US2345582A - Explosive composition - Google Patents

Description

LOSWE QOSITION Claude H. Carey, W A

Atlas Powder Comp corporation of Boise w Del, assignor to at Del. b

No Drawing. Application August 3, 1940, Serial No. 351,213

'17 Claims.

This invention relates to a new type of detonating explosive and improved method of preparing the same comprising water soluble nitrates and a non-explosive, combustible, oily material. An object of the present invention is the production of a water soluble nitrate type explosive having suflicient sensitivity for use as a commercial explosive withoutthe requirement that it be. primed with a cartridge of dynamite or the like.

Another object of the invention is the produc-. tion of such an explosive by the admixture of materials which are in themselves substantially incapable of detonation.

Other objects of the invention will hereinafter more fully appear.

It is known in' the explosive art that for ex- I plosives to be effective in their use they must possess sufiicient sensitivity for satisfactory propagation. Explosive compositions containing a high percentage of ammonium nitrate have been heretofore disclosed, which are not cap sensitive and, for this reason cannot be used in :bl-asting operations as explosives without an auxiliary priming charge. For example, one proposal utilizes a cap sensitive central corein compressed cylinders of an explosive, wherein the nitrate and oily substances has the efiect of reduclng the sensitivity, I have'found that by in-.

corporating such oxygen consuming ingredients with the ammonium nitrate and non-explosive oily substance during the mixing and heating, explosives may be produced which will completely detonate in a 1%" x 8" paper cartridge when initiated by a No. 8 commercial blasting cap. The incorporation of these oxygen consuming ingredients is advantageous in that it permits the full development of the disruptive .7 crystals in intimate contact with thin films of oil,

or fat, are furnished with sufilcient oxidizable material in microscopical, or even molecular dimansions, to ofier an ideal combination for very large mass of the charge was insensitive and required the continuous cap sensitive core throughout the cylindrical charge for a satisfactory detonation and propagation of the explosion. Another proposed explosive requires a powerful booster charge for the purpose of propagating the explosion throughout the insensitive material. There have also'been proposed explosive compositions of colloidal starch and soluble nitrates which are more sensitive than simple mechanical mixtures of the ingredients, but which require a primer or initial detonating charge or a secondary sensitizing component in order that they may be detonated with assurance.

It is well known in the explosive art that a simple mixture of grained ammonium nitrate and a non-explosive oily substance or a coating of a non-explosive oily substance applied as a coating to the grains of ammonium nitrate has too low'a degree of sensitivity to be of practical value as an explosive, especially in smallsized cartridges. Now I have found that mixtures of ammonium nitrate and non-explosive oily substances, when mixed and heated, in the presence of water to form a plastic mass which is conjections and undulations, which are sensitive to rapid decomposition of the constituents when subjected to flame and shock, such as would rev suit from a blasting cap. Grained compositions, by means of agitation and drying, cause comparatively large crystals to be formed without exposed angular surfaces and are coated with an excessive amount of the oily substances which reduces the sensitivity of the particles todetonation. Fragmentation of the hard dried compositions exposes the minute crystals and allows the maximum contact to the propagating wave and flame by outcropping crystals at the surface of the fracture. Moreover, the dried fractured granules present surfaces from the interior which are highly irregular due to the fact that the granules being case hardened before much of the moisture has been rembved only permit shrinkage to take place in the interior of the hardened granule shell by the formation of voids which were occupied by the concentrated solutions of the soluble salts. As a result of the more porous structure of the interior of the granule than the surface, the faces of the fractured particles ofier more minute prodetonation. This is particularly true when other combustible materials such as starch, cereal flours or gelatine are used. The increased sensiverted into strings or vermicelli, and then dried or partially dried to a hard state, followed by fragmentation so as to pass a 14 mesh or finer Tyler standard screen, completely detonated (when substantially dry) in a 1%" x 8" paper cartridge by the initiation ofa #8 commercial blasting cap. Although the addition of oxygen consuming ingredients, such as fine carbonaceous materials, to my ultimate mixtures of ammonium tivlty and explosive force of the explosive by the use of fuels result from their oxidation by the available oxygen in the soluble nitrates.

The oily material employed in the explosive composition of the present invention may be a fatty oil such as cottonseed oil, sperm oil, castor oil, soya been oil, linseed oil, coconut oil and the like, or a fatty oil acid, such as lauric, myristic, palmitic, stearic, or oleic, fatty oil acid derivatives such as aluminum stearate, oleate, etc., or

tivity in obtoined when the a petroleum oil residue which is non-volatile at from 20-50% free fatty acid, about 9.8% of which is palmitic. Of the fatty oil acids suitable for use, I have found oleic to be highly preferable, and petrolatum of the petroleum residues.

For the carbonaceous ingredients of the main fuel, I prefer a material which has the ability to swell and readily absorb water such as corn starch, tapioca flour, corn flour, gum arable, glue or gelatin, end materials rich in mannan such as vegetable ivory nut meal, carob beans, cofiee berries, and date seeds. l have found that substances such as corn meal, starch. and glue, which contain smell amounts of ether soluble oils or fats ere emcacious in promoting sensitivity.

In'addition to the main sensitized ingredient, or ammonium nitrate, I may prefer to add other oxidants consisting of soluble nitrates such as sodium nitrate and potassium nitrate, which will allow the strength or the explosive to vary over a wider range, and meet specific requirements in regard to density, velocity, and fume conditions.

in the preparation of the explosive compositions of the present invention, the water soluble nitrate, and the non-explosive, combustible, oily materiel (together with additional carbonaceous material as a main fuel where it is desired to provide oxygen balance) are mixed with water,

and heated to a temperature in the neighborhood of 120 to 180 F. l have found that the degree of temperature of mixing is not of great importance in securing desirable characteristics of the finished product, but for ease in manufacture by securing an easily workable plastic mass,

the temperature may be varied according to the composition. In general I prefer a temperature of from 120 to 140 F. although the invention is not to be considered limited in this respect as explosive compositions, having desirable sensitivities, may beobtained when mixing temperatures as high as 180 F. are used.

Dining this heating and mixing, the composition becomes a soft, cohesive, plastic mass. Preferably this plastic mass is shredded by slicing with lmives, or by extruding it through orifices, so as to provide (shredded) particles or vermicelli-like material having a relatively large surface area for subsequent conditioning. The particles or vermicelli are rtially dried to a hard state, and thereafter ground or grained to the desired size, followed by complete drying. The invention is not to be considered as limited to this particular manner of graining and coach tionlng the material, however, as other methods will readily occur to those skilled in the art. Thus, for example, the plastic shredded mass me? be dried and ground to the desired porticle size or it may be dried and crushed between rolls to the desired particlesiae.

The proportion or writer employed should be from b to oi the weight of the other mate ria s employed in the mixture. r 1- s. mush water employed n in the weight oi the the neighborhoml oi 11% or essence other ingredients. The water equivalent may be added in the-form of a solution of nitrate of ammonia which serves equally as well as water alone.

The proportion of carbonaceous combustible material such as starch, cereal flour, tapioca flour, and vegetable ivory meal, may vary from 5 to 25% depending on the final oxygen balance of the composite explosive mixture as used in the field.

The non-explosive, combustible, oily material is the sensitizing agent in the explosive composition, and should be present in small amounts within definite limits if optimum sensitivity is to be obtained. Thus, where a petroleum oil residue such as petrolatum or a fatty oil acid is employed in the composition as the sensitizing agent, it should be present in an amount not greater than 3.0% by weight on a dry basis, as

it has been found that greater proportions result in an insensitive product. Combinations of 1.0% paramn and 0.5% oleic acid or 1.0% oleic acid and 0.3% paramn are excellent sensitizers.

In the preparation of the composition, the water soluble nitrate may be in any of the usual forms commonly employed in the explosive industry, or in the form of a water solution of the nitrate. The term coating as hereinafter used will refer to a mixture of 75% paraflln and 25% petrolatum, which is applied to grained ammonlum nitrate for the purpose of preventing moisture absorption in transportation and storage. If desired the ammonium nitrate may be precoated with at least part of the oily sensitizer employed. Although water soluble inorganic nitretes other than ammonium nitrate, as for example, nitrate of soda, may be employed along with ammonium nitrate, it has been found that the sensitivity of the explosive composition tends to decrease as the proportion of such other water soluble nitrates is increased. I have found that in order to obtain the desired sensitivity in these explosive compositions, their water soluble nitrate content should consist of at least ammonium nitrate.

Where the composition is deficient in oxidizable matter and there is a substantial excess of oxygen present in the composition, I may add to the idants. The addition of such materials permits the proper adjustment to be made for theoxygen balance so that ultimate mixture will exert its full disruptive force in the bore hole. By a. variation in the quantity of thevarlous materials as well as their degree of fineness it is possible to vary the strength, density. and velocity of the explosive. i

In the following non-limiting examples of explosive compositions of the present invention, and of method of preparing the some, the parts referred to are parts by weight. Where measured in inches, the sensitivities were determined by the space oi on air gap measured in inches between two out ends or an 1%," x 8" cartridge lying on the grolmd and joined together by 2% wraps of 60 lb. new and the d atom-ting wave initiated by a #6 blasting cap in one of the halves .caused complete detonation of the two half cartridges.

At this stage the mixture becomes a soft, cohesive, plastic mass, which is forced through a square mesh'screen having .084 in. openings, and wire of .041'in. diameter. The grains or vermicelli so produced are then partially dried by means of an air blast having a temperature from 80 to 115 F., so that moisture content is reduced to about 1.6%. The hard, almost vitreous, grains are then fractured and broken by rubbing them over, and through, a wire screen having openings of .039 in., and a wire diameter of .032 in.. A final drying is carried out at a temperature of 1307 F. to 0.44% moisture. The finished product when packed in 1%" x 8" parafiin sprayed paper shells gives an average cartridge count of about 166 cartridges per 50#, and has a. sensitivity of 1" Example 1 Example 4 5 Ingredient g gs, 3 Ingredient 3 ag 53 Ammonium t w 7 oa Pgftoflo Pgfglo 223? t r io r n edifitaaiiijiit: "32 15, 1.06 mmwmnmmmm Total nitrate of ammonia and coatimz 8,700 87.00 The ammonium nitrate and water are thor- Tap 740 660 M oughly mixed, and then the petrolatum added, ggggggggdg ids 5 3 3 6,3 and the mixture thoroughly incorporated in a aci so 50 0.50 steam jacketed dough mixer, and heated to 150 15 F. The amount of water present will be approxi- The dry ingredients of the above composition mately 5.35% of the total mixture. The soft are thoroughly mixed in the dough mixer as in semi-plastic mass is forced throughasquare mesh Example 3 and brought up to a temperature of screen, having .096 in. openings, and .047 in. wire. 180 F. The plastic mass is converted into vermi- The grains or vermicelli so produced are partially celli and air treated as in Example 3, and dried dried by means of an air blast having a temperaat 128 F. The dried material is fragmented in a ture from 80 to 100 F., so that the moisture mill so as to passaTyler standard 14 mesh screen. content is reduced to a point where the grains or The product packed in 1%" x 8" paper shells vermicelli will not coalesce when submitted to sprayed with parafin, yields 148 cartridges per 50 complete drying. The material is further treated 2 lbs., and consistently detonates in the open with a at a temperature of 100 to 140 F. for nearly #6 blasting cap. complete removal of the moisture. The dried Example 5 mass is fragmented by means or a mill, or crushing rolls so as to pass a standard 40-mesb. screen. a Gross Dry Dry The fragmented material when packed mgtedent weight weight weight 1 x 8" parafin sprayed paper shells gives an average cartridge count of 169 cartridges per 50 Grained ammonium nitrate 0.3% Parts Parts Percent hasasensiiivity of itfitiimenaieae' aiisiax:3:31;: it

Example 2 Total ammonium nitrate and coating 1,839 91.85 A composition similar to that in Example 1, $33 1 33 {:53 with the exception that oleic acid is substituted m for petrolatum in the same proportion. After The ammonium nitrate and tapioca flour are prepanflg the composltion in a manner 0 mixed in a jacketed mixer and the solution and h fimshed Product has equal Sensltmtypalm grease added, and the mixture heated with Example 3 mixing to 130 F. The plastic mass is converted into vermicelli and air treated as in Example 3. The grains or'verm'icelli are dried at 135 F., and ingredients ,g gf ag 3 3' passed through crushing rolls so as to pass a Tyler standard 20-mesh screen. The explosive Pam Pam composition so produced when packed in Nitrate oiammonla(0.3% coating).. 7,969 7,969 1%" x 8" parafiin sprayed paper shells gave 169 Ammmmm mate 1 11983 236 cartridges per lbs. and had a sensitivity of 9,205 9205 50 x p 6 $25 700 5.00 95 95 Ingredient 93$ g g' ag The amount of water present approximately (mined ammonium meme 0.5% Pam m Pmm 12% of the total weight of the mixture. The amco t c)-.

------- 7,980 7, mon'ium nitrate and starch are intimately mixed Ammmm and warmed in a jacketed dough mixer, and the Total ammonium nitrate and 9 m 92 22 liquids then introduced. By means of heat from "955' 1 the heating jacket, the temperature of the mass Wo 99 during the mixing is gradually raised to F.

The grained ammonium nitrate and flour are mixed in a jacketed mixer and the oil and liquids added, followed by heating and mixing to F. The plastic mass so produced is passed through a square mesh screen having .084 in. openings, and .041 in. diameter wire. This product is partially dried and then grained through a square mesh screen, having .039 in. openings, and .032 in. diameter wire. The grains are finally dried at a temperature of 166 F. when packed in 1%" x 8" paraflin coated shells'the'stick count was about 17'! per 50 lbs. and these cartridges detonated in the open with a #8 blasting cap.

Emmple 7 An explosive composition prepared as in Example 6, but having raw linseed oil substituted tor the sperm oil. This explosive composition will also consistently detonate in the open with a. #8 blasting cap; when packed 170 1%"x8" cartridges per 50 lbs.

Example 8 Gross D D Ingredient weight weight we t Groined ammonium nitrate (0.3% Ports Pom Percent coatigf) 6, 000 6, 000 Ammo um nitrate solution l, 480 913 Total nitrate of ammonia 8,913 91. 89 1 Water 250 Tapioca flour 590 510 6. 78 Aluminum steerste 100 100 l. 38

Emple 9 I I Gross Dry Dry M Weight Weight Weight Gruined nmmonium nitrate (0.3% Pcflo Part Percent coating) a, son 6. soc Ammonium nitrate solution 1,900 l, 208 Water e00 'lotol ammonium nitrate and cost- 8, 0% 80. 1G Tapioca flour 250 '210 2. 1% Corn menl M0 450 4. 60 Vegetable ivory meal l, 230 l, 205 12. 03 Oleic acid 100 100 1.00

Gross D weight wag]:

Grnined ammonium nitrate (0.3%

The dry ingredients are mixed in a jacketed mixer, and then the liquids added and heated and mixed until a temperature of 180 F. is attained. The would contain opproximotely 11.1% water. The plastic mass so produced is forced through an extruding machine so as to term equal-cor round vermicelli, having on approxlmote crollaocflonnlomotmmllmimvlthpir treatment for case hardening, followed by drying at a temperature from 110 to 170 F. The dried vermicelli is fragmented by crushing or grinding in a mill to pass a -mesh Tyler standsrd screen. The fragmented material when packed 15s 1%" x8" cartridges per lb. case gives s sensitivity of 2". When packed 147 11%" xii" cartridges the sensitivity is about /2.

30* dough i removed and forced through a. screen as transferred to a dry house ond dried for 16 hours at 150 F. After removal from the dry house it is cooled and iragmented by moons of metal rolls to pass a QO-mesh standard screen. A. sensitivity of 2" is obtained with s. #6 esp when posited 43 g in 1%" x 8" paper cartridges yielding: 3163 per 50 lb. case.

It can be seen from the foregoing examples that each or the explosive compositions was capable of being packed in 1% n 8" cortridges to 2. density within the rouge of from M5 to 1% 11%. x 8" cartridges per 50 lb". case, at which den-- sity it was sensitive to detonzition with e. lilo. 0 commercial blasting cap.

The method of preparing the explosive compositions and mixtures of the present invention may be controlled to produce ultimate products of various densities, sensitivities, end velocities. The compositions prepared with higher mining temperstures such as 150 generally hove a. greater density than those prepored with lower mining temperatures in the neighborhood oi F. It is desirable to hovethe combustible redients in as iine a state of subdivision es practical in order to obtain homogeneity.

in many types of blasting operations it is important to have the explosive meet definite re quirements with respect to density and sensitivity. in other words, many blasting operations Y require high buikstrensth. That such high density ammonium nitrate explosives are characterized by having a low sensitivity is well known in the art. By controlling the particle size oi my ultimate mixture it is possible to regulate these characteristics of the explosive.

Also bymixing the fragmented explosive composition of the present invention with straizht ammonium nitrate, a density hlzher than one or a cartridge count as low as 125 1% x 8" cartridges per 50 lbs. may be obtained and particulorly when relotively coarse straight ammonium tridges.

assasea nitrate is employed as set forth in the following example. Thus one part of the explosive com position of Example (passing a 40 mesh screen) is mixed with one part of grained ammonium nitrate with 0.3% coating, said ammonium nitrate passing a 10-mesh screen and 95% being held on a 60-mesh screen. The resulting explosive has the followingapproximate analysis on the dry basis:

Percent Ammonium nitrate 89.7 Tapioca flour 3.5 Vegetable ivory meal 6.0 Oleic acid 0.5

Coating 0.3

This mixture packed in 1%" x 8" paraihn sprayed paper shells gives a'cartridge count of about 129 cartridges per 50 lbs., and detonates in the open with a #8 blasting cap. In this embodiment of the invention, the explosive comprising the fragmented product admixed with straight ammonium nitrate is characterized by sensitivity to detonation with a No. 8 blasting cap even though the straight ammonium nitrate is present in proportions as high as 50% by weight of the explosive. i

Where referred to in this specification and appended claims, the term straight ammonium nitrate" means ordinary commercial grade ammonium nitrate such as conventionally grained ammonium nitrate containing'a small amount of impurities and which generally is coated with a small proportion of a moisture resisting material such as petrolatum, paraflin, etc.

By these various methods of preparation, a nonexplosive oily substance, soluble nitrates, and combustibles may be combined for compositions of desired sensitivity, with cartridge counts in the 1 x 8" size ranging from 125 to 185 and upward, cartridges per 50 lbs. Various combustibles which act as sensitizers and accelerators; as for example, aluminum and term silicon powders may be added to the mixture.

In the foregoing examples and discussions of the explosive compositions of the present invention, their embodiment in cartridge form has been illustrated by reference to 1%" x 8" car- This small cartridge has been chosen for purposes of illustration because the small diameter cartridges are more dimcult to detonate than the larger sizes. This is particularly true where a plurality of cartridges are laid end to end, and the detonation of an end cartridge by a blasting cap must be propagated from one cartridge to another, to detonate the series. this specification, where it is stated that cartridges detonated with a blasting cap it is meant that one or more of a series of'cartridges placed end to end completely detonated unconfined, when detonated with the blasting cap. It is obvious that the explosive composition of the present invention may be embodied in larger diameter cartridges,- which inherently have a greater ability to propagate the detonating impulse. The explosive compositions are also excellently suited for use in loose granular form to be charged directly into the bore hole.

In the foregoing examples, detonation of the explosive composition and mixtures were obtained in the open. Since propagation'of the detonating impulse is always more easily accomplished when the explosive is under confinement of a bore hole, it will be readily apparent to those skilled in the art that the compositions and mixtures of the present invention are of sumcient sensitivity to make them commercially useful without the requirement that they be primed.

The sensitivity of the explosive composition is believed to be due to its physical characteristics, and to a definite uniform physical relationship ofthe various particles to-each other. Since nolocalized supersensltivity can occur, the explosive offers a relatively high degree of safety in its use.

' Furthermore, the handling and transportation of the raw materials necessary for .the production of the composition can be safely carried out as the ingredients themselves are substantially incapable of detonation.

Having fully described the invention what I claim is as' follows:

.1. The process of preparing an explosive com-' position which comprisesintimately incorporating a. water-soluble nitrate consisting of at least ding the plastic mass so produced into coarse,

firm particles, drying the particles to a hard state under conditions such that the particles will not coalesce, and fragmenting the hard particles to pass a 14 mesh screen.

2. The process of preparing an explosive compositionwhich comprises intimately incorporating a water-soluble nitrate consisting of at least .onium nitrate with a small sensitizing proportion-of a fatty oil acid, said incorporation being conducted in the presence of water and heat toi'orm a plastic mass, shredding the plastic mass so produced into coarse, firm particles, drying the particles-to a hard state under conditions such that the particles will not coalesce, and fiasmenting the hard particles to pass a 14 mesh screen.

3. The process of preparing an explosive composition whlch comprises intimately incorporating a water-soluble nitrate consisting of at least 60% ammonium nitrate with a. small sensitizing proportion of petrolatum, said incorporation being conducted in the presence of water and heat to form a plastic mass, shredding the plastic mass so produced into coarse, firm particles, drying the. particles to a hard state under conditions such that the particles will not coalesce,

and fragmenting the hard particles to pass a 14 mesh screen.

4. The process of preparing an explosive composition which comprises intimately incorporatin; a water-soluble nitrate consisting of at least 60% ammonium nitrate with not more than about 3% by weight or a non-explosive oily material, said incorporation being conducted in the presence of water and heat to form a plastic mass. shredding the plastic mass so produced into coarse, firm particles, drying the particles under conditions such that the particles will not coalesce, finaldrying of said particles being conducted at a temperature above F., and tragmenting said particles to pass a 14 mesh screen, said fraenting being conducted after the said particles have been dried at least suiiiciently so that they will not coalesce at a temperature of 100 F.

5. The process as set forth in claim 4 and wherein the incorporation is carried out in the presence of 5% to 12% water and at a temperature ranging from to F.

6. The process of preparing an explosive composition which comprises intimately incorporating a water-soluble nitrate consisting of. at least 80% ammonium nitrate with oxidizable material present in an amount at least suflicient to balance the oxygen content of the nitrate, said material including a small sensitizing proportion of non-explosive, oily material, said incorporation being conducted in the presence or water and, heat to form a plastic mass, shredding the plastic mass 50 produced into coarse, firm particles, drying theparticles to a hard state under conditions such that the particles will not coalesce, and fragmenting the hard particles to pass a 14 mesh screen.

7. The process of preparing an explosive composition which comprises intimately incorporating a water-soluble nitrate consisting of at least 60% ammonium nitrate with oxidizable material present in an amount at least sumcient to balance the oxygen content of thenitrate, said material including a small sensitizing proportion of fatty oil acid, said incorporation being conducted in the presence of water and heat to form a plastic mass, shredding the plastic mass so produced into coarse, firm particles, drying the particles to a hard state under couditions such that the particles will not coalesce and fragmenting the hard particles to pass a 14 mesh screen.

- 8. The process of preparing an explosive com position'which comprises intimately incorporating a water-soluble nitrate consisting of at least 60% ammonium nitrate with oxidizable material present in an amount at least sufficient to balance the oxygen content'oi the nitrate, said material including a small sensitizing proportion 01 petrolatum, said incorporation being conducted in the presence of water and heat to form a plastic mass, shredding the plastic mass so produced intd' coarse, firm particles, drying the particles to a hard state under conditions such that the particles will not coalesce and fragmenting the hard particles to pass a 14 mesh screen.

9. An explosive composition comprising an explosive component consisting or discrete particles of an intimate mixture prepared in accordance with the process of claim 1, said mixture being free of metal and explosive sensitizer ingredients,

, said explosive component, per se, being capable of being packed to a density lower than that corresponding to 145 1%, x 8" cartridges per 50- pound case, at which density and diameter it is consistently sensitive to detonation with a No. 8 cap.

10. An explosive composition comprising an explosive component consisting oi discrete particles of an intimate mixture prepared in accordance with the process of claim 2, said mixture bein free of metal and explosive sensitizer ingredients, said explosive component, per se, being capable of being packed to a density lower than that corresponding to 145 1 x 8" cartridges per 50- pound case, at which density and diameter it is consistently sensitive to detonation with a No. 8

cap.

l1. Anvexplosive composition comprising an ex- 4 plosive component consisting of discrete particles ofan intimate mixture prepared in accordance with the process of claim 3, said mixture bein free of metal and explosive sensitizer ingredients, said explosive component, per se, being capable oi being packed to a density lower than that corresponding to 145 1% x 8" cartridges per 50- poundcase, at which density and diameter'it is consistently sensitive to detonation with, a No. 8

cap.

12. An explosive composition comprising. an exacetates .said explosive component, per se, being capable of being packed to a density lower than that corresponding to 1% x 8" cartridges per 50- pound case, at which density and diameter it is consistently sensitive to detonation with a No.

8 cap.

13. An explosive composition comprising an explosive component consisting of discrete particles of an intimate mixture prepared in'accordance with the'process of claim 6, said mixture being free of metal and explosive sensitizer ingredients, said explosive component, per se, being a capable of being packed'to a density lower than that corresponding to 145 1 /4)! 8" cartridgesper 50-pound case, at which density and diameter it is consistently sensitive to detonation with a No., 3 cap.

14. An explosive composition comprising an explosive component consisting of discrete particle's-of an intimate mixture prepared in accordance with the process of claim '7, said mixture being free of metal and explosive sensitizer ingre dients, said explosive component, per se, being capable of being packed to a density lower than that corresponding to 145 1% x 8" cartridges per 50-pound case, at which density and diameter it is consistently sensitive to detonation with a No. 8 cap.

15. An explosive composition comprising an explosive component consisting of discrete particles of an intimate mixture prepared in accordance with the process of claim 8, said mixture being free of metal and explosive sensitizer ingredients, said explosive component, per se, being capable 01' being packed to a density lower than that corresponding to 145 1% x 8" cartridges per 50-pound case, at which density and diameter it is consistently sensitive to detonation with a No. 8 cap.

16. An explosive composition comprising an explosive component consisting of discrete particles of an intimate mixture prepared in accordance with the process of claim 6, said mixture being free 01 metal and explosive sensitizer ingredients, said explosive component, per se, being capable of being packed to a density lower than that corresponding to 145 1% x 8" cartridges per fail-pound case, at which density and diameter it is consistently sensitive to detonation with a No. 8 cap and, admixed with said explosive component, straight ammonium nitrate.

1'7. An explosive composition comprising an explosive component consisting of discrete particles of an intimate mixture prepared in accordance with the process 01 claim 6 but wherein the particles are fragmented to pass a 40-mesh screen, said mixture being free of metal and explosive sensitizer ingredients, said explosive component, per se, being capable of being packed to a density lower than that corresponding to 145 1% x 8" cartridges per til-pound case, at which density explosive component, straight ammonium nitrate J present in a proportion not greater than 50% by weight or the explosive, said explosive having a a density corresponding to from 125 to 1% x 8" cartridges per ISO-pound case and being sensitive to detonation with a No. 8 cap.

- CLAUDE H. CAREY.