prior art composition.

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.

EXAMPLES 7 TO 9 INCLUSIVE In these Examples there was added to and blended with 900 parts of the second stock material described hereinbefore the amounts set out in Table I of the "Atomised Aluminium Powder ZOO/Dust of Example I and of the modified aluminium powder of Example 3. The resultant explosive slurry compositions were cartridged in cardboard tubes of 2 inches diameter and stored for the times as set out in Table 1. After this time the cartridges were detonated and minimum amount of pentoliterequired to detonate the cartridges was determined. The results obtained are set out in Table l.

TABLE 1 Example 7 Example 8 Example 9 Atomised Aluminium Powder ZOO/Dust 80 pans pans 40 parts Modified aluminium powder 20 pans 40 pans 60 parts Storage Time (Days) Amount of pentolite used (grams) ll) 4 4 2 l5 4 4 3 l5 l0 4 l0 l5 l5 10 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.

TABLE 2 Example l0 Example ll Example l2 Atomised Aluminium Powder 200/ Dust parts 60 parts 40 pans Modified aluminium powder 20 pans 40 pans 60 pans Storage Time (Days) Amount of detonating material used 1 l0 g pentolite l0 g pentolite 4 g pentolite 2 l0 g pentolite 4 g pentolite 4 g pentolite 3 4 g pentolile l X No. 8 Al detonator l X No.6 Cu detonator Ill* 4 g pentolite [X No. 8 Al detonator 20g pentolite 53 [0 g pentolite l X No. 6 Cu detonator l X No. 6 Cu detonator 79 l0 g pentolite 10 g pentolite *The composition of Example l2 after 10 days storage was detonated in a canridge of l inch diameter.

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.

EXAMPLE 17 To 100 g of a 0.05% solution of abietic acid in toluene there was added 10 g of a non-hydrophobic aluminium powder 99% of which passed through a 350 BS mesh sieve. The mixture was stirred for 1 hour at 35C and the resultant solid product was separated from the reaction mixture by filtration and thereafter dried at room temperature for 5 days. The

resultant dried product was in the form of hydrophobic particles. 0.012 g of abietic acid had been removed from the solution during the reaction period. When 2 parts of the product prepared as described above was added to 98 parts of the first stock material described hereinbefore there was obtained an explosive composition which when cartridged in 3 inch diameter tubes was exploded using grams of pentolite.

What is claimed is.

1. In 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 polymerized rosin and wherein said further material constitutes from 0.01 to 0.2% w/w of said detonation sensitizing material.

2. In a slurry explosive composition of matter according to claim 1 wherein 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 the combination with said composition of from 1 to 10 parts 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 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 2% w/w of said detonation sensitizing material, all parts being parts by weight per parts by weight of said composition.

3. A 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.

4. A 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.

5. A 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.

6. A 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.

7. A composition of matter according to claim 1 wherein said bonded material is derived from sodium abietate.

8. A composition of matter according to claim 1 wherein said bonded material is derived from a modified rosin.

9. A composition according to claim 1 wherein said bonded material is derived from a saponified hydrogenated rosin.

10. A composition according to claim 1 wherein said bonded material is derived from abietic acid.

11. In a process of blasting wherein a slurry explosive composition of matter is loaded into a borehole and detonated therein the improvement which comprises the use of a composition of matter according to claim 1 as the slurry explosive composition.

UNITED QTATES PAIEN'I ovum; CERTIFICATE OF CORRECTION PATFNT NO. 3,919,013

uAnu

INVENTOWS) 3 November ll, 1975 Richard Fox and David Gilbert Hay It IS certrtred that error appears 1n the ab0ve|dentttied patent and that said Letters Patent are herehy curre'tted as shown below On the front page format, after paragraph [21], insert:

-[30] Foreign Application Priority Data l2 a o o 0 o o 0 v o 0 QPA Column 3, line 5 change "primarie" to --pimaric-- Column 3, line 58 change "conbustible" to --combustible- Column 10, lines 25-26 change "the improvement wherein" to --being characterized in that- Signed and Sealed this thirtieth D f March 1976 [SEAL] A ties r:

RUTH C. MASON Allcsrmg Officer C. MARSHALL DANN 'ummistt'inm'r of Pan'nls and Trademarks

Claims

1. IN A SLURRY EXPLOSIVE COMPOSITION OF MATTER COMPRISING AT LEAST ONE OXYGEN RELEASING SALT SELECTED FROM THE GROUP CONSISTING OF AMMONIUM NITRITE, CHLORATE AND PERCHLOTATE, ALKALI METAL NITRITES, CHLORATE AND PERCHLORATES, AND ALKALINE EARTH METAL NITRITES, CHLORATES AND PERCHLORATES, WATER, AND AT LEAST ONE FUEL SELECTED FROM THE GROUP CONSISTING OF WATER SLUBLE FUELS, WATER SOLUBLE OR SPARINGLY WATER SOLUBLE NONMETALLIC FUEL AND METALLIC WATER INSOLUBLE FUEL, THE COMBINATION 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 POLYMRIZED ROSIN AND WHEREIN SAID FURTHER MATERIAL CONSTITUTES FROM 00.01 TO 0.2% W/W OF SAID DETONATION SENSITIZING MATERIAL.

2. The solid propellant composition of claim 1 in which the graphite fibers comprise from about 0.5% to about 10% by weight based on the weight of the solid propellant composition.

3. The solid propellant composition of claim 1 in which the propellant composition is of the single base type.

4. The solid propellant composition of claim 1 in which the propellant composition is of the double base type.

5. The solid propellant composition of claim 1 in which the propellant composition is of the triple base type.

6. The solid propellant composition of claim 1 in which the propellant composition is of the composite type.

7. The solid propellant composition of claim 6 in which the composite propellant comprises an inorganic oxidizing agent and a binder prepared from carboxyterminated polybutadiene.

8. The solid propellant composition of claim 7 in which the oxidizing agent is ammonium perchlorate.

9. The solid propellant composition of claim 6 in which the oxidizing agent is an organic type oxidizing agent selected from the group consisting of cyclotrimethylene trinitramine, cyclotetramethylene tetranitramine, pentaerythritol tetranitrate, ethylene dinitramine, and mixtures thereof.

10. The solid propellant composition of claim 1 in which the composition is in the shape of a propellant granule having a longitudinal axis and a subStantial proportion of the graphite fibers are oriented parallel to said longitudinal axis.