US3449181A - Aqueous slurry type explosive containing the combination of nitrite and sulfamate and/or sulfamic acid as aeration agent - Google Patents

Description

United States Patent O A UEOUS SLURRY TYPE EXPLOSIVE CONTAIN- NG THE COMBINATION OF NITRITE AND SULFAMATE AND/R SULFAMIC ACID AS AERATION AGENT Robert J. Armautrout, Lake Hopatcong, N.J., and Burton C. Person, Virginia, Miuu., assignors to Hercules Incorporated, Wilmington, DeL, a corporation of Delaware No Drawing. Filed Dec. 29, 1967, Ser. No. 694,387

Int. Cl. C06b 1/04- U.S. Cl. 149-60 llClalms ABSTRACT OF THE DISCLOSURE This invention relates to inorganic oxidizer salt explosives of the aqueous slurry type containing oneor more of a class of nitrites for aeration of the slurry, to vary the slurry density, in combination with an additive component for regulation of the aeration rate. An other aspect of this invention relates to the above-described nitrite-addi-tive combination as an aeration agent for such slurry type explosives. Other aspects of the in-. vention 'will 'be'apparent in light of the accompanying disclosure and the appended claims. Y

Inorganic oxidizer salt blasting compositions of the aqueous slurry type have had rather wide use in the explosives industry in recentyea'rs. These compositions contain an inorganic oxidizer salt, or a mixture of such salt-s, as the basic explosive ingredient, water, 'a sensi-tizer such as TNT, tetryl, PETN, a finely divided metal such as particulate aluminum or megnesium-aluminum alloy, or smokeless powder, and a thickener to impart additional consistency to preclude settling of the individual ingredients and to .facilitate handling. Such inorganic oxidizer salt blasting compositions are disclosed and claimed in US; Patents 2,836,484, 2,930,685, 3,235,425 and others.

In US. Patents 3,288,658 and 3,288,661, each assigned to Hercules Incorporated, are disclosed incorporation of a gas into an aqueous slurry type inorganic oxidizer salt explosive for the regulation of density and hence sensitivity and explosive strength. Direct injection of air into the slurry is described in both said patents and in situ gas generation is additionally disclosed in US. 3,288,658. In the copending application of Albert, Ser. No. 607,259, filed Jan. 4, 1967, a class of inorganic nitrates is disclosed and claimed as improved in situ type aeration agents for the above-described aqueous slurry type explosives; and in copending application of Albert et al., Ser. No. 607,261, also filed Jan. 4, 1967, is disclosed and claimed a combination of one or more of the same class of inorganic nitrites together with one or more of a class of inorganic carbonates and Ibicarbonates, as an aeration agent, in accordance with which gas generation for the in situ aeration is more promptly initiated than when the nitrite functions as sole aeration agent.

Numerous advantages have accompanied the use of an inorganic nitrite, above described, as an aeration agent. However, the rate of gas liberation in the above described aqueous slurry type explosives containing the nitrite as sole aeration agent has been found to be unduly low for numerous applications. For example, when so utilizing the nitrite and the slurry is pumped into a borehole, the gas liberation rate is generally too low to enable a prompt determination of the extent of build, i.e., the final height of the explosive column, and hence there is a delay in the loading operation; and further, if it is necessary that the borehole be promptly stemmed, there is not sufiicient time for reaching the final build and hence the extent of useful dispersion of the gas in the explosive is limited. When packaging the slurry in bags, the low rate of gas liberation by the inorganic nitrite aeration agent precludes prompt development of final slurry density with concomitant delay in final handling for shipping, storage or use of the packaged explosive.

The invention is based on the discovery that in inorganic oxidizer salt explosives of the aqueous slurry type containing an inorganic nitrite, above described, as the aeration agent, the rate, and control, of aeration can be increased manifold when the nitrite is in combination with a minor, or additive, proportion of sulfamic acid, certain sulfiamates, or a mixture of any of those materials. The invention significantly shortens the length of time heretofore necessary for aeration of the aqueous slurry when utilizing the nitrite as the sole aeration agent and hence eliminates delays formerly encountered in boreholes loading and packaging under those conditions.

- In accordance with the invention there is provided, as a new aeration agent for inorganic oxidizer salt explosives of the aqueous slurry type, at least one inorganic nitrite selected from the group consisting of sodium nitrite, potassium nitrite, calcium nitrite, barium nitrite, and silver nitrite in combination with a sufiicient amount of an additive component to increase the rate of said aeration to above that of said inorganic nitrite alone, and said additive component being at least one of the group consisting of sulfamic acid, ammonium sulfamate, potassium sulfamate, and sodium sulfamate. The aeration agent generally contains the additive component in a mole ratio to the inorganic nitrite above about 0.111 and up to about 20:1. A now preferred agent of the invention is sodium nitrite in combination with sulfamic acid and/or ammonium sulfamate.

Further in accordance with the invention there are provided aerated inorganic oxidizer salt explosives of the aqueous slurry type in which the aeration agent is the above-described combination of inorganic nitrite and additive component generally present in an amount sufficient to provide for a lowering of density of the slurry explosive, upon aeration, to between 30 to percent of the maximum. Generally, the slurry type explosive contains the aeration agent of the invention in an amount within the range of about 0.002 to 2 weight percent, more often from about 0.015 to about 1.5 percent.

In preferred practice, the slurry type com-positions of the invention, on a weight basis, contain from about 20-75 percent of the inorganic oxidizer salt, from 4-60 percent sensitizer, from 4-35 percent water, from 0.1 to 5 percent thickener and, the above defined aeration agent, for example, from about 0.005 to about 0.50 percent of total inorganic nitrite with from about 0.01-1.0 percent of the additive component.

By the term oxidizer salt as is well known in the explosives art, is meant one which, under the conditions of the detonation supplies oxygen for the oxygen balance required. Ammonium nitrate is in many instances the only oxygen-supplying salt component. However, other inorganic oxygen-supplying salts can be used alone or with ammonium nitrate as a supplementary oxidizer salt. Of these, the alkali metal nitrates are now preferred. Exemplary oxygen supplying salts that can be used alone or together with ammonium nitrate as supplementary oxidizer salts are alkali metal and alkali earth metal nitrates and perchlorates (including ammonium) as for example, sodium nitrate, magnesium nitrate, calcium nitrate, potassium nitrate, barium nitrate, sodium perchlorate, ammonium perchlorate, calcium perchlorate and magnesium perchlorate.

Often when ammonium nitrate is utilized with a supplementary salt, it comprises at least a major proportion, i.e., at least 50 percent of the total oxidizer salt component, however, weight ratios of ammonium nitrate to supplementary oxidizer salt, sodium nitrate now preferred, are generally in the range of from about 4:1 to 0.321.

Particle size of the oxidizer salt ingredients is not critical. For example, ammonium nitrate can consist of prills, such as used in the fertilizer industry, or it can be granular and in that form vary from coarse to fine. Other oxidizer salt ingredients are generally of comparable particle size.

The compositions of the invention are in most instances insensitive to detonating action of a commercial No. 8 blasting cap but detonatable by conventional booster charges of PETN (pentaerythritol tetranitrate), RDX (cyclotrimethylenetrinitramine), Pentolite (PETN-TNT), tetryl, Composition B (RDX-TNT), and the like. One booster advantageously employed is a dispersion of a crystalline high explosive e.g., PETN or RDX, in a plastic carrier such as described in US. Patent 2,965,466 and which is detonated by either a commercial blasting cap or detonating fuse.

The sensitizer can be smokeless powder, or any suitable secondary explosive such as Composition B, PETN, TNT, RDX, tetryl or the like, or a non-explosive ingredient such as a -finely divided metal, e.g., aluminum or an aluminum-magnesium alloy, or fuel oil, DNT, and the like.

Suitable thickener components of the composition of the invention include carboxymethylcellulose, methyl cellulose, water soluble starches, cereal flour and plant gums such as guar gum, which is now preferred.

Often the use of particulate metal fuels such as aluminum, silicon, and the like, is advantageous in the present compositions, in any suitable amount, say, up to about 40 weight percent, often up to about 25 percent, but generally at least one percent. Formulations based on nonexplosive fuels are advantageously employed in the practice of the invention exemplary of which are the soluble polyalcohols such as ethylene glycol and carbohydrates such as cane sugar. Nonsoluble fuels such as ground coal, powdered sulfur, fuel oil and other hydrocarbons are also useful when suitably dispersed. Generally, the amount of fuel present in the formulation is selected so as to provide an overall oxygen balance of 0 or less.

Density of the slurry type explosive compositions of the invention in the order of 0.55 gram/cc. and lower can be achieved by action of the aeration agent above described. However, densities of about 0.7 gram/cc. are

generally the lowest utilized. By way of example, assuming an initial density, prior to any aeration action, of 1.4 grams/cc. and utilizing sodium nitrite as the aeration agent, about 0.22 part of the nitrite per 100 parts slurry would alfect the necessary density lowering, i.e., to 0.7 gram/ cc. However, for a smaller degree of density lowering a proportionately lower amount of nitrite is utilized, such as for example, 0.005 part of sodium nitrite in 100 parts of the slurry.

The amount of the sulfamic acid and/or sulfamate component added to the slurry compositions depends upon the degree of increase in aeration rate that is desired. Generally, from 1 to 3 moles of sulfamate is utilized for each mole of nitrite although in those instances wherein relatively high rates of aeration are desired significantly higher proportions of the sulfamate are utilized as, for example, more than 15 times as much. Often, when utilizing a sulfamate or mixtures thereof, i.e., without sulfamic acid, as the additive component, it is necessary to add a supplementary acid, or an acid salt, e.g., fumaric acid or sodium hydrogen sulfate, to decrease pH of the resulting formulation to a sufficiently low value to accomplish the desired increase in aeration rate. Thus, using a sulfamate or mixtures thereof, in the absence of sulfamic acid the pH of the resulting slurry may often be in the order of, say, from 5 to 6. However, at that pH we have discovered that the effect of the sulfamate additive on aeration rate is markedly less than when it is present at a somewhat lower pH, say, in the order of from 3 to 5.

In those instances in which sulfamic acid is used alone, the maximum amount contemplated is generally about 0.1 part per 100 parts (weight basis) of slurry, and in any event preferably does not exceed that which would produce a resulting slurry pH less than about 2.5. At pHs below that level, the stability of the slurry formulation is uncertain, and particularly so when the guar gum is present, the latter undergoing acid hydrolysis at an appreciable rate at such low pH levels when the temperature of the resulting slurry is above about F. Preferably, the proportion of sulfamic acid introduced into the slurry composition is limited to that which provides for a composition pH of about 3.5; and that amount is in the order of 0.08 part, or less, per 100 parts (by weight) of slurry.

In general practice, it is advantageous to utilize a combination of both sulfamate and sulfamic acid, as the additive component inasmuch as each provides a different rate of aeration at different pH levels. In this manner aeration rate can be controlled over a broad range within the necessary pH requirements, particularly advantageously when guar gum is the thickener component. When utilizing a combination of sulfamate and sulfamic acid, as the additive component, the sulfamate to sulfamic acid mole ratio can be at any suitable level, although it is advantageously at least about 1:1.

It is required, in order that the slurry aeration proceed, that the slurry pH must be on the acid side, generally below about 6 and preferably from 3.5 to 5. Although a lower pH, and particularly a pH lower than 3 can be utilized, such is often disadvantageous from the standpoint of slurry instability that may accompany these conditions dependent upon temperature, and especially when guar gum is a thickener component, as above described.

The use of sulfamic acid as at least a part of the additive component is particularly preferred when the slurry type explosive is to be delivered directly to the borehole inasmuch as the sulfamic acid provides for an almost instantaneous reaction of the nitrite salt to liberate the small gas particles, often substantially quantitatively, and in most instances at an efiiciency of at least percent. The use of sulfamic acid is further advantageous when certain impure grades of aluminum are present in the formulation as a fuel or a sensitizer which tend to raise the pH of the mixture. In such instances the use of sulfamic acid counteracts the pH increase effect of the aluminum to adjust final pH to within the desired range, often at a level of from about 3 to 4.

The invention is illustrated with reference to the following examples which demonstrate the use of ammonium sulfamate, and sulfamic acid, to obtain a manifold increase in the aeration rate of nitrite-aerated slurry type compositions.

The formulations of Examples 1-5 set forth in Table I below were made up as follows:

To the mixer, and in the sequence shown (all additions made with mixing):

EXAMPLE 1 (1) Add the ammonium nitrate in water as an 80 percent solution at 180 F. (2) Add the pine oil and the balance of the water not to be required elsewhere.

(3) Add /2 of the natural guar gum dispersed in /2 of the ethylene glycol and mix until thickening begins.

(4) Add the smokeless powder, water wet, and the sodium nitrate.

' (5) Add the remaining guar gum dispersed in the remaining ethylene glycol. v

,(6.) Add the sodium nitrite and the ammonium sulfamate (except, see one formulation with no ammonium sulfamate), each dispersed in a small portion of water retained from the formula weight of water.

(7) Add the potassium pyroantimonate dispersed in a small portion of retained ethylene glycol.

(8) Add the fumaric acid dispersed in a small portion of water. I

EXAMPLES 2 AND 3 (1)Add the water (less 0.875 part), the smokeless powder, the pine oil and 17 parts of the ammonium nitrate, at a temperature of 85 90 F.

(2) Add the guar gum dispersed in the ethylene glycol (less 2.26 parts).

(3) Add 0.04 part of the fumaric acid.

(4) Add the sodium nitrate and the remaining ammonium nitrate. 1

. Taking 96.5 parts of the above mixture, the test formulations were completed as follows:

- Example 2 (a) Add the potassium antimonate (0.137 part) and the fumaric acid (0.113 part) dispersed in 2.26 parts of ethylene glycol.

Example 3 EXAMPLE 4 ('1) Add the ammonium nitrate (93 percent as an 80 percent solution in water, and 7 percent as prills), the sodiumnitrate, pine oil and the smokeless powder (waterwet).

(2) Add /2 of the guar gum dispersed in /2 of the ethylene glycol at a slurry temperature of 125 F. and mix until thickening begins.

(3) Add the remaining guar gum dispersed in the remaining ethylene glycol.

(4) Add the ammonium sulfamate and the sodium nitrite each dispersed in a small portion of water retained from the formula weight of the Water.

(5) Add the potassium pyroantimonate dispersed in a small portion of ethylene glycol retained from the formula weight of glycol.

(6) Add the fumaric acid dispersed in a small portion of the glycol.

6 EXAMPLE 5 (1) Add the ammonium nitrate (as an 80 percent solution in water), the sodium nitrate and the balance of the water.

(2) Add the guar gum dispersed in half of the ethylene at a slurry temperature of 123 F.

(3) Add the remaining ethylene glycol.

(4) Add the aluminum.

(5) Add the ammonium sulfamate, the sodium nitrite, the potassium antimonate and the fumaric acid each successively dispersed in a small portion of water retained from the formula weight of water.

TABLE I Parts by Weight Example Water 18. 0 16. 8 16. 8 16. 1 18. O Smokeless Powder 32.0 31. 4 31. 4 32.1 AIDIllOl'llllIll Nitrate 32. 0 37. 3 37. 3 37. 6 50. 6 Sodium Nitrate 12. 5 9. 7 9. 7 9. 7 15. 2 Ethylene Glycol 2 4. 4-3. 4 3. 7 3. 7 3. 1 7. 0 Aluminum 3 8. 0 Pine Oil 0.1 0.05 0 05 0. l Guar Gum 0. 8 0.7 0. 7 0.8 1. 2 Potassium Pyroantimonate 4 0. 05 137 0. 137 0.08 0. 07 Sodium Nitrite.-. 0. 07 125 0. 125 0. 055 0.023 Fumaric Acid 0. 05 153 0 04 0. 1 0. 07

onium Sulfamat 5 0-1. 0 04 Sulfamic Acid pH after 24 hours Specific Gravity after 24 hours Detonation Rate, meters per second at 42 F. (5 inch diam.) 5, 400 4, 900 Primer, grams Pentolite 140 1 Example 1, Ground 40 mm.

2 Decreased from 4.4 to 3.4 as ammonium sulfamate (01.0) was substituted for ethylene glycol, includes double base sporting powder.

3 Balled foil, includes double base sporting powder.

4 Potassium pyroantimonate (crosslinking agent for the guar gum).

' In examples 1 and 4 about 90 percent potassium pyroantimonate, with In Table II are shown Examples lA-G inclusive, each of which is the formulation of Example 1 containing ammonium sulfamate at a different content level within the (l-1.0 range (see Example 1). The formulation of Example 1 (Table I) in which the ammonium sulfamate content is 0 (also Example 1A, Table 11) is typical of packaged inorganic oxidizer salt explosives of the aqueous slurry type.

Table II shows the effect of the presence of various proportions of ammonium sulfamate on the aeration rate in the formulation of Example 1A containing only sodium nitrite as the aeration agent. As shown in Table II the final pH in each of the formulations was in the range of 4.0 to 4.4, the initial density in all instances being 1.42 grams/cc. and the mixing temperature being the same in all cases, i.e., 90 F. Aeration in each of the Examples lA-G was observed by noting the expansion of a sample of the formulation in an upright 2 /2 inch diameter clear polyethylene bag, the density change at the time intervals shown in Table II being based upon the change of column height at each interval. The data demonstrate that with an increased proportion of the ammonium sulfamate ingredient the aeration rate was greater, i.e., a shorter period of time was required to accomplish a given density change. Further indicative of the increased aeration rate is shown, with reference to Example 1B (Table II), that with only 0.1 percent ammonium sulfamate in the formulation there was a 10-fold decrease in the time required to reach a density of 1.16 grams/cc. Even after 24 hours in the absence of ammonium sulfa-mate (Example 1A) only 62 percent of the final density reduction had occurred, a density of 1.08 grams/cc. being the limiting density; this lowering having been accomplished by aeration activity of the sodium nitrite aeration agent alone.

7 With only 0.1 percent of ammonium snlfamate present, Example 1B, about 88 percent of the total reduction had taken place during the same time.

TABLE II Example 1A 1B 1C 1D 1E 1F 1G Ammonium sulfamate, wt.

percent 0. 1 0. 2 0. 4 0. 6 0. 8 1. 0 Final pH 4.0 4. 2 4. 2 4. 2 4. 1 4. 4 4. 1 Initial Density, grams/cc... 1. 42 1.42 1. 42 1.42 1.42 1.42 1. 42 Time to Decrease Densityz To 1.38, minutes.. 32 18 16 10 8 6 4 To 1.33, minutes. 85 44 35 23 17 12 10 To 1.29, minutes 150 80 54 35 28 24 18 To 1 25, minutes 260 124 75 53 40 34 30 To 1 22, minutes 600 144 90 65 58 47 42 To 1 19, minutes... l, 440 194 140 85 75 62 57 To 1 16, minutes .2,880 289 188 123 110 87 80 To 1.13, minutes.-. 273 163 155 117 110 Specific Gravity after 24 hours 2 1. 21 1.12 1. 12 1 11 1. 09 1 09 1. 08

1 At 70-75" F., grams/cc. 2 Samples held at 70 F.75 F.

Examples 2 and 3 of Table I demonstrate typical formulations for charging directly to the borehole, i.e., they are typical down-the-hole formulations in which the cross-linking agent and nitrite aeration agent are mixed in the slurry as it is pumped into the borehole. Examples 2 and 3, with further reference to Table III, demonstrate the effect of sulfamic acid as a component of the aeration system of the invention. The pHs shown by Examples 2 and 3 are below those generally preferred inasmuch as they favor extensive acid hydrolysis of the guar gum thickener at higher temperature levels. However, in many instances the temperature in the borehole is sufficiently low that, even at pH levels in the order of those of Examples 2 and 3, hydrolysis of the gum, being time and temperature dependent, the stability of the formulation remains essentially unchanged over a period of several weeks. It is, however, general practice to maintain the pH of the slurry in the borehole above about 3, generally from about 3 to 4 when utilizing sulfamic acid as the additive component.

Density and density change for each of the formulations of Examples 2 and 3 of Table I were determined in the same manner described with reference to those determinations for Examples lA-G shown in Table II, and are summarized in Table III. The data of Table III demonstrate the manifold rate of reaction of the sodium nitrite in the presence of the sulfamic acid. Thus, the formulation of Example 3 (Table III) containing the sulfamic acid achieved 82 percent of the desired density reduction in 7 minutes whereas in the absence of the sulfamic acid, i.e., fumaric acid added to regulate pH, only 18 percent of this reduction took place during the same time.

TABLE III Example 2 (Table 1) Example 3 (Table I) Fumaric Acid sulfamic Acid Slurry Slurry Time in Volume, Density, Time in Volume, Density, Minutes cc. grams/cc. Minutes cc. grams/cc.

Example 4 of Table I demonstrates compositions of the invention containing smokeless powder also illustrated with reference to Examples 1-3 but having also been tested for detonation rate which was found to be 5400 meters per second at a specific gravity of 1.17.

Example of Table I illustrates slurry compositions of the invention devoid of an explosive sensitizer, i.e.,

being of the nitrocarbonitrate type and having a detonation rate of 4900 meters per second at a specific gravity of 1.21.

The formulations of the invention generally contain sulfamic acid as the additive component alone or combined with a sulfamate ingredient, when the formulation is to be charged into a borehole inasmuch as the use of sulfamic acid results in a lower pH than is possible when a sulfamate additive is utilized alone; and accordingly, a correspondingly higher gas liberation rate is provided for density control during a short period after emplacement. When utilizing a combination of sulfamic acid and sulfamate, the total sulfamate to sulfamic acid mole ratio is generally from about 1:1 to 20:1. pHs as low as 2 to 3 with correspondingly high gas liberation rates can often be utilized in borehole loadings as above described, but are not attained when the additive component is one or more sulfamates alone.

On the other hand when the formulation is to be packaged, the additive is generally a sulfamate or sulfamate mixture alone or in high proportion relative to the sulfamic acid ingredient, inasmuch as the resulting pH is generally above at least 3.0 and more often above 4 and is sufficiently high that it does not adversely afiect stability of the formulation, even if guar gum is the thickener component. This is important in the packaging of the finished slurry type explosive due to the prolonged storage periods and elevated storage temperature conditions often encountered, which would at lower pH levels characteristic of sulfamic acid addition, often fail, due to instability of the formulation under such conditions.

Although, the proportion of thickener component in the explosive compositions of the invention is, in general, not usually in excess of about 5 weight percent, it is more often from 0.2 to 3 percent, dependent upon the particular choice of thickener. When utilizing guar gum as a thickener component, and particularly when it is in crosslinked form, the proportion of guar gum utilized is preferably Within the range of from about 0.2 to 2 weight percent.

As will be evident to those skilled in the art, various modifications can be made or followed in light of the:

foregoing disclosure and discussion, without departing from the spirit or scope of the claims.

What we claim and desire to protect by Letters Patent is:

1. In an inorganic oxidizer salt explosive composition of the aqueous slurry type containing an aeration agent therefor, the improvement comprising as said aeration agent at least one inorganic nitrite selected from the group consisting of sodium nitrite, potassium nitrite, calcium nitrite, barium nitrite, and silver nitrite in combination with a suflicient amount of an additive component to increase the rate of said aeration to above that of said inorganic nitrite alone, and said additive component being at least one of the group consisting of sulfamic acid, ammonium sulfamate, potassium sulfamate, and sodium sulfamate.

2. An explosive composition of claim 1 wherein said aeration agent contains said additive component in a mole ratio to total inorganic nitrite in combination therewith within the range of about 0.1:1 to 20:1.

3. An explosive composition of claim 1 containing from 0.002 to 2 weight percent of said aeration agent.

4. An explosive composition of claim 3 containing, on a weight basis, from about 20-75 percent of said inorganic oxidizer salt, from 4-60 percent sensitizer, from 4-35 percent water and from 0.1 to 5 percent of a thickener component.

5. An explosive composition of claim 4 containing from 0.005 to 0.50 percent total inorganic nitrite together with from 0.015 to 1.0 percent of said additive component.

6. An explosive composition of claim 4 wherein ammonium nitrate is at least 50 percent of the total oxidizer salt component.

7. An explosive composition of claim 6 containing so- References Cited dium nitrate and ammonium nitrate in an ammonium UNITED STATES PATENTS nitrate:sodium nitrate weight ratio Within the range of 3 164 503 N19 Gehrig X fmm to 5 312421019 3/1966 Gehrig 149-60 X 8. An explosive composition of claim 4 containing 5 3288 661 11/1966 Swisstack 149 60 cross-linked guar gum as said thickener component. 3:288:658 11/1966 Ferguson (at-a1 X 9. An explosive composition of claim 8 conta ni g 3,294,601 12/1966 Gordon 149 0 from 0.2 to 2 percent of said cross-linked guar gum.

10. An explosive composition of claim 4 containing BENJAMIN PADGETT Pnmary Exammer' from 0.2 to 3 percent of said thickener component. 10 LECHERT, Assistant Examiner- 11. An explosive composition of claim 4 wherein said U.S. Cl. X.R. inorganic oxidizer salt is sodium nitrate. 14941, 43, 44, 45, 47, 60, 61, 62