RU2033989C1 - Method of preparing of explosives containing ammonium nitrate, hydrocarbon fuel and surface-active substance - Google Patents

Abstract

FIELD: explosive compositions. SUBSTANCE: ammonium nitrate is stirred with emulsion obtained by water addition to hydrocarbon fuel and surface-active substance. Concentration of water and surface-active substance is 0.2-0.5 and 0.1-0.5 wt.-%, respectively, of explosive. Pentaerythritol or glycerol esters with fatty acids C₁₂-C₂₀ or pentaerythritol polyesters with synthetic acids C₂₁-C₂₅ were used as surface-active substances. EFFECT: improved method of explosives preparing. 3 cl

Description

 The invention relates to methods for producing explosive compositions (mixtures) based on an oxidizing agent, for example ammonium nitrate and hydrocarbon fuel, for blasting in mining.

Known methods for producing such explosives, referred to as ANFO abroad and “granulites” in our country, boil down to mixing nitrate granules with liquid or solid hydrocarbons (their mutual connections are possible) and, if necessary, with aluminum. Mixing is carried out cold or with heated components [1]
The domestic assortment of explosives obtained by varieties of this method includes granulites of the grades S-6M, AC-4, AC-8, AC-8B, etc. All of them provide technical tasks for the destruction of rocks using only borehole charges with a diameter of at least 100 mm. They are characterized by negative qualities, such as dusting and removal of granules during pneumatic charging, spillage of explosives from the well, etc. However, the most significant drawback of these explosives is the unsatisfactory ability to detonate in hole charges with a diameter of 40-50 mm, the detonation process, as a rule, decays at a charge length of about 2 mm.

 Stable granulites are also known, which contain, along with hydrocarbon fuels, additives of high-melting or solid surfactants. One of such granular granules ASD, the manufacturing method of which is adopted as a prototype [2] includes the following components, ammonium nitrate 92-96, diesel fuel 5.6, stabilizing additive (bituminous or high molecular weight acid builder or petroleum softener or corrosion inhibitor) 0.4- TU7511903-541-90.

The method for producing ASD includes the following stages:
preparation of ammonium nitrate (transport, unloading, crushing of packed pieces, sifting, dosing);
preparation of diesel fuel and structure-forming additives (transport, dosing);
preparation of the mixture (solution) of the additive in diesel fuel;
mixing a mixture of hydrocarbons with ammonium nitrate.

 The ASD granulite obtained by this method is intended for blasting when charging dry and drained wells on a day surface, i.e. not suitable for use in borehole charges.

 The technical result of the invention is the development of a method for producing granular explosives based on ammonium nitrate and hydrocarbon fuel with higher detonation properties, allowing their use in blast holes.

This is achieved by the fact that the hydrocarbons to the granules of ammonium nitrate are introduced into the mixture in the form of a water-oil (oil-water) emulsion obtained in the presence of emulsifiers (stabilizers) of fatty acid esters with a carbon chain length of C ₁₂ -C ₂₀ with polyalcohols pentaerythritol or glycerol or polyesters of pentaerythritol with synthetic acids with a carbon chain length of C ₂₁ -C ₂₅ , in the following ratio, wt. water 0.2-0.5, emulsifier 0.1-0.5 from explosives.

 The resulting emulsion is mixed with nitrate in a ratio of about 5-95% and either a commercial explosive is obtained, or aluminum is added and aluminized granulite is obtained.

PRI me R. In a stirred vessel prepared emulsifier solution in a hydrocarbon fuel (temperature 20-70 ° ^C) and this solution is fed into the emulsification unit in which water is supplied at the same time. The resulting emulsion with microdroplets of not more than 50 μm enters the loading hatch of the mixer, where it is mixed with granules of ammonium nitrate. If necessary, dispersed aluminum can be added to the composition, which is introduced in a separate mixing apparatus of a similar design. Commodity explosives, after exiting the mixer, are packed in bags, loaded into temporary storage bins or into the hopper of a charging machine.

Claims (3)

 1. METHOD FOR PRODUCING EXPLOSIVE COMPOSITIONS CONTAINING AMMONIA NITRATE, HYDROCARBON FUEL AND SURFACE-ACTIVE SUBSTANCE, including the introduction of a surface-active substance into a hydrocarbon fuel and mixing the resulting mixture with water, mixed with to hydrocarbon fuels and surfactants.  2. The method according to claim 1, characterized in that the water is used in an amount of 0.2 to 0.5 wt. and a surfactant in an amount of 0.1 to 0.5 wt. explosive composition. 3. The method according to claim 1 or 2, characterized in that as the surfactant use polyesters of pentaerythritol or glycerol with fatty acids with a carbon chain length of C _{1 2} - C _{2 0} or polyesters of pentaerythritol with synthetic acids with a carbon chain length C _{2 1} C _{2 5} .