DK144372B - LIQUID OR HIGHLY SENSITIVITY OR HIGHLY SENSITIVITY - Google Patents

Description

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| É (i2) PRESENTATION DI) 144372B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 5754/70 (51) lnt.CI.3 C 06 B 29/00 (22) Filing date 12 Nov. 1970 (24) Race day Nov 12 1970 (41) Aim. available May 14, 1971 (44) Submitted Mar 1 1982 (86) International application # - (86) International filing day (85) Continuation day - (62) Master application no -

(30) Priority 15 «Nov. 1969, 87657¾ US

(71) Applicant IRECO CHEMICALS, Salt Lake City, US.

(72) Inventor Albert Gall Funk, US: Boyd LaMar Hansen, US: Melvin

Alonzo _Coo.k, US.

(74) Plenipotentiary Danish Patent Office ApS.

(54) Liquid or sludge burst = substance or explosive composition with high sensitivity.

The present invention relates to liquid or sludge-like explosives or high-sensitivity explosive compositions containing a perchlorate as an essential oxidant and an organic liquid.

From the specification of US Patent No. 3,096,223, sludge-like Φ explosives are known which consist of a mixture of sodium chlorate, ammonium perchlorate or potassium perchlorate with high content of high Γ explosives such as trinitrotoluene (TNT), about 8- The sensitivity of sludge-like explosives of this type is necessarily based on the relatively high content of V * * □ 2 144372 of high explosive substances, however, the use of high explosive substances presents disadvantages, as there is a risk associated with their handling. , and furthermore, they are expensive.

Further, from the specification of GB Patent No. 907,611, sludge-like explosive compositions containing sodium chlorate, ammonium nitrate beads, organic liquid fuel and water are known. The explosive compositions specifically mentioned in the aforementioned GB patent specification have a high content of sodium chlorate of at least 40% by weight. Sodium chlorate is an extremely dangerous oxidizing salt due to its sensitivity to friction and heat. The maximum liquid content (alcohol + water) of the specifically specified explosive compositions is 21.1% and this amount of liquid is insufficient to keep all the oxidation salt in solution at the application temperatures.

The object of the invention is to provide liquid or slurry explosives or explosives compositions with high sensitivity without content of high explosive as a sensitizer and without chlorate salt, and wherein all the oxidation salt remains in dissolved form in an aqueous solution containing a liquid organic fuel.

This is achieved with the explosive composition according to the invention, which is characterized in that it consists of a substantially oxygen-balanced liquid mass which is detonable in itself and that the organic liquid has a considerable calorific value, preferably of at least 3890 cal / g, which liquid contains the oxidizing agent in a dissolved state wherein a substantial amount of the oxidizing agent, preferably 20-60% by weight, is constituted by perchlorate, and wherein the oxidizing agent and liquid are selected so that the oxidizing agent remains dissolved in the liquid mass at the application temperature, and where the liquid mass contains much

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small gas bubbles and have a density of at least 1.0 g / cm.

Compared to the known explosive compositions, the explosive composition of the invention has the advantage that it does not contain high explosive substances such as TNT which are dangerous to handle and also expensive, and furthermore it does not contain chlorates which are very sensitive to friction and heat. In addition, the explosive composition of the invention has high sensitivity since all the oxidizing salt is present in dissolved form at the use temperature. The salt solution, of course, serves as a continuous liquid phase in a typical slurry. The influence of temperature on the sensitivity is illustrated by a typical explosive slurry composition having a critical diameter of 5.1 cm at 25 ° C which, when the temperature drops to 5 ° C, rises to at least 6.3 cm. In many and probably most known slurries a very significant change in critical diameter is usually found over a small temperature range. It is believed that this is in each case mainly because, while at higher temperatures, true solutions of oxidant, usually ammonium nitrate, are present, some of the oxidant salt will be separated from the solution at somewhat lower temperatures. The solubility of ammonium nitrate in water decreases very rapidly with decreasing temperature. This is to a different extent also the case with most other powerful oxidizing salts. In cases where there is a genuine solution of oxidant and fuel which is stable over a working temperature range and where the oxidant and fuel are thus in intimate contact, ie. truly in molecular contact with each other in the liquid regardless of temperature changes, the adverse effect of temperature on the sensitivity and critical diameter of the composition can either be completely eliminated or at least substantially reduced. Thus, one of the aspects of the present invention is the recognition of the importance of keeping the oxidant salts dissolved as well as ways of doing so in the temperature range that is most likely to occur in practice. It has also been found that, according to the invention, the sensitivity of an oxidizing agent solution, all else equal, can be significantly increased and maintained at an acceptable level over a reasonable temperature range by appropriate choice of solvent or solute, or a combination thereof, even when relatively poor fuels and oxidants are used.

It is desired that an efficient fuel and almost all the oxidizing agent remain in solution together and thus in molecular contact over the entire expected temperature range.

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The compositions of the invention are not substantially affected by normal temperature changes since the necessary molecular contact between fuel and oxidant is maintained. The oxidizing agents as well as the fuels must, of course, be carefully selected. By producing eutectic points for two or more salt-type oxidants selected by a selected group, according to the present invention, an even better solubility interval for the oxidant ingredients in the fuel solvent solution can be obtained, i.e. over a wider temperature range than is possible with a single salt. At the same time, it is possible to obtain the advantage of maximum molecular contact within the composition, due to the fact that most or almost all of the oxidizing agent and at least a considerable part of the fuel are in real solution with each other. In this way, a liquid which is detonable in itself is obtained.

The required amount of water can be reduced to or near a practical minimum. Sufficient solvent, water and other liquids are necessary to maintain a true solution at the application temperature. Water can go and often react with or form as a potent component in the presence of comminuted aluminum or other metals such as magnesium, silicon or boron. This occurs, provided an appropriate reaction temperature and other conditions can be obtained and maintained, see Cook, "The Science of High Explosives," ACS Monograph No. 139 (1958), page 304.

Another aspect of the present invention is that it facilitates the use of slurries with higher than normal weights. Where liquid or slurry explosives can be used and where they can be detonated at high weights, perchlorates as oxidizing agents have particular advantages. For use in the molecular type of sensitive slurries, as mentioned above, they have excellent properties.

The invention is further illustrated by the following examples.

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Example 1

A basic explosive solution is prepared by combining 52 wt% sodium perchlorate, 18.5 wt% water, 5.5 wt% sodium nitrate and 24 wt% ethylene glycol. This composition has a relatively high density of 1.58 g / cm. This is an advantage if you want a given volume to contain a maximum amount of weight explosive and thus maximum energy. Of course, the density can be reduced, and the composition can be made more sensitive by aerating with air or other gas in fine and well-distributed bubbles. This particular composition consisting of a liquid containing no suspended solids is not cap-sensitive at this density, but is in itself fully detonable.

It has a critical diameter at 25 ° C of 5.1 cm, which at 5 ° C increases to 6.4 cm. It turns out that one can initiate a detonation in the same solution by suspending significant amounts of a particulate self-acting explosive therein. 60 parts by weight of the above solution are mixed with e.g. 40 parts by weight of particulate pentaerythritol tetranitrate (PETN), adding, based on the total weight of the mixture, a little guar gum (0.2% by weight) to thicken the solution so that the suspended PETN particles are not precipitated by gravity. . This slurry mixture has a density of 1.78 g / cm. It is cap-sensitive in relatively small quantities and in a non-closed column diameter of 1.3 cm (paper tube). It is initiated at variable temperatures in the range of 40 ° C and as far as -30 ° C using a No. 6 safety cap.

Example 2

Another example of a slurry prepared according to the above principles contains 90% by weight of the solution described in Example 1, i.e. a solution consisting of sodium perchlorate, water, sodium nitrate and ethylene glycol. To this solution is added 8% by weight of finely divided aluminum and 2 parts of even finer aluminum. The resulting slurry has a viscous consistency which is obtained by the addition of a thickening guar gum in amounts of 0.2% by weight and using 0.1% by weight of a cross-linking agent HBO 3. The composition has a density of 1.43 g / cm 2. This density indicates that substantial amounts of air in the form of fine bubbles are likely to be entrained. The composition is cap-sensitive to a diameter of 0.95 cm. It is initiated down to a temperature of 0 ° C by means of a No. 6 cap. At a diameter of 1.3 cm, it is initiated with a corresponding catch cap down to -15 ° C. It detonates at -30 ° C to a diameter of 2.5 cm using 40 g of a 50/50 pentolite initiator.

Comparing the detonation rates is interesting. The liquid mixture as such has a detonation rate of 2300 m / sec, whereas the same mixture with added aluminum has a detonation rate of 5300 m / sec.

A non-contained slurry consisting of 60% of the liquids mentioned in Examples 1 and 2 in which 40% PETN is suspended does not detonate upon impact with a 30.06 rifle ball. However, the aluminum-containing mixture mentioned in Example 2 detonates upon impact with such a rifle ball. The solution itself, without the content of PETN and aluminum, is found to be stable up to 300 ° C by differential thermal analysis.

It shows exothermic reaction at 170 ° C with the addition of PETN and explodes spontaneously at 178 ° C. The aluminum mixture is stable up to 265 ° C.

Example 3

Another composition is prepared from 31.2% by weight sodium perchlorate, 11.1% by weight water, 3.3% by weight sodium nitrate and 14.4% by weight ethylene glycol as the liquid solvent and 0.1% by weight. % guar-v rubber thickening agent, as well as 40% by weight of particulate PETN supplied by a Swedish supplier. The solution without PETN content is explosive in itself. This slurry, incl. PETN, has a calculated energy Q of 1085 cal / g and a density of 1.78 g / cm. The PETN used here has a particle size of approx. 90% between -35 and +100 mesh. Attempts to prepare the same formulation but with a finer PETN, of which 40% would pass a 325 mesh sieve, failed, evidently because the mixture became too viscous and became a semi-gel at -40 ° C. The solution itself requires an initiator, more powerful than the No. 6 cap, to produce detonation in a 7.5 cm diameter column at 30 ° C.

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Under certain conditions, explosives other than PETN may be used, such as RDX or TNT. In experiments, however, finely divided RDX appears less satisfactory than PETN at very low temperatures. One must expect that TNT, which is less sensitive, would function even less satisfactorily.

Example 4

Another composition is made up of 22 wt% sodium perchlorate, 17 wt% water, 3 wt sodium nitrate, 8 wt% ethylene glycol, all in solution and then to this mixture 0.2 wt% guar. rubber thickener and 50% by weight of finely divided PETN.

At 20 ° C in a 1.3 cm column, this slurry can neither be detonated by means of No. 6 or No. 8 prison caps. Also, in a 2.5 cm column, it cannot be detonated by means of a No. 6 cap, whereas it detonates satisfactorily by using a No. 8 cap. The explosion creates a significant hole in a 1.3 cm steel plate. This slurry has a density of 1.77 g / cirr and is extremely viscous at 20 ° C.

Example 5

Using 60% by weight of the liquid composition of Example 1 with an oxygen balance of -1.3 and 40% by weight of finely ground PETN (about 40% passing through a 325 mesh Tyler screen), the resulting composition becomes sufficiently mobile to that it can flow slowly, ie that it can be pushed out of a tube, but it is almost too dry to be called a slurry at 20 ° C. At -40 ° C it is a solid. In a 0.95 cm column, it detonates using a No. 6 cap. When using 50% by weight of the same liquid and 50% by weight of the same PETN, the mixture is too dry to be called a slurry. A mixture of 65% of the solution and 35% of finely divided PETN is a little more thin-liquid than a 60:40 mixture, but is still quite kit-like in consistency. It has a density of 1.81 g / cm3. This PETN contains 40% particles sufficiently small to pass a 325 mesh Tyler screen. The 65:35 mixture detonates at -25 ° C at a diameter of 1.3 cm. By adding 5% aluminum in a grade used to make the paint, the mixture becomes so dry that it will not flow and it does not detonate using 144 caps. This illustrates that compositions in which the oxidant and fuel are completely or almost completely dissolved may be more sensitive than more dry mixtures. Usually, it is easier to bring more dry slurries to detonation than wet slurries.

Example 6

A composition of the following ingredients is prepared:

19% by weight sodium perchlorate

Water 15.0% by weight

Sodium nitrate 2.6% by weight

Ethylene glycol 3.4% by weight

Boric acid 0.05% by weight

Guar rubber 0.2% by weight

Finely divided aluminum 10.0% by weight PETN, finely ground 50.0% by weight o

This composition is too dry at 20 ° C to be called a slurry. It has a density of 1.82 g / cm at 20 ° C and detonates using a No. 6 cap in a 1.3 cm column, creating a hole in a 1.3 cm steel plate. It also detonates at 20 ° C in a 0.6 cm column using a corresponding No. 6 catch cap. The PETN used here is a medium ground product, of which 40% passes a 325 mesh screen.

Example 7

Another composition is prepared consisting of 33.3 wt% sodium perchlorate, 3.5 wt% sodium nitrate, 11.8 wt% water, 15.4 wt% ethylene glycol, 1 wt% guar gum thickener and 33 wt% fine and 2 wt% ultrafine aluminum as described in Example 2. This blend with an oxygen balance of -33.4% has a density of 1.65 g / cm and a detonation rate of 5390 m / sec.

Example 8

A second composition is prepared by a solution containing 47 parts by weight of sodium perchlorate, 5 parts by weight of sodium nitrate, 24 parts by weight of water and 21 parts by weight of ethylene glycol. To this solution is added 1 part of guar-rubber thickener and small amounts of gas-producing agents to aerate the slurry and reduce its density. The properties of the initial solution and of the solution after thickening and aeration are compared in the following table:

Solution with thickening λ i. ·. detergent and gas

Solution alone producing Jaier Density (g / cm 2) 1.54 1.25

Critical diameter (cm) 7.5 (minimum) 1.9

Detonation rate (m / sec) <2500 4800

Minimum initiates 30 g of pentolite # 6 cap

Although the foregoing examples deal mainly with explosives based on sodium perchlorate and sodium nitrate, ie. that sodium perchlorate constitutes the majority of the oxidizing agents used in the solution, this may be replaced in whole or in part by other perchlorates and nitrates.

Calcium nitrate, although in most cases less sensitive than the perchlorates, is particularly desirable as an ingredient in liquid explosives containing methanol. Calcium nitrate is readily soluble even at low temperatures in water, in methanol, in ethanol and in ethylene glycol. Calcium nitrate alone or in combination with sodium perchlorate has a low eutectic solubility point. In amounts as large as 70 to 75% of the total solution, the commercial grade calcium nitrate, containing 14 to 16% crystal water and usually a few% ammonium nitrate, has better (i.e., lower) excretion points than more dilute solutions of ammonium nitrate combined with sodium nitrate. See U.S.A. Patent No. 3,249,476. Data for this is given in Table 1.

Separation Weight - AN SN CN1 H20 EG Methanol Point Fill a. - - 75 - - 25 10 ° C 1.48

b. - - 75 10 - 15 -15 ° C

c. - - 70 - 10 15 10 ° C 1.57 d. - - 70 5 10 15 0 to -15 ° C -

e. 40 15 - 22 10 - 13 ° C

CN = calcium nitrate containing 5% by weight ammonium nitrate (AN and 16% crystal water).

ίο 144372

It is seen that calcium nitrate has desirable properties where it is desired to keep the oxidant dissolved (low excretion point), as here in the present invention.

Calcium perchlorate as an oxidizing agent or as a part thereof, and methanol or ethanol as a liquid fuel or as part thereof is distinguished by being both easily soluble in water and having good reactivity.

From the foregoing, it appears that a preferred explosive composition contains both fuel and oxidant in the solution, and that preferably all or substantially all oxidant is present in dissolved form. This component consists of as little as 20 to approx. as much as 60% by weight of oxidizing agent and preferably contains at least one perchlorate selected from a group consisting of ammonium perchlorate, alkali metal perchlorates and alkaline earth metal perchlorates. The perchlorate is the major oxidizing component, but is combined with a minor amount of at least one other strong oxidizing salt, preferably a nitrate selected from a group consisting of ammonium, alkali metal and alkaline earth metal nitrates. The salts should be selected so as to obtain a low eutectic solubility or excretion point so that they do not salt out the composition to a greater extent at the application temperature.

The liquid can contain 0 to 25% water and 5 to 30% fuel. At least part of the fuel must be water soluble. Ethyl glycol is usually preferred, but this can sometimes be replaced or supplemented with one of the simple alcohols. For the preparation of the explosive solution itself, a combination of approx. 0 to 20% water and a little more glycol or another organic solvent, e.g.

15 to 25%, particularly suitable. The organic solvent of choice must at least have a reasonably good calorific value, 3890 kcal / kg or higher. Diethylene glycol has a calorific value of approx. 4220 kcal / kg, methyl alcohol approx. 5270 kcal / kg and ethanol approx. 7550 kcal / kg, but the glycol is usually preferred in the present invention.

11 U4372

To maintain the integrity of the liquid, it is preferably thickened at least moderately by the addition of a small amount of a thickening agent. Guar gum in amounts of 0.10 to 1.0% by weight is particularly suitable. Starch can be used in larger quantities. Cellulose gums and derivatives thereof are useful in certain cases, such as methyl cellulose or hydroxyethyl cellulose. The rubber or starch is most often crosslinked by means such as borax or an alkali metal dichromate. Cross-linking not only protects against significant water penetration from external sources, but also helps to prevent the suspension of suspended fuel or self-acting explosive particles. It also enables the liquid phase to capture and retain very small air bubbles or bubbles of other gases, which is necessary to increase sensitivity. Air or other gases may be introduced by mixing or whipping into the thickened liquid itself or by stirring particulate solids in the liquid medium. Particulates of fuels and / or self-igniting explosives such as aluminum and / or particulate PETN, RDX, TNT and others can be added. The liquid mass itself is a potential explosive and is strongly oxygen balanced, even without the content of these particulate fuels and self-acting explosives.

In this regard, it differs substantially from prior art explosive slurries.

When using particulate non-explosive fuels, aluminum, sulfur and carbonaceous solids such as ground coal or gilsonite are preferred. Preferred self-acting explosives are PETN, RDX, Composition B, EDNA (ethylene diamine dinitrate) or TNT. These explosives should be selected and used in amounts that provide the desired sensitivity and help maintain the oxygen balance within reasonable limits and in each case between -50 and + 10%. For finely divided aluminum, amounts of up to 45% by weight of the total composition can be used. Where maximum burst force is required, it is preferable to use amounts from 20 to 40%. Part of this aluminum may be the fine flake aluminum of the quality used in the manufacture of paints; amounts in the range of 1-2% by weight of the latter component help to increase the sensitivity.

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Sensitive self-acting explosives such as PETN can be used in amounts up to 65% by weight of the total weight of the slurry. Of course, mixtures of PETN, RDX, Composition B, TNT and aluminum can be used or two or more of these substances. As the liquid phase itself is well oxygen balanced, the particulate materials must contain at least a portion of their own oxygen demand (as for self-acting explosives) or be water-responsive (as is the case with aluminum under favorable conditions when water is present ), or there must be some solid oxidant present in the particulate or suspended phase. This may be part of the primary oxidant (perchlorate) precipitated by the liquid phase or added separately, or it may be a separate or different oxidizing salt, such as e.g. AN, SN or calcium nitrate added separately. As already mentioned, smaller amounts of one or more of these salts can be extremely useful because they reduce the excretion point.

The compositions encompassed by the present invention are extremely versatile. They can be "tailored" to both the desired sensitivity and the desired explosive power by appropriately selecting component types and quantities. The liquid components, which contain large amounts of dissolved sodium perchlorate or other perchlorates and large amounts of ethylene glycol or other dissolved organic fuels which are molecularly close together, are inherently quite sensitive. By adding significant amounts of finely ground self-igniting explosives of the more sensitive type, which itself has a reasonably good oxygen balance, such as PETN, explosives with even higher sensitivity are obtained. These can carry on a detonation wave in a very small diameter column, such as in a column with a diameter as small or medium in diameter as 1.1 cm or less.

If such highly sensitive explosives are not required, the content of self-acting explosives such as PETN can be reduced or eliminated. Alternatively, this particular self-acting explosive may be replaced in whole or in part by one or more of the other self-acting explosives mentioned above and / or with aluminum powder.

In many cases, the addition of extremely finely divided aluminum, especially the flaked quality used in the manufacture of paints, will be

Claims (2)

144372 13 desirable because of its high burn and energy value. It contributes significantly to the generation of a high sensitivity, even in well-balanced liquid compositions. It is also desirable because of the mechanical handling properties it imparts to the composition. It acts as a lubricant during the flow of the composition through pipes and openings and when distributed through valves, pumps, hoses and other flow assemblies. Two other examples should be mentioned. The first contains 73.5% calcium perchlorate and 26.5% methanol. This solution itself has a weight density of 1.54 g / cm and is detonated in a column of 1.9 cm diameter by means of a 9-gram pentolite starter. The second composition contains 60% lithium perchlorate and 40% formamide. 3 This solution itself has a density of 1.56 g / cm and is detonated in a column of 2.5 cm diameter by means of a 9-gram pentolite starter. Claims. A high sensitivity liquid or slurry explosive or explosive composition containing a perchlorate as an essential oxidizing agent and an organic liquid, characterized in that the composition consists of a substantially oxygen-balanced liquid mass which is detonable in itself, and that the organic liquid has a significant calorific value, preferably of at least 3890 cal / g, which liquid contains the dissolved oxidant, wherein a substantial amount of the oxidant, preferably 20-60% by weight, is perchlorate, and thus the oxidant and liquid are selected that the oxidizing agent remains substantially dissolved in the liquid mass at the use temperature and wherein the liquid mass contains very small gas bubbles and has a density of at least 1.0 g / cm. Composition according to claim 1, characterized in that it also contains small amounts of an inorganic nitrate oxidizing salt to reduce the crystallization or excretion point of the liquid solution.