RU2274630C2 - Composition for drilling and blasting operations - Google Patents

Abstract

FIELD: explosives.

SUBSTANCE: invention relates to explosives used in various-destination industrial drilling and blasting operations, in particular destined for breaking blocked stone and destroying various objects in safe mode. Explosive composition of invention contains sodium chlorate as solid oxidant, solid hydrocarbon in the form of pipes, cells, amendment tape, and film as fuel, and sodium sulfate functioning as catalyst. Solid hydrocarbon can be selected from polyethylene, polypropylene, and polystyrene.

EFFECT: diminished scattering over induction period and increased reliability and safety when carrying out blasting operations.

2 cl, 3 tbl

Description

The invention relates to explosive materials based on alkali metal chlorates, organic compounds and energy additives used in drilling and blasting for various purposes in industry, in particular for breaking block stone and destruction of various objects (boulders, foundations, oversized, etc.) sparing mode.

Currently, explosives are widely used in the national economy, the basis of which is ammonium nitrate [1]. Most of them have good performance properties. It is known the use of explosives based on potassium chlorates and perchlorates, as well as ammonium perchlorate in the First World War in France, England and Germany for the equipment of mortar and mortar shells [2, 3]. However, when using the above compositions for breaking block stone, the yield of finished products is no more than 20% [2] due to the detonation effect of the explosion products on the rock. To reduce the harmful effects of an explosion, various methods and means are used, for example, loosening charges with reduced specific explosive consumption; structures of soft loading charges with air, water gaps and gaps filled with these and other inert media [3]. Recently, in the extraction of block stone, they are trying to use substances that create pressure in the hole due to the combustion reaction in the deflagration rather than detonation mode, or in the low-speed detonation mode. The use of compositions (compositions) with a reduced detonation velocity, for example, Granilenov-1, -2, -3, Forsitov, solves this problem only partially: the price rises, environmental problems arise, etc.

The return to the use of black powder in some quarries is a necessary measure, because the danger of handling it is well known. Despite this, the use of black powder, as well as the Granilenov, Forsyths in the extraction of block stone, is explained by their good dynamic parameters of the process of physico-chemical transformation - a short response time (from microseconds to several milliseconds).

Of particular interest are compounds based on sodium chlorate (CN) and liquid and solid hydrocarbons (HC) (for example, diesel fuel, mineral oil, polyethylene, polypropylene) due to their low cost, the ability to mechanize transport and charging operations; there are no contraindications for the direct preparation of two-component compositions in a mine (quarry), which increases the level of work safety. According to preliminary thermodynamic calculations, the efficiency of combustion products (RT) - the main component in the operation of the explosion - composition based on a stoichiometric mixture of CN and HC has RT≈720 kJ / kg. Larger RT values can be obtained using a composition based on perchlorates, primarily ammonium perchlorate. The wider use of such compositions was limited, mainly due to the high cost, especially based on ammonium perchlorate [1]. Currently, they have found application only in Japan (Karlites) and partially in France (Sevronites). Chlorate-based formulations are cheaper and safer to handle.

Another advantage of compositions based on perchlorates and chlorates is their higher density compared to mixtures based on ammonium nitrate (density of nitrate is 1730 kg / m ³ , density of sodium chlorate is 2490 kg / m ³ [4]).

The closest analogue of the claimed invention is a composition for drilling and blasting operations according to the patent of Russia No. 2152376 C1, 07/10/2000, IPC 7 C 06 B 29/08 [5]. The composition according to this patent consists of a solid oxidizing agent - sodium chlorate and combustible - liquid and solid hydrocarbons with the ratio: liquid hydrocarbons 7 ÷ 11.6 wt.%, Solid hydrocarbons 17.3 ÷ 20.9 wt.% And the rest of sodium chlorate. The composition as liquid hydrocarbons contains diesel fuel, kerosene or fuel oil, as solid hydrocarbons - polyethylene, polypropylene or polystyrene. The main disadvantage of the compositions using liquid hydrocarbons and solid hydrocarbons in the form of a powder is the possibility, when the critical diameter of the charge exceeds the value of the transition of the combustion from the deflagration to detonation mode with strong brisance (crushing effect). Other disadvantages of the prototype is the increased hygroscopicity during storage and the associated variable induction period. This is fraught with the simultaneous actuation of charges and, as a consequence, failure.

The technical task of the invention is to create a composition with less dependence on storage conditions, less variation in the induction period — greater reliability during blasting, lowering the cost of the composition and improving the safety of work, while retaining the advantages of the prototype.

To solve this problem, a blasting composition is proposed that contains a solid oxidizing agent - sodium chlorate, a solid hydrocarbon in the form of tubes, honeycombs, Correx tape, films and additionally contains sodium chloride as a catalyst with a ratio of components, wt.%:

solid hydrocarbon in the form of tubes, honeycombs, Correx tape, films  - 4.3 ÷ 19.8 sodium chloride - 5 ÷ 15; sodium chlorate rest

Replacing sodium chlorate with potassium or calcium chlorates and, accordingly, sodium chloride with potassium or calcium chlorides should lead to similar results. Since sodium chlorate is a more common and cheap product, further data is provided only for the composition based on sodium chlorate. The choice of a specific composition (the proportion of sodium chloride in the composition) was carried out taking into account the data obtained in the study of combustion rates both under atmospheric conditions and in a manometric bomb (imitation of natural conditions), taking into account the thermodynamics of the process. Depending on the hydrocarbon class, the efficiency of the mixture can vary by no more than 15%, with paraffins (general formula C _n H _{2n + 2} ) higher and aromatic hydrocarbons (general formula C _n H _n ) lower than olefins (total formula C _n H _2n ). A change in charge efficiency due to a change in the hydrocarbon class also manifests itself at the burning rate. Table 1 below shows the data from comparative tests in a laboratory setup under atmospheric conditions, and in table 2 in a manometric bomb. To obtain more reliable data, all tests were at least duplicated.

Table 1
The effect of NaCl in the composition of sodium chlorate with polyethylene on the linear burning rate NaCl, wt.% about 4.8 9.1 13.1 twenty thirty U, mm / c 1.01 1.01 0.96 1.02 0.85 0.83 Z 1.0 1.0 0.95 1.02 1.05 0.92

The first row of the table presents data on the content of sodium chloride in the composition. The second line contains experimental data on the effect of sodium chloride on the linear burning rate. The last row of the table shows the Z data - the ratio of the experimentally measured burning rate to the calculated one, determined by the value of the excess coefficient of the oxidizing agent (from the approximating equation after processing the array of experimental data). From [4] it follows that the introduction of sodium chloride in sodium chlorate not only reduces hygroscopicity, but also the cost of the composition, thereby improving its operational characteristics: However, an increase in the content of sodium chloride over 15% is unprofitable both due to a decrease in the linear burning rate and due to a noticeable drop in the energy of the process (see table 2).

table 2
The effect of sodium chloride in the composition on the dynamic and energy parameters of the process NaCl, wt.% 0 4.8 9.1 13.1 τ _ind , sec 0.32 0.23 0.20 0.11 RT. kJ / kg 472 447 430 403 RT _i / RT ₀ 1.00 0.95 0.91 0.85

The table shows that an increase in the content of sodium chloride in the composition leads to a reduction in the induction period (second row), i.e. to improve the dynamic characteristics of the composition. At the same time, an increase in the content of more than 15% leads to a noticeable (15 and more%) decrease in energy, which should lead to an overspending of the composition (3 and 4 rows of the table) when operating on a quarry. As for the results of table 1, the experiments were at least duplicated. Energy data should be considered as high-quality due to the lack of proper thermal insulation and certification of the manometric bomb. Since the tests were carried out under identical conditions, the conclusions on the qualitative impact on the energy of the process should be considered justified.

Table 3.
The effect of the hydrocarbon class on the linear burning rate of the mixture with sodium chlorate (sodium chloride content 13.1 wt.%) HC class Polyolefins Aromatic core polyolefins Paraffins Concentration, wt.% 4.3 9.1 19.8 4.4 8.7 19.8 4.3 8.9 19.8 U, mm / s 0.64 1,02 0.99 0.51 0.97 0.72 0.64 1,04 0.95

The possibility of technical implementation of the invention is not in doubt, since

1 - all components of the composition are produced by domestic industry without restrictions,

2 - the technology for producing mixtures is almost similar to the technology for producing mixtures with ammonium perchlorate, but is safer.

Field trials were conducted on the proposed compositions and the technology for their manufacture was tested.

Information sources

1. Dubnov L.V., Bakharevich N.S., Romanov A.I. Industrial explosives. - M .: Nedra, 1973. - 320 p.

2. Ligotsky D.N. // Losses of granite during mining and processing: Problems of the theory of quarry design: Interuniversity. Sat scientific tr St. Petersburg, 1995.S. 76-77.

3. Kotov L.R., Kutsenko Y.S., Kulakevich Y.S. et al. Hose charges for breaking granite blocks // Physical problems of rock mass destruction. Proceedings of the International Scientific Conference, Moscow, 1999, September 7-11, pp. 217-218.

4. Schreiber S.S. The production of bertholate salt and other chlorates. - M: GONTINKTP, 1938 .-- 367 p.

5. Patent of Russia No. 2152376 dated 12/10/1998.

Claims (2)

1. Composition for drilling and blasting operations, containing a solid oxidizing agent - sodium chlorate, fuel - a solid hydrocarbon, characterized in that it additionally contains sodium chloride as a catalyst, and it contains solid hydrocarbon in the form of tubes, honeycombs, Correx tape, films at the following ratio of components, wt.%: Solid hydrocarbon in the form of tubes, honeycombs, Correx tape, films 4.3-19.8 Sodium chloride 5.0-15 Sodium chlorate Rest 2. The composition according to claim 1, characterized in that as solid hydrocarbons it contains polyethylene, polypropylene, polystyrene.