Detonator-sensitive assembled booster charges for use in blasting engineering and the use thereof

Abstract

This invention relates to detonator-sensitive assembled booster charges for use in blasting engineering. The booster charge comprises nitroalkane and a cavity-forming agent.

Claims

1. A detonator-sensitive booster charge for use in blasting engineering comprising a mixture including a nitromethane and a cavity-forming means, wherein the cavity-forming means is configured as a hollow glass microsphere, and fumed silica, as well as a receptacle for an ignition device, wherein the booster charge is configured so as to be waterproof and temperature-resistant and comprises a concave curvature arranged on an opposite side of the receptacle for the ignition device.

2. The detonator-sensitive booster charge according to claim 1, wherein the booster charge is made of a liquid-impermeable material.

3. The detonator-sensitive booster charge according to claim 1, wherein the concave curvature comprises a metallic coating.

4. The detonator-sensitive booster charge according to claim 1, wherein the ignition device comprises a blasting cap, a detonating cord or a non-electric detonator.

5. The detonator-sensitive booster charge according to claim 1, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 20-200 m.

6. The detonator-sensitive booster charge according to claim 1, wherein the mixture comprises 1.5-10 weight % fumed silica, 0.2-10 weight % hollow glass microspheres and 85-98.3 weight % nitromethane.

7. The detonator-sensitive booster charge according to claim 1, further comprising an oxygen-containing compound selected from the nitrates group.

8. The detonator-sensitive booster charge according to claim 5, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 40-150 m.

9. The detonator-sensitive booster charge according to claim 5, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 80-120 m.

10. The detonator-sensitive booster charge according to claim 6, wherein the mixture exhibits 3-8 weight % fumed silica, 0.5-5 weight % hollow glass microspheres, and 85-95 weight % nitromethane.

11. The detonator-sensitive booster charge according to claim 10, wherein the mixture exhibits 5-7 weight % fumed silica, 0.8-2 weight % hollow glass microspheres, and 91-93 weight % nitromethane.

12. A detonator-sensitive booster charge for use in blasting engineering comprising; a mixture and a receptacle for an ignition device, wherein the mixture comprises 85%-98.3% by weight nitromethane, 1.5%-10% by weight fumed silica, and 0.2%-10% by weight a cavity-forming means wherein the cavity-forming means comprises hollow glass microspheres, and the booster charge is configured so as to be waterproof and temperature-resistant.

13. The detonator-sensitive booster charge according to claim 12, wherein the booster charge is made of a liquid-impermeable material.

14. The detonator-sensitive booster charge according to claim 12, wherein the booster charge comprises a concave curvature arranged on an opposite side of the receptacle for the ignition device.

15. The detonator-sensitive booster charge according to claim 14, wherein the concave curvature comprises a metallic coating.

16. The detonator-sensitive booster charge according to claim 12, wherein the ignition device comprises a blasting cap, a detonating cord or a non-electric detonator.

17. The detonator-sensitive booster charge according to claim 12, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 20-200 m.

18. The detonator-sensitive booster charge according to claim 12, wherein the mixture comprises 92.5% by weight nitromethane 6.5% by weight fumed silica, and 1% by weight hollow glass microspheres having a grain size of substantially 100 m.

19. The detonator-sensitive booster charge according to claim 12, further comprising an oxygen-containing compound selected from the nitrates group.

20. The detonator-sensitive booster charge according to claim 17, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 40-150 m.

21. The detonator-sensitive booster charge according to claim 17, wherein the cavity-forming means is configured as a hollow glass microsphere with a grain size of 80-120 m.

22. The detonator-sensitive booster charge according to claim 12, wherein the mixture exhibits 3-8 weight % fumed silica, 0.5-5 weight % hollow glass microspheres, and 85-95 weight % nitromethane.

23. The detonator-sensitive booster charge according to claim 22, wherein the mixture exhibits 5-7 weight % fumed silica, 0.8-2 weight % hollow glass microspheres, and 91-93 weight % nitromethane.

24. A detonator-sensitive booster charge for use in blasting engineering comprising; a mixture and a receptacle for an ignition device, wherein the mixture comprises 92.5% by weight nitromethane, 6.5% by weight fumed silica, and 1% by weight a cavity-forming means wherein the cavity-forming means comprises hollow glass microspheres having a grain size of substantially 100 m, and the booster charge is configured so as to be waterproof and temperature-resistant and comprises a concave curvature arranged on an opposite side of the receptacle from the ignition device.

Description

(1) FIG. 1 is a drawing of a non-limiting example of a detonator-sensitive booster charge as herein disclosed.

(2) The inventive detonator-sensitive booster charges are used to initiate non-detonator-sensitive commercial explosives, preferentially in boreholes on the surface and below ground, to initiate larger amplifier charges and for direct use for special blasting (avalanches, ice etc.). In particular, the inventive detonator-sensitive booster charges are used for the initiation of explosives in mining applications and tunnel construction.

(3) In doing so the inventive detonator-sensitive booster charges exhibit the following advantages:

(4) Detonation velocities of ca. 6000 m/s are achieved with the inventive detonator-sensitive booster charges, allowing the detonation of non-detonator-sensitive explosives. Moreover, no nitroaromatics, which are suspected to be carcinogenic, and no nitroesters, which are physiologically problematic due to possible vasodilation, are formed when the detonator-sensitive booster charges are used. Health problems among users can thus be avoided. In addition, the inventively preferred nitroalkane nitromethane is an inexpensive product that, due to the gas-phase nitration of propane, is available for the long termeven when recycled military explosives become scarce.

(5) Nitromethane is also not a classic explosive, which makes transport and storage inexpensive, and is of storage class 3 (flammable liquids). In addition, nitromethane has low toxicity: LD50 oral rat: 940 mg/kg, WHC 2.

(6) It is also advantageous that, in the event of damage, the inventive detonator-sensitive booster charges deactivate themselves by complete volatilization of the nitromethane into the air.

(7) The inventive detonator-sensitive booster charges are designed to be absolutely waterproof and temperature-resistant. There is no exudation of fluids. Thus, because there are no chemical reactions between the mixture components, the inventive detonator-sensitive booster charges in a mixture with Aerosil and GMBs have a practically unlimited shelf life.

(8) Moreover, the manufacturing of the inventive detonator-sensitive booster charges invention does not require dangerous melting processes. In addition, no long waiting period is necessary after mixing of the components, which is why manufacturing can be easily and safely (away from people) automated.

(9) It is also important that the components in the mixture are not explosive materials, necessitating only minor storage and transportation costs.

(10) Preferred embodiments of the invention result from combinations of the claims or individual features thereof.

(11) In the following, the invention will be described in detail with reference to several design examples. The design examples are intended to describe the invention without limiting it.

(12) In one design example of the invention, pure ammonium nitrate and ANFO (in each case with 13 g of the inventive composition in a cylindrical booster charge) with the following composition were brought to a detonative reaction: 6.5% Aerosil, 1% GMBs ca 100 m, 92.5% nitromethane.

(13) In the process, detonation velocities of ca. 4500 m/were measured, which indicates adequate suitability of the mixture for the initiation of non-detonator-sensitive commercial explosives to initiate larger amplifier charges and for direct use for special blasting (avalanches, ice, etc.).

(14) A non-limiting example of a detonator-sensitive booster charge as herein disclosed is illustrated in FIG. 1. FIG. 1 shows a detonator sensitive booster charge 1, an ignition device 2, a mixture comprising nitromethane and cavity forming means 3, and a concave curvature 4.