RU2301789C1 - 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 inventions is pertaining to the mixed blasting explosives used for formation of the charges in the explosion cavities in mining industry and building industry. The group of the inventions presents the method of manufacture of the blasting explosive and the blasting explosive produced by this method is tendered. The method of manufacture of the blasting explosive containing the granular ammonium nitrate (AN), the liquid fuel with addition of the surface active substance (SAS) and the explosive sensitizer provides for heating ammonium nitrate up to the temperature of 40-70°C, the aging of the ammonium nitrate at the temperature of the heating during 3-30 minutes, treatment of the heated ammonium nitrate with 0.5-7 mass % of the liquid fuel with the SAS additive, mixing with the sensitizer and refrigeration to the temperature below the phase transformation point of the ammonium nitrate IV-III. As the liquid fuel use the mineral and-or vegetable oil, and as the SAS additive use the fatty acids and-or the salts of the fatty acids, and-or esters of the fatty acids and the polyols. The purpose of the inventions is improvement of the explosive and operational characteristics of the loose mixed explosive composition containing the granular ammonium nitrate, the liquid fuel additive and the explosive sensitizer.

EFFECT: the invention ensures the improved explosive and operational characteristics of the loose mixed explosive composition containing the granular ammonium nitrate, the liquid fuel additive and the explosive sensitizer.

7 cl, 1 tbl, 1 ex

Description

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

The compositions of mixed explosives based on ammonium nitrate with the addition of liquid fuel and sensitizers are widely known and are actively used in blasting operations. The efficiency and stability of charges from such mixed explosives depends on the absorbency of ammonium nitrate granules, i.e. from the presence of cracks and pores. All varieties of granular ammonium nitrate are granules with a solid, shell-like surface, characterized by a higher density compared to the bulk of the substance inside the granules. Therefore, most of the existing methods for the manufacture of mixed explosives based on ammonium nitrate with the addition of liquid fuel are aimed at increasing the absorbency of ammonium nitrate granules by creating cracks and pores.

Known explosive mixture containing porous ammonium nitrate (90.7-26.6 wt.%), Mineral oil or a mixture of mineral oils (1.5-4.3 wt.%) And bulk explosive or a mixture of bulk explosives (the rest ) (Russian patent No. 2185354 C1, 07/20/2002, IPC C06B 31/28). This explosive mixture is made by mixing porous ammonium nitrate and free-flowing explosive until the bulk components are evenly distributed, followed by oiling the resulting mixture with mineral oil or a mixture of mineral oils at ambient temperature. It is allowed first to oil the ammonium nitrate with mineral oil, and then mix it with an explosive.

A known method of manufacturing a mixed explosive composition containing 95-97 wt.% Porous granular ammonium nitrate and 5-3 wt.% Liquid hydrocarbon fuel, including heating ammonium nitrate for its activation (transition from IV form to III form) to a temperature of 40-80 ° C and its subsequent cooling to a temperature below 32 ° C, holding at this temperature for the reverse transition of ammonium nitrate from form III to form IV, after exposure, the resulting nitrate is mixed with liquid hydrocarbon fuel (US patent 3103457 A, 09/10/1963, C06B 31/2 8).

Known mixed explosive composition containing liquid hydrocarbon fuel (diesel fuel), inorganic oxidizing agent (ammonium nitrate) and a sensitizer (aluminum, TNT, etc.) (US patent No. 3684597 A, 08/15/1972, IPC C06B 31/28). The method of this mixed explosive composition involves mixing a liquid hydrocarbon fuel and an inorganic oxidizing agent, grinding the resulting mixture, and mixing with an oil-containing surfactant. Surfactants can be mixed with liquid hydrocarbon fuels and inorganic oxidizing agents before grinding.

The closest analogue to the proposed invention is a method of manufacturing a mixed explosive when loading holes and wells and a mixed explosive containing granular ammonium nitrate, liquid fuel and solid dispersed additives. The method includes mixing dense granular ammonium nitrate with liquid combustible and solid dispersed additives and converting ammonium nitrate into a less dense porous state 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 (RF patent 2138009 C1, 09/20/1999, IPC F42D 1/08 )

A common drawback of all known explosive compositions obtained by known technologies is their lack of flowability due to the presence of an oil film on the surface of the granules of ammonium nitrate. When charging boreholes and boreholes in a pneumatic way, granules coalesce, which leads to a deterioration in the explosive characteristics of the mixed explosive composition.

The objective of the invention is to provide a method of manufacturing a mixed explosive containing granular ammonium nitrate, a liquid combustible additive and a sensitizer, which allows you to charge boreholes and wells pneumatically in underground workings.

The technical result of the invention is to improve the explosive and operational characteristics of a bulk mixed explosive composition containing granular ammonium nitrate, a liquid combustible additive and a sensitizer.

The technical result is achieved in a method of manufacturing an explosive substance containing granular ammonium nitrate (AC), liquid fuel with the addition of surface-active substances (surfactants) and an explosive sensitizer, including heating the AC to a temperature of 40-70 ° C, holding the AC at a heating temperature for 3-30 min, treatment of the heated AS with 0.5-0.7 wt.% Liquid fuel with the addition of surfactants, mixing with a sensitizer in an amount of 0.5-70 wt.% And cooling to a temperature below the phase transition point of AC IV-III. Mineral and / or vegetable oil is used as liquid fuel. As a surfactant additive, fatty acids and / or salts of fatty acids and / or esters of fatty acids and polyhydric alcohols are used, wherein surfactants are taken in an amount of 1-95 wt.% Of a liquid combustible additive.

As fatty acids can be used, for example, oleic acid or acids that are part of tall oil, with a unsaturated hydrocarbon chain. And also, for example, stearic acid can be used as fatty acids.

As salts of fatty acids can be used salts of alkali and / or alkaline earth metals, mainly calcium salts of fatty acids of synthetic or natural origin, for example, salts that are part of the solidol.

As an explosive sensitizer, any known explosive sensitizers can be used, both individual and mixed explosives in granular and / or scaled and / or powder form, and as an explosive sensitizer, granular and / or scaled TNT, crystalline hexogen, and / or ammonite and / or diammon.

In the proposed method for the manufacture of explosives before mixing with other components, the surface of the granules of ammonium nitrate is activated by heating the AC to a temperature of 40-70 ° C and then holding it at the same temperature for 3-30 minutes. When holding the AC at a heating temperature of less than 3 minutes, the process of crystalline modification does not end, and holding the AC at a heating temperature of more than 30 minutes requires an increase in the working volume of the equipment, which leads to a decrease in the economic benefits of the method and to an increase in explosion and fire hazard. As a result of heating above the phase transition point AC III-IV, which occurs in pure ammonium nitrate at a temperature of 32.3 ° С and a metastable transition, which occurs at a temperature of about 50 ° С, and exposure, during which drying is carried out, the solid solid surface of the granules is covered network of cracks. The appearance of cracks on the surface contributes to a more intensive penetration of the oil phase - liquid fuel into the body of the granules. Additives of surfactants, which are part of the liquid fuel, further enhance the effect of sorption and penetration of liquid fuel into the cracks formed on the surface of the granules. After mixing the activated AS with liquid fuel, including a surfactant, “dry” (not oily) granules are obtained, which are then mixed with an explosive sensitizer.

An example implementation of the method of manufacturing explosives.

The speakers are heated to a temperature of 70 ° C and maintained at a heating temperature for 25 minutes. Then the heated AS is treated with diesel fuel with the addition of tallow oil fatty acids as a surfactant. The granules obtained after processing are mixed with granulated TNT and cooled to a temperature of 30 ° C.

The final product is a well-flowing mass with a reduced tendency to caking during storage, as a result of which it is convenient and effective for charging holes and wells of various spatial directions (vertical, inclined, ascending) in underground workings by a pneumatic method with charges with a density of up to 1.3 g / cm ³ .

The absence of an oil film on the surface of the granules leads to a reduction in the pollution of the working space during pneumatic charging. According to the explosive characteristics, the composition obtained in this way surpasses similar mixtures, has a smaller critical diameter of detonation and a higher detonation speed, which allows for a more complete explosive transformation of the system in a detonation wave with increased energy release and less toxic gases during an explosion.

For the manufacture of explosives by the proposed method can be used speakers of all types and brands produced by industry, for example:

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

- AC waterproof grade ЖВГ according to GOST 14802 - a granular product for the manufacture of explosives such as ammonite and others,

- AC porous according to the specifications of manufacturers - a granular product with internal gas inclusions resulting from foaming.

The table shows the characteristics of samples manufactured by the proposed method, which indicate that the proposed method of manufacturing a mixed explosive improves the explosive and operational characteristics of a bulk mixed explosive composition containing granular ammonium nitrate, a liquid combustible additive and a sensitizer, compared with the corresponding characteristics of explosive compositions made by known methods.

Table indicator Samples one 2 3 four 5 6 7 8 9 1. The original ammonium nitrate and its properties: - brand Porous DVG GOST 2 GOST 2 GOST 2 GOST 2 GOST 2 GOST 2 GOST 2 - bulk density, g / cm ³ 0.8-0.82 0.88-0.90 094-0.96 0.94-0.96 094-0.96 094-0.96 094-0.96 094-0.96 094-0.96 2. composition of liquid fuel, wt.% (By weight of liquid fuel) fifty fifty fifty 90 80 90 5 95 (I-20) (I-20) (I-20) - (DT) (DT) (DT) (DT) (DT) - mineral oil
- vegetable oil
- surfactant fifty fifty fifty one hundred *** *** *** 95 5 (GIT) (GIT) (GIT) (GIT) (solidol) (SEM) (stearin) (GIT) (GIT) ** ** ** ** 10 twenty 10 ** ** (LCD) (LCD) (LCD) (LCD) (SaJ) (SEM) (LCD, LCD) (LCD) (LCD) 3. the composition of the explosive, wt.% - ammonium nitrate 87 87 87 87 87 87 87 70.5 70.5 - liquid combustible additive 3 3 3 3 3 3 3 4,5 4,5 - sensitizer (type) 10 10 10 10 10 10 10 25 25 4. properties of the explosive composition - bulk density, g / cm ³ 0.79-0.81 0.85-0.87 0.91-0.93 0.90-0.92 0.90-0.92 0.90-0.92 0.90-0.92 0.95-0.97 0.95-0.97 - the diameter of the charge d in the shell of a polymer pipe with a length of about 10 d, detonated completely, mm fifty 70 80 80 80 80 80 60 70 - charge detonation velocity in a polymer pipe with a diameter of 100 mm at bulk density, km / s 3.0-3.2 3.2-3.3 3.0-3.2 3.0-3.2 3.0-3.2 3.0-3.2 3.0-3.2 3.2-3.3 3.2-3.3

Designations used in the table:

the names of the substances that make up the liquid fuel are given in abbreviated form:

I-20 - industrial oil,

DT - diesel fuel,

GIT - fatty acids of tall oil,

Solid oil - grease solid oil brand Zh,

SEM - an emulsifier based on polyisobutylene and fatty acids,

Stearin - stearin (a mixture of fatty acids),

SAG - salts of fatty acids,

FA - fatty acids

** - Surfactant is a part of vegetable oil, the total content is given,

*** - vegetable oil is part of the surfactant, the total content is indicated,

**** - the oxygen balance of the samples is approximately equal to zero, and the heat of explosion is in the range of 3900-4000 kJ / kg.

Claims (7)

1. A method of manufacturing an explosive substance containing granular ammonium nitrate (AC), liquid fuel with a surfactant additive and an explosive sensitizer, including heating the AC to a temperature of 40-70 ° C, processing heated AC liquid fuel with a surfactant additive, mixing with a sensitizer and cooling to temperatures below the phase transition point AC IV-III, characterized in that the AS is maintained at a heating temperature for 3-30 minutes, the AS is treated with 0.5-7 wt.% liquid fuel with the addition of a surfactant, mineral and / or liquid are used as liquid fuel or grow oil, and fatty acids and / or salts of fatty acids and / or esters of fatty acids and polyhydric alcohols are used as surfactant additives, moreover, surfactants are taken in an amount of 1-95 wt.% of the liquid fuel, and the sensitizer is administered with mixing in an amount of 0.5-70 wt.%. 2. The method according to claim 1, characterized in that oleic acid or acids that are part of the tall oil with a unsaturated hydrocarbon chain are used as fatty acids. 3. The method according to claim 1, characterized in that as the salts of fatty acids use salts of alkali and / or alkaline earth metals, mainly calcium salts of fatty acids of synthetic or natural origin. 4. The method according to claim 1, characterized in that stearic acid is used as the fatty acid. 5. The method according to claim 1, characterized in that as the sensitizer use individual or mixed explosives in granular, scaly or powder form. 6. The method according to claim 1, characterized in that granular and / or scaled TNT, crystalline hexogen, and / or ammonite, and / or diammon are used as an explosive sensitizer. 7. An explosive substance containing ammonium nitrate, liquid fuel with the addition of surfactants and an explosive sensitizer, characterized in that it is manufactured by the method according to any one of claims 1 to 6.