RU2522534C1 - Stick-detonator for industrial blasting - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: stick-detonator for industrial blasting comprises one or two through channels and a nest for the capsule, it is manufactured using cast moulding of mixed explosive containing 50-70 wt % trinitrotoluene and 50-30 wt % pentaerithrityl tetranitrate, which did not pass the recrystallisation stage, in a cylindrical shell of a polymeric material or multi-layer paper with thickness of 0.5-3.0 mm.

EFFECT: process of making stick-detonator is simplified.

1 dwg

Description

The invention relates to the field of industrial blasting equipment and industrial explosives, specifically to the field of detonator drafts of mixed explosives, used mainly for industrial blasting during drilling and blasting operations at mining enterprises. A cast industrial checker-detonator (BH) of injection molding explosive (BB) containing trotyl and pentaerythritol tetranitrate (TEN), having one or two through channels and a socket for the detonator capsule, is claimed.

To date, there are a number of cast mixed checkers-detonators used or recommended for use in the mining industry. This, for example, checkers TG-500 (OST 84-411-80), TGF-850E (utility model RU No. 3642 of 03/21/96), PDP-300, -400, -600 (utility model RU No. 13091 of 26.10. 99) and other SD on utility models RU No. 8112, 12238, 22535, 36506, 41514, and also according to the invention, patent RU No. 2177927, C06C 7/00, F42B 1/04, publ. 01/10/2002

So, in RU No. 2177927, an SD is described, including a cylindrical body, in which an explosive charge is placed with a through channel and a socket, the inlet openings of which are connected by a recess, while the SD is made of a mixture containing 50-70 wt.% TNT and 50-30 wt.% highly dispersed recrystallized heating element embedded in a casing made of a polymer material, and the distances measured by the diameter of the checker from its cylindrical surface to the cylindrical surfaces of the through channel and socket are equal, and the casing is a shell 0.5-3 m thick with rounded edges at the ends and annular projections on a cylindrical surface. This decision was made as a prototype.

All of these solutions, including the prototype, are structurally of the same type (they have a cylindrical shape, a through channel and a slot for a detonator capsule of a non-electric initiation system - NSI) and are distinguished by a BB compound or a casing, which is used as a paper, plastic case or shrink film . They are made from explosives, which are fusible mixtures of TNT with RDX or TEN. Similar pentolite (from a mixture of TNT with TEN) detonator blocks are produced abroad, for example, by Maxam (Spain) and Troyan Corporation (USA).

A feature of these BHs is the use of recrystallized TENA, which belongs to the category of expensive material. The use of TENA provides reliable initiation.

Currently, in the manufacture of a mixture of TNT-TEN, a dispersed free-flowing and recrystallized TEN is used. Recrystallization in the manufacturing process of the heating element is carried out in order to remove excess acid (surface and intracrystalline) and obtain a granular product. TEN is one of the powerful blasting explosives, for the production of which there is an almost unlimited raw material base, since the primary materials for its production are synthetic products.

A feature of the TENA production process is that the initial product pentaerythritol is a solid with a high melting point. The dosage of the solid starting component is much more difficult than the dosage of liquids. Industrial production of heating elements can be carried out in two ways: two-stage - with the preliminary production of pentaerythritol sulfate and its subsequent conversion to nitrate, and one-stage - direct production of pentaerythritol nitrate. In both cases, the process is carried out by adding pentaerythritol to the corresponding apparatus filled with sulfuric or nitric acid. In this case, the latter is dissolved in these acids. The dissolution process precedes the esterification reaction and, apparently, sets the overall speed. Good mixing and the presence of sufficiently small (not clumped into lumps) pentaerythritol is a necessary condition for the technological design of the esterification process. This technology is used to obtain a heating element that meets the requirements for crystallized heating elements, in accordance with which a heating element must have:

1) appearance - white crystalline powder (a slightly gray shade is allowed) without impurities visible to the eye, and without obvious signs of soaking;

2) melting point in the range of 138-140 ° C;

3) the moisture and volatile substances content is not more than 0.1%;

4) the content of impurities insoluble in acetone at ordinary temperature is not more than 0.1%;

5) ash content of not more than 0.2%, including silica, not more than 0.01%;

6) lack of free acids;

7) resistance, determined by the concentration of hydrogen ions at 110 ° C for 8 hours, not lower than 5.5;

8) resistance to iodine starch test 1 hour at 80 ° C.

The development of organic synthesis made it possible to reduce the cost of production of starting materials for the preparation of pentaerythritol - formaldehyde and acetaldehyde, which was the incentive for the emergence of a wide production of heating elements. Formaldehyde is currently being prepared in large quantities from synthetic methanol. Acetaldehyde is obtained from acetylene by catalytic hydration in the presence of mercury salts. Nevertheless, at present the cost of TEN is still high, and therefore in the peaceful industry it is mainly used in detonator capsules and is used to prepare a detonating cord.

The competition of manufacturers puts the task of reducing the cost of SD on the agenda. This is also confirmed by the results of marketing research, which indicates that consumer enterprises usually give a clear preference to cheaper drafts, despite the fact that their share in the total cost of used industrial explosives is small.

Since the technological processes for the production of bastards are close to each other, the main tool to reduce the cost of bastards can be the cheapening of the material of the checker (BB). The cost of mixed checkers is determined, first of all, by the price of an explosive filler (RDX and PETN), which is very expensive.

The present invention is aimed at achieving a technical result, which consists in simplifying the design by replacing the expensive highly dispersed recrystallized heating element with an unrecrystallized heating element while maintaining all the explosive properties presented as standard indicators for SD. This will significantly reduce the cost of new detonator drafts and thereby increase their competitiveness.

According to the proposed technical solution, the specified technical result is achieved by the fact that the blast furnace is made of an injection mixture of TNT and non-recrystallized heating element. In particular, in this non-recrystallized heater, the surface acid can be neutralized during technological washing after the nitration process is completed and the finished acid product is discharged from the nitration apparatus.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the desired technical result.

The figure 1 shows a checker detonator standard design.

The detonator bomb for industrial blasting (Fig. 1) contains one or two through channels 1 and a socket 2 for the capsule, is made by pouring from a mixed explosive containing 50-70 wt.% TNT and 50-30 wt.% Pentaerythritol tetranitrate (TEN) , which has not passed the recrystallization stage, into a cylindrical shell made of a polymeric material or multilayer paper with a thickness of 0.5-3.0 mm.

Currently, in the manufacture of a mixture of TNT-TEN, a dispersed free-flowing and recrystallized TEN is used. Recrystallization in the manufacturing process of the heating element is carried out in order to remove excess acid (surface and intracrystalline) and to obtain precisely a granular product.

On the other hand, in the technological processes for the manufacture of injection moldings with a periodic method of production, the flowability of the components used is not a critical indicator. Also, the presence of inter- and intracrystalline acid for TENA, which is not intended for long-term (more than 10 days) storage as an individual product, does not seem critical.

Therefore, for such a checker, the simplest way would be to use non-recrystallized TEN. In this case, the phase of recrystallization of acidic heating element in acetone, which is significant in terms of material costs, is eliminated, which is replaced by neutralization (washing) with an aqueous soda solution of an acidic product from surface acid.

Studies performed by the authors showed that the use of this product in the composition of the TNT-TEN injection formulation does not lead to a deterioration in the physical and chemical stability of the drafts, does not change its explosive characteristics (table 1 - comparative assessment of some physicochemical and explosive indicators of drafts), to the initiating impulse (table 2 - assessment of the susceptibility of the detonator checker to the initiating impulse from standard means of initiation) and the fluidity of the composition for free pouring technology.

Table 1 Name of indicator Value for checkers (average of three measurements) full-time experienced with acidic heating elements 1. Appearance Cast yellow 2. The density of the checkers, g / cm ³ , 1,58 1,58 3. Mass fraction of components,% TNT 50 ± 5 50 ± 5 TEN 50 ± 5 50 ± 5 4. The speed of detonation (at a density of 1.58 g / cm ³ ), m / s, 7490 7500 5. Heat of explosion, kcal / kg 1019 1004 6. Sensitivity to shock in accordance with GOST 4545: lower limit in the device 2, mm 70 70 the frequency of explosions in the device 1,% 45 44 7. The sensitivity to friction on the device K-44-3, the lower limit, kgf / cm ² 4000 4000

table 2 Detonator checker Number of checkers for each option The number of tests from the means of initiation for each option Test results Non-electric initiation system Rionel Detonating cord DShE-6 Established fifteen 9 6 Total detonation The claimed

The conducted studies provided a sufficient basis for work on the creation of an industrial design of a cast checker-detonator from an explosive mixture of TNT-TEN unrecrystallized, stabilized by neutralizing the acid on its surface. TEN is a neutral substance and does not act on metals, but with prolonged interaction with alkalis and acids it decomposes. In this regard, it seems appropriate, as an option, to neutralize the surface acid in the non-recrystallized heating element (in the surface layer of the heating element), for example, during technological washing after the nitration process is completed and the finished acid product is discharged from the nitration apparatus.

The use of the claimed invention will reduce the cost of detonator drafts, increase the profitability of their production and reduce the cost of drilling and blasting operations at mining enterprises.

Claims (1)

Detonator bomb for industrial blasting, consisting of a shell and a cast charge of a mixed explosive containing trotyl and pentaerythritol tetranitrate and having one or two channels and one socket, connected by a recess with one of the channels, characterized in that pentaerythritol tetranitrate is used as pentaerythritol tetranitrate non-recrystallized or pentaerythritol tetranitrate non-recrystallized with acid neutralized in the surface layer.