DE1288544B - Procedure to increase safety when shooting in coal mining - Google Patents

Description

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When shooting in coal mining must be eliminated according to the present invention by other special emphasis on security against one who is charged for the reception of the explosive charges

Firedamp ignitions are placed; furthermore, correct drill holes with foam or a foam die must be used Dust development, especially from health-like mass.

harmful dust, kept within reasonable limits 5 The foam or foam-like mass consists will. According to the invention, these sources of danger can be derived from a foaming agent, water by choosing a certain type of explosives and air that is free of mine gas and which goes beyond the compressed air network switch off; on the other hand, however, plays can be taken. The air can be partial or also the way of the technical execution, completely by gaseous carbonic acid and / or So the use of explosives, the shooting io inert gases are replaced. This will make the security work plays an important role in increasing safety against firing of mine gas and coal dust Ness. increased even more.

It has already been proposed that in a foaming agent within the meaning of the invention, for. B. borehole located explosive cartridges in an anion-active, cation-active and non-ionic water-containing, plastic, gelatinous mass embed 15 soaps and detergent substances as well as sapomins and this gelatinous mass at the same time as and protein body. Inorganic foam pattern trimming of the borehole can also be used. It was ner, z. B. from colloidal aluminum oxide and aliso proceeded that the borehole was first filled with the phatic carboxylic acids or phosphoric acids and paste and then the explosives - their salts can be used. Solfo cartridges were also pressed into the paste. This aonation products of mineral oils and alcohols process has the disadvantage that when pressing in and horse chestnut extracts are suitable as foam of the cartridges in the drill hole filled with the paste. Such foams also have a more or less large amount of paste between the advantage that they are not harmful to health,
see the cartridge heads come to rest, whereby it is advantageous to stabilize the foam by suitable foam stabilizers, known for proper detonation of the explosives, which are no longer added to the foam column within a borehole charge. As is guaranteed; this has undesired failures. Examples of foam stabilizers are: or deflagrations result. For this reason, condensation products of fatty acids with alkylol have not been used. amines, polyacrylic acids, urea, thiourea

Another well-known method assumes 30 or guanidine.

the explosive cartridges, especially when shooting. The water present in the foam carries

in the coal, surrounded by water in the borehole, significantly contributes to the efficiency of the dust

while at the same time increasing the amount of fighting coal to be blasted. It is, in contrast to the

for the purpose of binding dust with water under high pressure water in the impact impregnation process and the

is soaked. With this so-called shock paste, it is already very finely distributed and can be used in

However, soaking processes are only effective immediately if this very fine, active distribution is good

results are achieved when it is guaranteed that one will be. In the case of the previously known ones

water-tight closure of the borehole present procedure, however, it must first be atomized in order to

is and that the water cannot be divided or effective.

Fissures that may go through the borehole, 40 The introduction of the foam into a borehole

can leak. In the event of a seepage, it is best to do this in such a way that the foam, the

of the water from the borehole, it can then be poured into a suitable container on site

come that cartridges are produced freely without water protection in components, with the help of a

the borehole come to rest and thus into a thin-walled, non-sparking

can detonate dangerously. Another 45 of the pipe is inserted into the borehole. That

The disadvantage of this method is that only the hose or pipe end is first in the

a limited number of shots - up to three borehole depths if the foam is off the proportioner

in one ignition cycle - are dispensed from being filled in at the same time, and then slowly during

may, thereby withdrawing the procedure in the application of filling the foam until the

is limited, and that the procedure cumbersome 50 borehole filled with foam along its entire length

and is time consuming. is. With this procedure there is the possibility

It is also known to drill holes before the speed that the foam in crevices and crevices that the

Dismiss the shots to fill with gases. To enforce this borehole, can penetrate without

Any methane air that may be present should be the sufficiently stable foam from the borehole

Mixture can be removed from the boreholes. The 55 through, seepage is lost. In the borehole, for example

This method has the disadvantage that the mine gas is not con-located by the

can troll whether the boreholes completely displaced with "foam.

the gas are filled, as this is often present in the foam-filled borehole

Reefs, crevices or crevices can escape, so that thereupon the explosive cartridges with the ramrod

in such cases not a complete filling of the 60 pressed, with a corresponding amount of

Boreholes can be made with the gas. Furthermore, foam material is displaced. Now it is

This method is because of the difficult hand-held explosives charge in the borehole of one of the

Handling of the gases is cumbersome and time-consuming. A detonation unresponsive neutral medium

With this method, dust control can protectively surround. The remaining foam layer

cannot be reached at all. 65 forms between the explosive charge and the borehole

These mentioned safety disadvantages of the mouth have a trim that has a sufficient

previously known method for increasing the safe closure of the borehole guaranteed. Come too

When blasting in hard coal mining, the cartridges with their

Heads close together so that practically no foam remains between the cartridge heads and thus a complete detonation of the borehole charge is possible.

The method is also suitable when using cartridges in hose loads. These manufacture Hose charges can also be easily introduced into drill holes filled with foam. at Boreholes that are filled with the pastes known so far, on the other hand, is a proper filling with hose cartridges, due to the high friction, not possible.

The advantages of the new method over previously known similar methods consist in the inevitably increase the fire weather security, in the simplicity of the application and in the high efficiency in dust control. In addition, any number of shots can be shot in one Ignition cycle can be dismissed, while with impregnation shooting a maximum of three shots in one Ignition gear are permitted. Furthermore, it is unnecessary, as a result of the application of the above Process-forming foam plug in front of the boreholes that contain the explosive charge Previously common stocking with water cartridges.

The following examples show the effectiveness and the increase in firedamp safety described by the method according to the invention on the basis of tests on the test bench.

example 1

A water-containing foam with a density of 0.032 g / cm ^{3 was} produced from a foaming agent consisting of a mixture of different soaps. This foam could be kept for more than 50 minutes at temperatures of + 50 ° C.

A round mortar (borehole 55 x 600 mm) was filled with the foam. Then there were five cartridges a weather explosive of class I with the ramrod one after the other into the borehole to one Charging station introduced. The weather explosive had the following composition:

29.0 percent by weight nitroglycerin, nitroglycol

in a weight ratio of 60:40,

0.7 percent by weight nitrocellulose,
26.8 percent by weight ammonium nitrate,

3.0 percent by weight calcium nitrate,
40.0 percent by weight sodium chloride,

0.5 weight percent wood flour.

The mortar was then brought up to the front of a firedamp chamber. The ignition took place from the depth of the borehole. In ten identical attempts, the was not ignited Firedamp mixture. If, on the other hand, the column of explosives was put into the mortar without foam, so a firedamp ignition was carried out each time under otherwise identical test conditions in ten tests.

Example 2

In the same round mortar as in Example 1, a cartridge of a rock explosive with a Diameter of 25 mm axially centered 300 mm from the borehole mouth. The rock explosive had the following composition:

58.0 percent by weight NH ₄ NO ₃ ,
11.0 percent by weight NaNO ₃ ,
21.0 percent by weight dinitroglycol,
1.0 percent by weight nitrocellulose,
5.2 percent by weight dinitrotoluene,
3.8 weight percent trinitrotoluene.

If the hole in the mortar was filled with foam, none of the tests was carried out Firedamp ignition. If, on the other hand, there was no foam in the borehole, one was carried out for each experiment Firedamp ignition.

Claims (4)

Patent claims: 1. Method for increasing firedamp protection by displacing the in the boreholes containing gases and to improve dust control when shooting in coal mining, characterized in that one for the recording of the explosive charges determined boreholes with foam, the a foaming agent, water and gas, or a corresponding foam-like mass fills. 2. The method according to claim 1, characterized in that the foam with the help known foam stabilizers stabilized. 3. The method according to claim 1 and 2, characterized in that the gas used for foam production methane-free air used. 4. The method according to claim 1 and 2, characterized in that the gas used for foam production Carbon dioxide and / or inert gases are used.