US3881970A - Explosive composition having a liquid hydroxyalkyl nitrate as sensitizer - Google Patents

Abstract

Hydroxyalkyl nitrates, particularly ethylene glycol mononitrate, propylene glycol mononitrate and hydroxychloropropyl nitrate are employed as part or whole replacements for nitroglycerine and/or ethyleneglycol dinitrate in substantially non-aqueous gelatins, semi-gelatins, dynamites and dry explosive compositions.

Description

United States Patent 1 [111 3,881,970

Falconer et al. 1 May 6, 1975 EXPLOSIVE COMPOSITION HAVING A [58] Field of Search 149/88, 38, 47, 39, 60, LIQUID HYDROXYALKYL NITRATE AS 149/76, 102-105 SENSITIZER [75] Inventors: Errol Linton Falconer, Mont [56] References Cited Saint-Hilaire, Quebec; Harold UNITED STATES T S William Holden St, Hilaire 4 1972 4 4 Quebec, both of Canada 3 653 992 I Fee 1 9/ 7 X [73] Assignee: Canadian Industries Limited, Primary Examiner-Stephen J. Lechert, Jr.

Montreal, Quebec, Canada Attorney, Agent, or FirmDonald G. Ballantyne [22] Filed: Nov. 28, 1973 [2]] Appl. No.: 419,678 [57) ABSTRACT Hydroxyalkyl nitrates, particularly ethylene glycol Relamd Apphcauo Dam mononitrate, propylene glycol mononitrate and cominualion-ifl-parl 0f 1 hydroxychloropropyl nitrate are employed as part or lg72- abandoneda whole replacements for nitroglycerine and/0r ethyl eneglycol dinitrate in substantially non-aqueous gela- [52] US. Cl. 149/47; 149/76; 149/88; tins, sempgdatins, dynamites and dry explosive 149/92; 149/93; 149/102; 149/103; 149/104; positions 7 Claims, No Drawings EXPLOSIVE COMPOSITION HAVING A LIQUID HYDROXYALKYL NITRATE AS SENSITIZER This application is a continuation-in-part of Ser. No. 305,337 filed Nov. 10, 1972, now abandoned.

This invention relates to a sensitizing agent for substantially water-free explosive compositions and hence to such explosive compositions deriving novelty through the presence therein of the said sensitizing agent.

In the explosives art it has long been a desideratum to provide a safe, economic and practical substitute for nitroglycerine and ethylene glycol dinitrate sensitizers, generally referred to as NO and EGD respectively, in explosive compositions of the types generally known as gelatins, semi-gelatins and dynamites. Since NG and/or EGD are hazardous to manufacture and to formulate into useable explosive mixtures and since the vapours of NG and/or EGD frequently produce undesirable physiological effects on individuals exposed thereto, their use poses a continuing problem in the explosive industry. It had been predicted that the non-toxic aqueous slurry explosives consisting of oxidizer salt/fuel mixtures in a gelled water matrix would eliminate most of the undesirable characteristics of NG/EGD-based explosives and eventually displace many of them from the market. While to a substantial extent this has happened, it has not been possible to match the sensitivity and power of NG/EGD/based explosives, especially in small diameters without adding to the aqueous slurries costly sensitizing materials. The need continues, therefore, to employ NG/EGD as explosive sensitizers and the search for safer substitutes for these sensitizers has like-wise continued.

Ideally, an explosive sensitizer should possess the economy and strength of conventional nitroglycerine/ ethylene glycol dinitrate without the explosion and toxicity hazards associated therewith and at the same time the sensitizer must be fully compatible with the mixture of ingredients of an explosive compostion so as to produce the optimum in blasting performance. Many sensitizers having a range of orders of sensitization are known in the explosives art which have particular utility in various types of explosives compositions. In addition to the liquid nitric esters like NG and EGD, these sensitizers include, for example, aromatic nitro compounds such as trinitrotoluene, nitroamine compounds such as nitroquanidine, powdered metals such as aluminium, nitrocellulosoe, smokeless powder, metalloids such silicon, and others Each sensitizer finds specific utility in admixture with other compatible ingredients in particular types of explosive compositions.

In the field of sensitized slurry explosives, for example Henry R. Fee and Elden K. Hurley, disclose in U.S. pat. No. 3,653,992 granted on Apr. 4. l972, that a liquid nitrato-alkanol (hydroxyalkyl nitrate) may be employed as the sensitizing constituent in pumpable or pourable aqueous slurry mixtures containing from 3 to 40% by weight of water. As noted by Fee and Hurley, a liquid nitrato-alkanol is particularly suitable for use as an aqueous slurry sensitizer since, in addition to being safe, it is freely soluble in the salt solution of a slurry, is compatible with the thickened water used in the slurry matrix, is pumpable and requires no separation from the salts and water which are introduced during its manufacture. However, even the improved nitrato-alkanol sensitized slurry of Fee and Hurley has not matched, in terms of senstitivity and density, the NG/EGD sensitized type of explosives of the prior art. Indeed, the compositions of Fee and Hurley require the addition of gas bubbles in order to impart adequate sensitivity to these slurries. Such bubble additives preclude the use of these slurries, at the present state of technology, in the types of packages customarily provided by NG/EGD sensitized explosives, namely, small diameter paper cartridges used in underground mining.

It has now been surprisingly found that hydroxyalkyl nitrates, particularly exemplified by ethylene glycol mononitrate (EGMN), and propylene glycol mononitrate (PGMN) and hydroxychloropropyl nitrate (HCPN), previously disclosed as useful only in aqueous slurry explosives, are fully compatible with NG/EDG and may be successfully employed as part or whole replacements for NO and/or EGD in substantially nonaqueous gelatinous, semi-gelatinous and dry explosive compositions. By substantially non-aqueous is meant a composition containing 3% or less by weight of water.

This invention therefore provides novel, substantially non-aqueous explosive compositions containing as sensitizer constituents thereof hydroxyalkyl nitrates as substitutes for nitroglycerine and/or ethylene glycol dinitrate.

A practical industrial method for the preparation of hydroxyalkyl nitrate (HAN) consists in reacting an oxirane ring compound with an aqueous solution of ammonium nitrate and nitric acid. Ethylene oxide, for example, reacts to form ethylene glycol and EGMN in a diluted solution of nitric acid and ammonium nitrate. Other nitrate salts such as sodium nitrate and calcium nitrate may be included in the reactive mixture. The end reaction product containing EGMN may be subjected to an extraction treatment for recovery of substantially pure EGMN. Alternatively, the end product may in most instances be used as such as a replacement or diluent for NO and/or EGD in conventional explosives of the gelatinous, semi-gelatinuous and dry dynamite types.

The invention is illustrated by the following Examples which are not meant to be limitative as to the scope thereof. Percentages in all Examples are by weight.

EXAMPLE 1 Preparation of Ethylene Glycol Mononitrate (EGMN) One mole (44 g.) of ethylene oxide was bubbled into a solution containing 200 g. of ammonium nitrate, 40 g. of sodium nitrate, g. of 98% nitric acid and g. of water and the mixture was cooled in an ice bath. The reaction was exothermic and the temperature rose from 8to 20C. during the addition of the oxide. As soon as the addition of oxide ceased, the temperature fell rapidly and no ethylene oxide was evolved from the reaction vessel. This indicated a very rapid reaction. The EGMN formed did not separate from the aqueous solution, even when neutralized and saturated with ammonium nitrate/sodium nitrate. The aqueous solution was extracted with methylene chloride and a EGMN yield of 30-35% was obtained. This yield was very low and not representative of actual reaction yield but was the result of simple partition of the product between two phases in which it was completely miscible.

The EGMN isolated was shown by thin-layer chromatography and gas-liquid chromatography to consist mainly of EGMN with small quantities of ethylene glycol, ethylene glycol dinitrate and diethylene glycol mononitrate.

EXAMPLE 2 Another preparation of Ethylene Glycol Mononitrate (EGMN) Ethylene oxide was bubbled into a solution containing 500 g. of ammonium nitrate, 80 g. of sodium nitrate. 160 g. of 98% nitric acid and 280 g. of water. The reaction temperature was maintained below 35C. by external cooling. The oxide was metered into the solution at a rate of 1.2 l./min. while 160 g. of 98% nitric acid was added dropwise over a period of 57 minutes, the time required for the addition of 3 moles of oxide. An additional 6 moles of ethylene oxide and 320 g. of 98% nitric acid were added in a similar manner, after which an extra 4 moles of the oxide were introduced into the system in order to neutralize the excess nitric acid. In a typical case, after a total of 13 moles of the oxide had been absorbed, 2 ml. of 28% ammonium hydroxide solution (p 0.90) were required to bring the pH of the final solution to 7.0 A material-balance calculation in the reaction products predicted approximately the following composition:

Ammonium nitrate 24.1 Sodium nitrate 3.9 Water 1 1.5 Ethylene glycol mononitrate 51.4 Ethylene glycol 9.1

EXAMPLES 4 8 Preparation of EGMN In a pilot-plant batch reaction process as described in Example 2, the following EGMN liquors were produced. The quantities shown are expressed as percent by weight.

Example 4 5 6 7 8 Ammonium nitrate 23.4 22.0 24.7 23.9 22.8 Sodium nitrate 4.2 4.2 3.8 3.8 4.0 Water 12.8 15.7 11.9 11.5 15.3 EGMN 54.2 51.3 54.7 55.8 52.4 Ethylene glycol 5.4 6.8 4.8 5.0 5.5

Further additions of ethylene oxide and strong nitric acid can he made to provide even higher concentrations (e g 7092) EGMN EXAMPLES 9 11 Continuous preparation of EGMN A continuous process was employed to produce EGMN liquors. Three vessels were connected in series and comprised a mixing tank, a nitrator and a neutralizer. The vessels were equipped with mixing devices, cooling devices and inlet and outlet orifices. An acidic aqueous solution comprising from 26-33 parts by weight of ammonium nitrate, 46-52 parts by weight of strong 98% nitric acid and 15-25 parts by weight of water was prepared in the mixing tank. This solution was fed by pump into the nitrator where it was contacted with ethylene oxide vapor. The feed rates of the solution and the vapor were controlled so as to maintain a reaction temperature between about 30C. and about C. which range reduced the production of side products such as ethylene glycol or ethylene glycol dinitrate. The desired nitration product on a weight percent basis is 1-12% nitric acid, 18-25% ammonium nitrate, 10-15% water, 2-8% ethylene glycol and 30-60% EGMN. The crude product from the nitrator overflowed continuously into the neutralizer where a gas sparger dispersed ammonia gas uniformly into the stirred reaction mixture. pH was controlled in the range 6.2 to 6.5. In this stage an additional 2-15% by weight of ammonium nitrate was produced from the reaction 0 of ammonia gas with residual nitric acid present. The

effluent from the outlet of the neutralizer was the desired final product which normally contained from 40-60% by weight EGMN, 2-8% by weight of ethylene glycol, 2535% by weight of ammonium nitrate and 10-25% by weight of water. The following EGMN liquors were produced by the continuous process.

Example 9 10 ll Ammonium nitrate 27.5 29.2 25.9 Water 15.0 16.1 22.4 EGMN 53.6 49.4 46.8 Ethylene glycol 3.8 5.3 4.9

EXAMPLE l2 Sensitivity of Ethylene Glycol Mononitrate (EGMN) EXAMPLES 13-21 Preparation of PGMN and HCPN Batches of propylene glycol mononitrate and hydroxychloropropyl nitrate were made by a method similar to that of Example 2. It was found, however, that high initial concentrations of ammonium nitrate led to its crystallization as the reaction proceeded and that the presence of sodium nitrate caused a liquid-liquid phase separation during the reaction. Typically 50 g. of ammonium nitrate and 63 ml. of nitric acid served as a starting mixture. Propylene oxide or epichlorohydrin and 70% nitric acid were added through separate inlets at the same molar ratio until 16-30 mol of acid had been added followed by 5-17% excess of propylene oxide or epichlorohydrin. Additional ammonium nitrate can be added dissolved in the nitric acid to maintain a high nitrate concentration. Up to 470 g. of ammonium nitrate remained in solution. Neutralization of the excess acid with liquid ammonia led, in the case of the propylene glycol mononitrate synthesis, to a liquidliquid phase separation with a more concentrated solution of the desired product, PGMN, In the upper layer. It was found with both syntheses that saturation of the system with sodium nitrateor calcium nitrate led to a more efficient separation in which the layer having the major portion of mononitrate ester contained comparatively little water. This technique was therefore wellsuited to the aims of the present invention. The preferred compositions of the feeds to the reactor are compatible with the operation of the continuous process of Examples 9 l l Summarized are the analysis of representative batch reaction products:

[Tutti] pic with a No. 6 electric blasting cap. This represents an explosive with a controlled reduction in sensitivity when compared to a nitroglycerine gelatine of equiva lent strength Notes txttmples i3. I4 and were obtained by separation of the main liquor layer after neutralization with ammonia [Example 16 was obtained from Example [5 by saturation of the system with sodium nitrate and retention ofthe sensitiierrich layer, Examples I9 and 20 were obtained as the one-phase product of the reaction after neutralization with ammonia.

Example 2! was obtained from Example 20 by saturation 0| the system with sodium nitrate and retention ofthe SCHst- The preparation of compositions of hydroxyalkyl nitrate (HAN) which are analogous to the conventional high explosives based on nitroglycerine, ethylene glycol dinitrate or mixtures of these involves the isolation of substantially anhydrous HAN from aqueous liquors thereof. For illustrative purposes, this may be done by extraction of EGMN from reactor liquor with methylcne chloride, which is then stripped off in an evaporator unit.

EXAMPLE 22 Gelatinized explosive composition EGMN/EU Nitrocellulose (dynamite grade) Ammonium nitrate tt lendcil fines) 55.5 Sodium nitrate (Chilean) l6 0 Vegetable meal 0.5 Wood pulp (l5 sulphur 0.4 Lalciurn carbonate (chalkl 0.4

A very extractable. full-bodied explosive composition was obtained which detonated (l X 8 inch cartridge) when initiated either with a primer of 50% strength dyri unite or with high strength eiectric blasting cap at a \cioeity ol 2 57 km 'sec. The cartridge was not initiated While the toxicological properties of ethylene glycol mononitrate are not fully known it is reported to be much less toxic than nitroglycerinc. lt has a vapour pressure very similar to ethylene glycol dinitrate which is the volatile and predominant constituent of all the nitroglycerines of modern commerce. Nevertheless, in both controlled exposures and in extensive work periods with EGMN, none of the characteristic NG headaches caused by dinitrate vapours were experienced, Thus, an additional property of explosives made with EGMN is the elimination of the headache-producing characteristics of NG-explosives.

Nitroglycerine was found to have remarkable and unexpected solubility characteristics with respect to EGMN liquors When a nitroglycerine which has been made from a feedstock containing l5% glycerine and ethylene glycol was mixed with the EGMN liquor of Example l3, no phase-separation occurred at up to 12% NG, in spite of the fact that the system contained about l4% water and 24% dissolved saits. At higher levels of nitroglycerine, clean efficient separation into layers was obtained. with good extraction of EGMN Into the predominantly organic layerv Further dehydration of this layer could be accomplished by the addition of compounds immiscible with water Dinitrotoluene or molten trinitrotoluene were found to be effective extractants for the hydroxy alkyl nitrate constituents from reactor liquors EXAMPLE 23 27 Gelatinized explosive compositions Concentrated solutions of EGMN were prepared by mixxing together reactor liquors with explosive ingredients which promote phase separation as described heretofore Gelatin-type compositions were prepared from these solutions by techniques well known in the art with the results summariz ed below, the proportions shown being in percent by weight Example 23 Z4 2o 27 by eight ol 4% 77 77 7] his EGMN liquor (lit. 5! (Ex, h) (Ex. ('1) tl-Ix. ht {Ex hr i by eight \Il 52 2. 23 I IS 5 explosne separation (85 (i-NO ($5 (LNG) (K5 (i-Nfii {H5 (i-NG) (H5 (LNG) promoter (hr/I (U; "1' h ucighl of organic phase isolated 59.5 59.5 no.5 fall 7 lixplosne compositions Organic phase 31 ill] 30.1? 251) Bill! 250 D3. minute nitrocotton 5.95 U 5 (1. l 5 0.5 Ammonium nitrate fines 51.51) 55.8 4a.; 51o 51o Sodium nitrate ll) llti llM Zlll) IS U I) Wheat t'lour 1115 A 4 egetuhle meal 1 fill H) H) ill to \NtmLl pulp lllll llfl 1).] U 7 ll? Sulphur IIHU (L5 05 [L4 0.7 Calcium carbonate 0.5 (I5 (I 5 U4 (i 4 TNT lt'lakesl 4 5.0 A Detonations Paper cartridge I'W'XX" l /4" 8" ll WXR" li WXH" ll H'Xti" Primer No 6 EB cap No. 6 EB cap No. r1 EB cup No. l EB cap High strength cap Temperature 40F. 40F. 40F -ltlli 4Ul- \'cl of det tkmi'sec l FIR 11h Z 37 I (13 Ill Nilrit c lcr mixture ol cllitlene glycol and lii gi tcrine Example 23 had a mixed density of 1.47 g./cm and had a soft consistency which extruded easily and cleanly for cartridging. the composition was still soft were found to work more efficiently if a small amount of hydroxyethylcellulose of high molecular weight was added and swelled first.

(Contains about 26% hydroxychloropropyl nitrate and about (Contains about 25W propylene glycol mononitratc and about Detonation tests unconfined Polyethylene cartridge diameter Primer (pentolitc Results 2. water! i 1% water) 4 inches 4 inches bl] gr fill g. Detonuted Dctonated Liquor CltllCLnlhilCLl from intniple l? h mturution \\ith sodinm nitrate EXAMPLES 28 -29 Gelatin-type explosive compositions Gelatin-type explosives of a somewhat lower sensitiv ity were prepared from propylene glycol mononitrate and hydroxychloropropyl nitrate liquors. The lowwater concentrate liquors swelled nitrocellulose. but

EXAMPLES 3O -33 Gelatinized explosive compositions Sensitizcr liquors were prepared by admixture of the low-water liquors like Examples 16 and 21 with standard EGMN liquors like Examples 9 l l and saturating amounts of salt. For example. parts of PGMN liquor and 200 parts of EGMN liquor were mixxed with sodium nitrate; 209 parts of sensitizer-rich layer sepa rated which contained only i 1% water and l5% ammo nium nitrate.

The low water-levels attained in liquor concentrates were advantageous of the preparation of gelatinized compositions containing nitroglycerin. without need for addtional liquid-phaseseparation operations of the type described in Examples 23 27. These are illustrated in Examples 30 33 with compositions given in percent by weight.

Semi-gelatin types Gelatin types Ex. 30 Ex. 3] Ex. 32 Ex. 33

Liquor l l0 l" l5 Nitroglyce rine l0 l0 l5 l5 Nitrocotton 0.5 0.5 0.8 0.8 Ammonium nitrate (blended fines) 75 9 75.9 53.9 66.4 Sodium nitrate I20 Vegetable pulps 2.5 2.5 2.5 2.0 Sulphur 0.3 0.3 0.3 0.3 Stearic acid 0.5 (1.5 Chalk 0.3 0.3 0 5 0.5 Detonation tests (uneonfinedin 1%" diameter polyethylene cartridgcsl initiator cap No. 2 No. 4 No. 6 No. 4

Fill F/C EB F/C Velocity of detonation (km/sec.) 2.9 2.9 2.2 2.3

'EGMNJPGMN liquor concentrate described uhmc PGMN liquor. Example lo "PUMN liquor concentrated from Example l7 by saturation with sodium nitrate HCPN liquor. Example Zl EXAMPLE 34 Substantially dry, dynamite type explosive composition Low'nitroglycerinecontaining dynamite compositions typically employ about 9% nitroglycerine. A typical EGMN liquor used at about a level in place of nitroglycerine and in conjunction with usual oxygen-supplying salts and dopes formulated in dynamite would introduce 2 3% water and 8 ll% ethylene glycol mononitrate into the formulation. These water levels were deemed to be acceptable and no drying of an EGMN liquor was necessary before use in such a composition. A composition was made up having the formula:

EGMN liquor (Example 9) l8.0% Ammonium nitrate (fine) 63.3 Sodium nitrate (Chilean) 10.0 Vegetable meal 20 Wood pulp 2.0 Wheat flour 1.5 Tamarind flour 3.0 Calcium carbonate 0 ,2

The composition was of a damp, cohesive consistency typical of conventional dynamite and in a four inch diameter paper cartridge unconfined, this formulation gave a strong detonation at 70F. when initiated with a high-strength cap EXAMPLE 35 Substantially dry, dynamite type explosive compositions An explosive composition containing relatively large proportions of liquid hydroxyalkyl nitrate sensitizer,

thickened with nitrocellulose, and rendered rather dry in consistency by admixture with cellulosic pulp, is exemplified in the following formula:

Hydroxyalkyl nitrate liquor (Example 2ll 45.0 Hydroxyethyl cellulose 02 Nitrocotton 1.2 Sodium nitrate 4o.2 Ccllulosic pulps 7.0 Chalk 0,4 Detonation tests (unconfinedl Polyethylene cartridge diameter 3" Primer (pentolite) (10 g. Velocity of detonation 2.4

(km/sec.)

EXAMPLES 36 43 Dry blasting agent compositions Dry blasting agents normally employed in dry boreholes especially in open-pit mining and quarrying operations, are exemplified by the ammonium nitrate-fuel oil (ANFO) compositions. ANFO has been shown to be both economic and safe but suffers somewhat from an intrinsic insensitivity which requires substantial priming of a charge for initiation and propagation. It has now been found that the addition of hydroxyalkyl nitrate (HAN) liquor to typical AN FO compositions enhances their sensitivity. Advantage can also be taken of the solubility of nitroglycerine in HAN liquor to intro duce small proportions of NG into dry blasting agents for the manufacture of compositions of exceptional sensitivity. Because the NG is soluble and dissolved, it can be uniformly distributed throughout the dry compositions in a highly dilute form.

Detonation tests on the dry blasting agent formulations shown below were carried out by placing the explosive in a 4-inch diameter polyethylene bag on a steel plate supported on a lead bar of l X V4 inch cross section bent into the form of a circle. A strong detonation severely flattened this lead bar.

All the examples are demonstrably more sensitive than the control, a standard ammonium nitrate/fuel oil explosive prepared with the porous prills. Standard ANFO normally requires a No. 6 EB cap plus five No. 8 blasting caps for a strong detonation. The proportions shown are in per cent by weight.

- fontinued Example Control h r Nu h l li caps No K ltll caps What we claim is:

l. A substantially non-aqueous explosive composi tion having a water content of less than 3% by weight and having as a sensitizer at least one liquid hydroxyalkyl nitrate.

2. An explosive composition as claimed in claim 1 wherein the liquid hydroxyalkyl nitrate sensitizer is lected from ethylene glycol mononitratc, propylene glycol mononitrate. hydroxychloropropyl nitrate and mixtures thereof.

3. An explosive composition as claimed in claim 1 having an extrudable gelatinous consistency comprising essentially from 40 to 80% by weight of oxygensupplying salt. from I to 15% by weight of carbonaceous material, at least 5% by weight of liquid hydroxxyalkyl nitrate sensitizer and adjusted to a gelatinous consistency by the further incorporation of gelproducing liquid/thickener combination 4. An explosive composition as claimed in claim I having a tampable, cohesive consistency comprising can 1 il l l: l l H! l high strength clip 1 hlgh strength cu essentially from 5 to 40% by weight of liquid hydroxyalkyl nitrate sensitizer, from 40 to by weight of0xygen-supplying salt from I to l5% by Weight of carbonaceous material, up to 10% by weight of a gelextending liquid and a thickening additive S. An explosive composition as claimed in claim 1 having a dry blasting agent consistency comprising essentially from 65 to by weight of particulate ammonium nitrate, from 0.5 to 15% by weight of carbonaceous material and from 2 to 20% by weight of liquid hydroxyall-tyl nitrate sensitizer.

6. An explosive composition as claimed in claim 1 also containing at least one supplementary sensitizer material.

7. An explosive composition as claimed in claim 6 wherein the supplementary sensitizer material is selected from particulate metal. ethylene glycol dinitrate nitroglycerine, pentaerythritol tetranitrte, dinitrotoluene. alkylamine nitrate, alkanolamine nitrate, ammonium perchlorate and mixtures thereofv

Claims (7)

1. A SUBSTANTIALLY NON-AQUEOUS EXPLOSIVE COMPOSITION HAVING A WATER CONTENT OF LESS THAN 3% BY WEIGHT AND HAVING AS A SENSITIZER AT LEAST ONE LIQUID HYDROXYALKYL NITRATE.

2. An explosive composition as claimed in claim 1 wherein the liquid hydroxyalkyl nitrate sensitizer is selected from ethylene glycol mononitrate, propylene glycol mononitrate, hydroxychloropropyl nitrate and mixtures thereof.

3. An explosive composition as claimed in claim 1 having an extrudable gelatinous consistency comprising essentially from 40 to 80% by weight of oxygen-supplying salt, from 1 to 15% by weight of carbonaceous material, at least 5% by weight of liquid hydroxxyalkyl nitrate sensitizer and adjusted to a gelatinous consistency by the further incorporation of gel-producing liquid/thickener combination.

4. An explosive composition as claimed in claim 1 having a tampable, cohesive consistency comprising essentially from 5 to 40% by weight of liquid hydroxyalkyl nitrate sensitizer, from 40 to 90% by weight of oxygen-supplying salt, from 1 to 15% by weight of carbonaceous material, up to 10% by weight of a gel-extending liquid and a thickening additive.

5. An explosive composition as claimed in claim 1 having a Dry blasting agent consistency comprising essentially from 65 to 95% by weight of particulate ammonium nitrate, from 0.5 to 15% by weight of carbonaceous material and from 2 to 20% by weight of liquid hydroxyalkyl nitrate sensitizer.

6. An explosive composition as claimed in claim 1 also containing at least one supplementary sensitizer material.

7. An explosive composition as claimed in claim 6 wherein the supplementary sensitizer material is selected from particulate metal, ethylene glycol dinitrate, nitroglycerine, pentaerythritol tetranitrte, dinitrotoluene, alkylamine nitrate. alkanolamine nitrate, ammonium perchlorate and mixtures thereof.