JPS5842159B2 - Method for manufacturing hydrous explosives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a hydrous explosive which has a small diameter and can be detonated by a No. 6 detonator even at low temperatures in an open state.

Conventionally, two types of explosives containing nitroparaffins are known.

That is, one does not contain water, and the other contains water.

The significance of including water is that by dissolving the inorganic oxide salt in water, the explosive composition becomes a somewhat homogeneous system, increasing the explosive reactivity when it explodes, and as a result, an explosive with a high detonation velocity can be obtained. .

However, the inclusion of water has the negative effect that, on the one hand, water plays a role in reducing heat, and on the other hand, it causes problems in separation from nitroparaffins.

For water-free nitroparaffin explosives, see U.S. Pat. No. 3,338,165 and U.S. Pat. No. 3,37
They are described in many patent specifications such as US Pat. No. 7,217 and US Pat. No. 3,762,970, and various types are known, including those that are detonated by a detonator and those that are not detonated.

Regarding nitroparaffin explosives containing water,
U.S. Patent No. 3,419,444, U.S. Patent No. 3.5
No. 46,034, US Pat. No. 3,765,966, and US Pat. No. 3,985,593. There are few things that are explosive.

As an example of a detonator with detonating properties, the above-mentioned US Patent No. 3
, 765,966, U.S. Pat. No. 3,985,59
There are specifications such as No. 3, but in the case of U.S. Patent No. 3,985,593, perchlorate is mainly used as the inorganic oxide salt, and ammonium nitrate (hereinafter referred to as ammonium nitrate) in the present invention is Compared to the main composition, it is inferior in both performance (open state detonation, power) and price.

In addition, in the case of US Pat. No. 3,765,966, the composition is somewhat similar to that of the present invention, but the glass micro hollow spheres (generally particle size is 10 to 300μ) used as a component thereof are Since the surface of the particles is relatively smooth and well-shaped, it is difficult for the gelled product of tritroparaffin, which is a coexisting component, to adhere to it, and the gelled nitroparaffin once attached is easy to peel off from the glass micro hollow spheres. Because of this tendency, it is difficult to maintain an intimate mixture of the nitroparaffin gel and the glass microscopic hollow spheres.
The composition described in No. 966 was small in diameter and could not be detonated by a No. 6 detonator under harsh conditions of open and low temperatures.

The present invention provides a method for producing a water-containing explosive that can eliminate the drawbacks of the water-containing nitroparaffin explosive, and uses Shirasu micro hollow spheres and/or silica micro hollow spheres to produce a nitroparaffin explosive. Even if the content of nitroparaffin is small, it is possible to obtain a nitroparaffin-based hydrous explosive that can be detonated with a No. 6 detonator even in a small diameter open state at low temperatures. This manufacturing method enables continuous production and maintains explosive properties.

That is, the hydrous explosive composition targeted by the present invention is a)
Ammonium nitrate or ammonium nitrate and other inorganic oxide salts, a) sugars, c) water,
2) Water gelling agent, e) Nitroparaffin (1 or more carbon atoms)
3) and f) a composition consisting of a nitroparaffin gelling agent, further containing th) shirasu micro hollow spheres and/or silica micro hollow spheres.

The method for producing a hydrous explosive of the present invention involves adding nitroparaffin (carbon After adding and kneading a mixture obtained by mixing a nitroparaffin gelling agent to a mixture of several liters to 3) and Shirasu micro hollow spheres and/or silica micro hollow spheres and pre-disturbing, the mixture is further gelled with water. It is characterized by adding an agent and uniformly mixing and kneading it.

Next, the present invention will be specifically explained.

That is, the hydrous explosive targeted by the present invention has the following composition.

Ammonium nitrate or ammonium nitrate and other inorganic oxide salts (for example, sthorium nitrate, sl-lium perchlorate, etc.) are contained in an amount of 50 to 75% (by weight, the same applies hereinafter).

Examples of saccharides include monosaccharides such as pentose and hexose, oligosaccharides such as sucrose and maltose, and polysaccharides such as starch and cellulose, which are contained in an amount of 2 to 7%.

The water content is 5-20%, preferably 10-15%.

It is preferable that the nitroparaffin contains 5 to 40% of tromethane, nitroethane, or tritropropane, and for example, 7 to 20% of nitromethane.

Shirasu micro hollow spheres are obtained by burning shirasu, which is a type of volcanic ash, and the particle size thereof is usually 30 to 600 microns.

Silica minute hollow spheres are obtained by firing purified silica sand, and their particle size is usually relatively large, 100 to 1000 microns.

These microscopic hollow spheres may be used alone or in combination, and their content is 1 to 6%, preferably 2 to 4%.

In addition, these micro hollow spheres have irregularly shaped particles with rough surfaces, compared to the particles of glass micro hollow spheres, which have smooth and regular surfaces. The microscopic hollow spheres used have excellent adhesion to the gelled product of nitroparaffin, are able to maintain an intimately mixed state of the two components, and have the effect of easily entrapping air bubbles.

In addition, in order to improve the detonation properties of the hydrous explosive composition, it is necessary to use fine glass micro hollow spheres with an average particle size of several tens of microns. Micro hollow spheres or silica micro hollow spheres are several hundred μ
Even something as coarse as this has the characteristic of being able to make its detonation properties high enough.

As a gelling agent for 2I-lobalafuin, for example, nitrocellulose, ethylcellulose, or cellulose acetate tongue is used in an amount of 0.5 to 5%.

In addition, examples of water gelling agents include self-crosslinking guar gum (
For example, guar gum containing potassium pyroantimonate)
and various gums such as guagato and xanthus gum, starches and sodium dichromate.

0.1 to 3% of ammonium borate or the like in combination with a crosslinking agent or the like is used.

Next, the method for producing a hydrous explosive of the present invention will be explained in comparison with a conventional method.

The conventional method for producing hydrous explosives is method A (see Figure 1).
The method for producing the hydrous explosive of the present invention is referred to as Method B (see Figure 2).

Method A is as follows.

First, ethylene glycol is added to a water gelling agent to disperse the water gelling agent, and then water is added thereto to gel the water to form a gelled product.

Next, the water gelled product is mixed with ammonium nitrate or ammonium nitrate and other inorganic oxide salts (hereinafter simply referred to as inorganic oxide salts such as ammonium nitrate), and saccharides are further added to obtain an inorganic oxide salt mixture.

On the other hand, after adding and mixing Shirasu micro hollow spheres and/or silica micro hollow spheres (hereinafter simply referred to as micro hollow spheres) to nitroparaffin, a gelling agent for nitroparaffin is added and a nitroparaffin containing micro hollow spheres is mixed. Obtain a paraffin gel.

A hydrous explosive is obtained by adding this nitroparaffin gel to the above-mentioned unsupported oxidized salt mixture and kneading the mixture.

Since the viscosity of the water gelled product and the mixture of the water gelled product and an inorganic oxide salt such as ammonium nitrate is high, method A requires mixing of the water gelled product and an inorganic oxide salt such as ammonium nitrate, and the resulting inorganic oxide. In mixing the acid salt mixture and the nitroparaffin gelled product, it takes 2 minutes or more for sufficient mixing.

Therefore, method A is not suitable for continuous production, but is suitable for batch production.

Furthermore, since the nitroparaffin gel containing microscopic hollow spheres is added to the highly viscous inorganic oxide salt mixture, several minutes of kneading time is required to improve its dispersion.

Because the kneading is carried out for a relatively long time in such a high viscosity state, the nitroparaffin gel and the micro hollow spheres separate, thereby reducing the detonation properties of the resulting hydrous explosive.

On the other hand, method B of the present invention is as follows.

First, an inorganic oxide salt such as ammonium nitrate is dissolved or suspended in water to obtain a solution or suspension in which saccharides are added.

On the other hand, after microscopic hollow spheres are added to nitroparaffin and mixed, a gelling agent for nitroparaffin is added thereto and pre-kneaded to gel the nitroparaffin, thereby obtaining a mixture containing microscopic hollow spheres.

To this mixture is added a solution or suspension of the inorganic oxide salt such as ammonium nitrate, and while mixing, a water gelling agent is added and kneaded to obtain a hydrous explosive.

Note that the term "suspension" as used herein refers to a mixed liquid in which solids are dispersed and mixed in a liquid.

In this method B, gelation of water is performed in the final step.

Therefore, before this final step, the mixture of inorganic oxide salts such as ammonium nitrate and water is a solution or suspension with high fluidity, and is a gelling agent for nitroparaffins, micro hollow spheres, and nitroparaffins. When mixing and kneading a mixture consisting of the above-mentioned solution or suspension of an inorganic oxide salt such as ammonium nitrate with high fluidity, the two are sufficiently mixed due to the high fluidity, and the nitroparaffin The final step is reached without separation of the gelled product and the micro hollow spheres,
A water gelling agent is added and mixing and kneading is performed to obtain a hydrous explosive.

Even in this final mixing and kneading process, water does not rapidly gel, so the hydrous explosive can be sent to the next packaging process while still maintaining its fluidity.

In other words, in method A, the water gelling agent is added at the beginning of the entire manufacturing process, so gelation of water tends to occur at a relatively early stage because there are few ingredients other than water, but in method B, gelation of water tends to occur at a relatively early stage. Since the gelling agent for water is added after all compounded substances other than water have been blended, gelling of water does not proceed rapidly but slows down.

Herein lies one feature of the manufacturing method of the present invention.

One of the more important features is that we use micro hollow spheres with a rough particle surface that is different from glass micro hollow spheres, such as Shirasu micro hollow spheres and silica micro hollow spheres, so during the manufacturing process, nitroparaffin gelled products and It is possible to mix and knead while maintaining adhesion to the micro hollow spheres, suppress separation of both, and ultimately separation of nitroparaffin from the entire composition, and easily entrap air bubbles.

Furthermore, the purpose of using ethylene glycol in Method A is to improve the dispersibility of the gelling agent in water.

On the other hand, in method B, the water gelling agent is added in the final step in the presence of particles of inorganic oxide salts such as ammonium nitrate and other components, so the friction between the particles causes the water to gel. The gelling agent is characterized by being sufficiently well dispersed even without ethylene glycol.

In addition, according to Method B, the gelation of the entire hydrous explosive further progresses even after the packaging process and becomes a product.

As explained in detail above, in the production method (Method B) of the present invention, each mixture in the intermediate step or the final step maintains favorable fluidity, so mixing is easy and can be carried out in a short period of time (usually Since it can be sufficiently mixed and kneaded in less than 1 minute), it is particularly suitable for continuous production, and also has a favorable effect on the explosive performance of the resulting hydrous explosive.

Next, the present invention will be explained in detail with reference to Examples and Comparative Examples.

The manufacturing method for each side was the above-mentioned method A or method B.

In addition, in the explosive performance test, the detonation test was performed using a 0.1 m thick
Made of polyethylene film with a diameter of 25 mm and a length of 2
A 507iL7Il polyethylene tube was filled with 200.9 kg of a hydrous explosive composition sample, brought to a predetermined temperature, detonated using a No. 6 detonator on sand (in an open state), and observed whether or not it detonated. Ta.

Further, the detonation velocity was measured by the ion gap method at the same time as the above-mentioned detonation test.

Examples 1 to 2 and Comparative Examples 1 to 4 Hydrous explosive compositions having the respective formulations shown in Table 1 were prepared by the above method A- or B (however, Comparative Example 4 did not contain micro hollow spheres, so B The mixture was manufactured using the mixing and kneading time shown in Table 1 (method 1), filled into the above-mentioned specified polyethylene pipe, and subjected to an explosive performance test.

The results were as shown in Table 1.

From the results in Table 1, it can be seen that the hydrous explosives produced by the method of the present invention have detonator detonation properties even in the open state even at -5°C, as shown in Examples 1 and 2, and the conventional production method (Method A) was applied. It was shown that the low-temperature detonation properties were better than those of Comparative Examples 1 and 2, and that Method B had better continuous productivity than Method A.

On the other hand, as shown in Comparative Examples 3 and 4, conventional nitromethane-based hydrous explosives that do not contain microscopic hollow spheres, even when manufactured by method A or method B', have low detonation properties even at room temperature in an open state. (It would detonate if it was sealed inside an iron pipe.)

Examples 3 to 4 and Comparative Examples 5 to 6 To compare the adhesion (releasability) to nitroparaffin gel between the Shirasu micro hollow spheres or silica micro hollow spheres of the present invention and the conventional glass micro hollow spheres. As shown in Table 2, hydrous explosive compositions containing various microscopic hollow spheres were prepared using method B (however, in Comparative Examples 5 and 6, the types of microscopic hollow spheres were different as described above, so B'
The final step of the manufacturing process, which involves adding and kneading a water gelling agent, was carried out using a mixing and kneading time of 1 minute or 10 minutes.

These hydrous explosives were also subjected to explosive performance tests using the test method described above, and the results are shown in Table 2.

From the results in Table 2, it can be seen that the hydrous explosives manufactured by the method of the present invention using Shirasu micro hollow spheres or silica micro hollow spheres of Examples 3 to 4 have the detonation performance of Examples 1 to 4 even when mixed and kneaded for a long time. Similar to 2, low-temperature detonability was not lost.

However, in the case of Comparative Example 5, in which glass micro hollow spheres were mixed and kneaded for a long time of 10 minutes, the low-temperature detonation properties were found to be worse than in Comparative Example 6, which was mixed and kneaded for a short time of 1 minute. The results were shown.

The reason for this result is that the glass micro hollow spheres are in a close state with the nitroparaffin gelled product, but due to long-term mixing and kneading, they become separated from each other and dispersed in the composition. This is thought to be because air bubbles are lost during mixing and kneading.

The properties of such glass microscopic hollow spheres have been shown to easily affect the problem of performance deterioration during handling and storage of hydrous explosives containing them.

However, in the case of the shirasu micro hollow spheres or silica micro hollow spheres in the present invention, it can be easily inferred from the results of this example that the above-mentioned problems are unlikely to occur.

Examples 5 to 10 Hydrous explosive compositions having the respective formulations shown in Table 3 were manufactured by the method B above for the mixing and kneading times shown in Table 3, and explosive performance tests were conducted by the method already shown. .

The results were as shown in Table 3.

As can be seen from the results in Table 3, Examples 5 to 6, in which sodium nitrate was used in combination with ammonium nitrate, and Example 7, in which sodium perchlorate was used in combination, had explosive properties even at a low temperature of -10°C. ing.

In Example 8, the amount of nitromethane blended was lower than in the other examples, and the amount of Shirasu micro hollow spheres was increased, but even in this case, it detonated at 5°C and had sufficient low-temperature detonation properties. It was shown that

Example 9 is an example in which a mixture of nitromethane, nitroethane and nitropropane is used, and Example 10 is an example in which Shirasu micro hollow spheres and silica micro hollow spheres are used in combination, but in both cases, O' It was shown that the detonator can be detonated in the open state at low temperatures below Celsius.

As explained above in detail, the hydrous explosive produced by the method of the present invention uses shirasu micro hollow spheres and/or silica micro hollow spheres, which have coarser particles and are cheaper than conventional glass micro hollow spheres. As a result, these microscopic hollow spheres have a close relationship with the nitroparaffin gel, and their performance does not deteriorate even under harsh manufacturing, handling, or storage conditions. , which has detonating properties even in the open state, enables continuous production, and produces a hydrous explosive that has the above-mentioned excellent performance without impairing the closeness between the micro hollow spheres and the nitroparaffin gel. can do.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram for explaining the conventional manufacturing method (method A), and FIG. 2 is a process explanatory diagram for explaining the manufacturing method (method B) of the present invention.

Claims (1)

[Claims] 1 Add nitroparaffin (1 to 3 carbon atoms) and Shirasu micro hollows to a solution or suspension obtained by dissolving or suspending ammonium nitrate or ammonium nitrate and other inorganic oxide salts in water, and further dissolving or dispersing sugars. A mixture of spheres and/or silica micro hollow spheres and a nitroparaffin gelling agent is mixed and pre-kneaded, then a mixture is added and kneaded, and then a water gelling agent is further added and mixed uniformly. A method for producing a hydrous explosive characterized by kneading.