RU2301788C1 - Method of manufacture of the blasting explosive and the blasting explosive produced by this method - Google Patents

Abstract

FIELD: chemical industry; mining industry; building industry; methods of production of the mixed blasting explosives.

SUBSTANCE: the group of the inventions is pertaining to manufacture of the mixed blasting explosives used for the molding of the charges arranged in the explosion cavities in mining and building. The group of the inventions presents the method of manufacture of the blasting explosive and the blasting explosive manufactured by this method. The method of manufacture of the blasting explosive includes the heating of the granulated ammonium nitrate up to the temperature by 5-10°C higher than the melting temperature of dinitrotoluene (DNT), introduction at stirring action in the ammonium nitrate of the solid DNT in the crystalline form with the dimension of the agglomerate of no more than 5 mm in amount of 10-20 mass %, stirring action till completion of the DNT adsorption process in the ammonium nitrate, cooling of the produced mixture to the temperature of no more than 50°C. The invention has the purpose to improve the explosive and operational characteristics of the loose nixed blasting explosive on the basis of the ammonium nitrate and dinitrotoluene.

EFFECT: the invention ensures production of the loose mixed blasting explosives on the basis of the ammonium nitrate and dinitrotoluene with the improved explosive and operational characteristics.

2 cl, 1 tbl, 1 ex

Description

The invention relates to mixed explosives used to form charges in explosive cavities in mining and construction.

Compositions of mixed explosives based on ammonium nitrate and dinitrotoluene have long been widely known and are actively used in blasting operations (GB 190404699 A, 10.20.1904, IPC C06B 1/04; GB 773664, 05/05/1957, IPC C06B 31/42; GB 14545 , September 14, 1905, IPC C06B 31/42; RU 2216529 C2, 11/20/2003, IPC C06B 31/32, C06B 25/04; RU 2222518 C2, 01/27/2004, IPC C06B 31/28; SU 438174, 07/30/1974 IPC C06B 1/06).

A known method of manufacturing a mixed explosive composition when loading holes and wells (according to the patent of Russian Federation 2138009 C1, 09/20/1999, IPC F42D 1/08), comprising mixing dense granular ammonium nitrate with liquid combustible and solid dispersed additives and converting ammonium nitrate into a less dense porous condition by heating it to a temperature above 32.3 ° C. A liquid combustible additive is introduced into the heated nitrate, and the finished mixture is cooled to a temperature below 32.3 ° C or to ambient temperature, after which the mixture is fed into the well or hole.

A known method of preparing an explosive composition (US patent No. 5728969, 03.17.1998, IPC C06B 21/00), according to which 86 wt.% Ammonium nitrate is heated to a temperature of 70 ° C and mixed with 14 wt.% Liquid dinitrotoluene mixture obtained by mixing 2,6-dinitrotoluene with dinitrotoluene and heating the mixture to 70 ° C, then the resulting mixture of heated ammonium nitrate and heated dinitrotoluene mixture is cooled.

As the closest analogue of the proposed method for the manufacture of explosives and explosives can be adopted a method of manufacturing an explosive composition and explosives according to Japan patent 10158085 A, 06/16/1998. According to the method described in the aforementioned patent, dinitrotoluene in a molten or solid form is added to ammonia nitrate of a certain dispersion with stirring at a temperature of 35-160 ° C, preferably at a temperature of 50-70 ° C, stirred and cooled. As a result, dinitrotoluene penetrates into the pores and cracks of ammonium nitrate and covers its surface. The explosive obtained in this way has the following ratio of components, wt.%:

dinitrotoluene 1-50 (mainly 70-96) ammonium nitrate 30-99 (mainly 4-30)

All the above methods of manufacturing explosives, including the method adopted as the closest analogue, have several disadvantages that affect the properties of the resulting explosives. The nitrate granules are unevenly saturated and “oiled”, prone to clumping, which leads to a deterioration in the flowability of the explosive and, as a result, to a decrease in its effectiveness.

The technical task of the invention is to provide a method of manufacturing a mixed explosive based on ammonium nitrate and dinitrotoluene, which allows to obtain an explosive for loading holes and wells pneumatically during underground workings.

The technical result of the invention is to improve the explosive and operational characteristics of a bulk mixed explosive based on ammonium nitrate (AS) and dinitrotoluene (DNT).

The specified technical result is achieved by the fact that in the method of manufacturing an explosive substance, comprising introducing solid dinitrotoluene into granular ammonium nitrate, stirring and cooling, before introducing dinitrotoluene into ammonium nitrate, it is heated to a temperature of 5-10 ° C. above the melting point of dinitrotoluene, solid dinitrotoluene with stirring in crystalline form with an agglomerate size of not more than 5 mm in an amount of 10-20 wt.%, stirring is carried out until dinitrotoluene adsorption is completed on ammonium nitrate, and cooling is carried out to a temperature not exceeding 50 ° C.

For the manufacture of explosives in this way can be used solid ammonium nitrate in granular form of any grades (general technical, agricultural, porous, etc.).

Since technical DNT is a mixture of isomers in various proportions, the melting temperature of the technical product is not strictly constant and can vary, in particular, within 50-65 ° C (Zbarsky V.Ya., Zhilin V.F. Toluol and his nitro derivatives. M: Editorial URSS, 2000, 270 pp.). To ensure the penetration of DNT into the pores and cracks of the AC and to create a uniform coating of the DNT on the AC, it is necessary to preheat the AC to a temperature above the melting temperature of the DNT. Heating the speaker can be carried out by any of the known methods.

The results of the experiments showed that the quality of the coating of DNT on the AS (in particular, uniformity) and the degree of penetration of DNT into the pores and cracks of the AS is determined by the simultaneous observance of three conditions, namely

- temperature pre-heating speakers

- the dispersion of DNT introduced into the AS,

- the amount (10-20 wt.%) injected DNT.

It was also experimentally established that the heating temperature of the AS should exceed the melting temperature of DNT by 5-10 ° C, in this case, the heat reserve in the heated AS is sufficient to melt the DNT and for the most efficient penetration of the DNT into the granules of the AS.

The size of the DNT agglomerates should be no more than 5 mm, since with a larger size of the agglomerates, there will be uneven melting of the DNT, which will require an increase in the heating temperature of the ACs over 5-10 ° C of the melting temperature of the DNTs, and this in turn will lead to an uneven coating of the AC granules.

The content of DNT in the amount of 10-20 wt.% Is close to stoichiometric, in which an explosive of this composition has the greatest efficiency, and at the same time, this amount of DNT is sufficient to ensure uniform coating of the granules. When the content of DNT in the amount of less than 10 wt.% Was observed insufficient coverage of the granules of AS, and when using DNT in an amount of more than 20 wt.% Was observed uneven coating of granules of AS.

An example embodiment of the invention:

AU granulated in accordance with GOST 2-85 in the amount of 4.25 kg (i.e., 83.3 wt.%) Is heated to a temperature of 70 ° C in an oven heated to 90 ° C. Next, the heated speaker is poured into a heated mixing tank. 0.85 kg (16.7 wt.%) Of crystalline DNT with an agglomerate size of not more than 5 mm is introduced into the heated AS stream with constant stirring. DNT melts and penetrates into the granules (particles) of AS in liquid form. The resulting system is mixed until the complete disappearance of the particles of DNT, i.e. until the complete melting of DNT and its complete adsorption on AC granules. The resulting mixture is cooled to a temperature of + 30 °.

The table shows the characteristics of samples of explosives manufactured by the proposed method.

For the manufacture of samples used speakers of various types and brands manufactured by the Russian industry:

- AU according to GOST 2 85 - a granular product for agriculture and technical purposes;

- AU waterproof grade ZhVG according to GOST 14802 - a granular product for the manufacture of explosives such as ammonite and others.

- AC “porous” brand according to the specifications of manufacturers — a granular product with internal gas inclusions obtained by foaming for the manufacture of mixed explosives with liquid combustible additives.

Since to obtain explosives according to the proposed method can be used various brands (varieties) of AS, which in the initial state differ from each other in a number of indicators, then, accordingly, the resulting product will also have slightly different properties (see table).

The main properties of the obtained product by the proposed method:

- the product has a state similar to the state of the initial AS, but the granules of the AS are saturated with dinitrotoluene, and the presence of the latter in the mixture externally (visually) appears only in a color change (if the initial AS was white) and the appearance of a smell characteristic of DNT;

- the product has good flowability and does not dust, since all the dust particles are cemented with dinitrotoluene;

- the product is well charged into the holes (wells) pneumatically with the formation of a stable charge with a density of up to 1.3 g / cm ³ (which to some extent depends on the initial AC, see table);

- when the product is wetted, which is used during pneumatic charging or when the charge is in a humid environment, DNT is not separated from the mixture (as is observed for mixtures of AS with liquid petroleum products);

- explosive characteristics and explosive efficiency are higher, in comparison with the prototype and with mechanical mixtures AC + oil + DNT or mixtures AC + oil (mixtures of type ASDT);

- the product has high physical stability and there is no change in properties during storage.

Table Indicator Samples one 2 3 four 5 1. source speaker: GOST Zhvg Porous TU GOST 2 GOST 2 - brand - bulk density, g / cm ³ 0.92-0.95 0.88-0.90 0.75-0.80 0.92-0.95 0.92-0.45 2. composition of explosives, wt.%: - ammonium nitrate 85 85 85 90 80 - dinitrotoluene (size of agglomerates no more than 5 mm) fifteen fifteen fifteen 10 twenty 3. AC heating temperature 65 70 68 70 65 4. BC properties dry loose granules, in size corresponding to the granulometric composition of the original AS with an increased to 5-8% content of fine (less than 1 mm) fraction, with the appearance of yellow staining for white AS granules - appearance - bulk density 0.92-0.95 0.90-0.92 0.77-0.82 0.90-0.93 0.95-0.95 - oxygen balance,% -0.16 -0.16 -0.16 +6.56 -6.88 - the diameter of the charge d in the shell of a polymer pipe with a length of about 10d, detonated completely, mm one hundred 80 80 one hundred 125 - charge detonation velocity in a polymer pipe with a diameter of 100 mm at a bulk density of km / s 2.5-2.6 2.5-2.8 2.9-3.3 2.3-2.5 <1.5 attenuation

Claims (2)

1. A method of manufacturing an explosive substance, comprising introducing solid dinitrotoluene into granular ammonium nitrate, mixing and cooling, characterized in that before adding dinitrotoluene to ammonium nitrate it is heated to a temperature of 5-10 ° C. above the melting temperature of dinitrotoluene, solid dinitrotoluene is introduced with stirring in crystalline form with an agglomerate size of not more than 5 mm in an amount of 10-20 wt.%, mixing is carried out until dinitrotoluene adsorption on ammonium nitrate is completed, and cooling is performed on exist up to a temperature of no higher than 50 ° C. 2. An explosive substance containing ammonium nitrate and dinitrotoluene, characterized in that it is obtained by the method according to claim 1.