KR20030087123A - Low density ammonium nitrate fuel oil with the improved power and small odor - Google Patents

Abstract

PURPOSE: Provided is a low specific gravity ammonium nitrate fuel oil(ANFO) for open-air and tunnel blasting which has improved explosion speed and power, stability and less smell by using prill ammonium nitrate having lower specific gravity density and higher gasoline absorption than conventional prill ammonium nitrate as an oxidizer. CONSTITUTION: The ammonium nitrate fuel oil(ANFO) comprises the components of: prill ammonium nitrate as an oxidizer, having apparent specific density of 0.6-0.75g/cc and particle size less than 3.36mm(including 20% of particles less than 1.41mm); gasoline as a combustible material, having initial boiling point higher than 150deg.C; and 0.05-0.20wt.% of anti-caking agent for preventing the solidification of explosives.

Description

LOW DENSITY AMMONIUM NITRATE FUEL OIL WITH THE IMPROVED POWER AND SMALL ODOR}

The present invention relates to ultra-explosives used in open-air and tunnel blasting sites, low-density super-explosives (Ammonium Nitrate Fuel Oil, simply referred to as ANFO) to impart more pores inside the ammonium prill ammonium nitrate to maximize the speed It is about.

If the pore inside the ammonium prill increases, the speed of explosion increases. The reason for this is as follows. First of all, the porosity means that the mixture is absorbed well when mixed with light oil such as activated carbon which has excellent adsorption property, and penetrates deeply into the inside of the prill, thereby increasing the degree of miscibility. This degree of miscibility is related to the reaction rate. If the degree of miscibility is good, the contact surface area of the fuel and the oxidant is widened, so that the explosion rate is increased. Secondly, in order for the explosive to be expelled by the detonator, air bubbles are required as hot spots to continuously maintain high explosive power, and the pores contained in the ammonium prills perform this role. In other words, the more pores, the more the explosion speed increases and maintains it continuously. The principle of the hot spot is that when the explosive explodes, this explosion pressure compresses the surrounding air bubbles. As a result of this adiabatic compression, a high temperature is generated and a sensitizer acts to sustain the explosive stably. To do.

The method of producing ammonium pryl nitrate having a low specific gravity with a lot of bubbles is made by two methods. A brief description of how to make ammonium fritrate follows.

When hot ammonium nitrate solution containing about 3 to 5% of water is sprinkled in a tower about 40 to 60 m high and blows hot air from the bottom, the ammonium nitrate solution is formed into prill-like particles and the water present inside while descending 45 m It is dried by the hot air blown from the bottom, and it is left as a pore as it leaves the moisture.

Ammonium nitrate with a specific gravity of 0.75 to 0.85 g / cc, which has been used in conventional super-explosives, is generally made in a tower of about 40 to 50 m in a solution of about 97% ammonium nitrate (3% water).

Colostrum explosives are prepared by simply mixing light oil with ammonium fryl nitrate. Conventionally, ammonium fryl nitrate used in superexplosives has a specific gravity of 0.75 to 0.85 g / cc and a diesel oil absorption of 5 to 10%. The explosive speed of ammonium fryl nitrate using this was 2,500 to 3,000 m / sec. The reason why there is a lot of smell in general diesel oil is because there is an aromatic component. In the present invention, in order to remove this smell, distillation to remove volatile matters below 150 ° C. Most of the aromatics are all removed below 100 ° C.

In addition, artificial explosives such as GMB or high-explosives such as TNT or RDX are added to increase the power of the superexplosives, which increases the cost of the superexplosives and reduces safety.

The present invention has been made in view of the above-mentioned problems, and the use of one having a lower specific gravity and higher oil absorption than conventional ammonium fryl nitrate, and the use of diesel fuel having a low odor, have a destructive power without burden of safety or cost. It is to provide a low specific gravity explosives that can increase the power and enable users to use it without smell.

In order to achieve the above object, the present invention is an ultra-explosive powder consisting of an oxidizing agent and a flammable agent, ammonium ripple nitrate having a specific gravity of 0.6 to 0.75 g / cc as an oxidizing agent, a super-explosive powder containing a light oil having a flow rate of 150 ℃ or more as a flammable agent Is done.

Ammonium pryl nitrate as the oxidizing agent is preferably prepared in a tower of about 60 m using an ammonium nitrate solution containing 5-7 wt% of water by pore formation by moisture drying in order to have a lot of pores therein, that is, low specific gravity. Do.

Optionally, the ammonium pryl nitrate may be mixed with an artificial bubble support agent such as glass microballoon (GMB) or plastic microballoon (PMB) perlite in an ammonium nitrate solution, and then sprinkled in a tower to cool and dry to lower the weight ratio.

It is also desirable to coat the anti-caking agent in the process of making ammonium nitrate. Uncoated with this formulation, ammonium fryl nitrate is very hygroscopic (dissolves 118 g per 100 ml of water at 0 ° C.) and readily solidifies. Generally, it is preferable to use 0.05-0.2% by weight of anti-caking agent, and if it is less than 0.05, there is no effect of preventing moisture absorption, and when it is 0.2 or more, the power of explosive is reduced. Acts as a.)

In order to improve the manufacturability and handleability in the manufacture of gunpowder ammonium nitrate, it is most preferred that the screen size be 3.36 mm or less in diameter and 20% or less in diameter. The more thin, the lower the flowability, and the thicker the amount, the weaker it will not mix well with the diesel.

On the other hand, the diesel fuel, which is a combustor, is preferably distilled off by distilling at an initial flow point of 150 ° C. to remove odors.

Ammonium fryl nitrate as the oxidizing agent and diesel oil as the combustor are prepared by mixing in a mixer, and the diesel oil absorption is preferably in the range of 10 to 20%.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. The following Examples are only described to facilitate the practice of the present invention, and are not described to limit the invention.

EXAMPLE

The method of manufacturing the draft explosives of the embodiment is the same, and the first embodiment will be described as follows.

94.3% by weight of ammonium fryl nitrate having a weight ratio of 0.61 to 0.65 was added to the mixer, and the mixture was sputtered while uniformly sprinkling 5.7% by weight of the aromatic aromatic oil.

Note 1) The speed detonation of the above performance is the result of measuring the speed detonation by inserting an ultra-explosive into a 50mm steel pipe and detonating it with a primer.

Note 2) The ballistic ball is a numerical value representing static power. It is a comparison value when TNT is set to 100, and is measured by a ballistic ball tester.

As shown in Examples 1 to 3, the ballistic ball wrapping force is almost no difference, but it can be seen that the deceleration force is higher as the weight ratio is lower. The ultra-explosive powder of the present invention using an ammonium fryl nitrate having a specific weight of 0.61-0.75 has a very good result in speeding and ballistic ball compared with the performance result of Example 4, which is a conventional product.

As described above, the effect of the present invention prepared by using a non-aromatic solvent having a low specific odor by using ammonium fritrate having a specific gravity of 0.6 to 0.75 g / cc and a diesel oil absorption of 10 to 20% and removing the aromatic component is as follows. same.

The stronger the rock, the higher the explosive power of explosive force is needed. In the past, the use of relatively weak rock blasting, such as limestone and sandstone, was difficult. However, the ultra-explosive prepared by the method of the present invention is almost applicable to limestone, sandstone, as well as granite, which is hard rock, and in particular, it has little smell so that it is not inconvenient to use in tunnels.

Claims (4)

In the super explosives consisting of an oxidizing agent and a flammable agent, Said oxidizing agent is ammonium fryl nitrate with a specific gravity of 0.6-0.75 g / cc, and said flammable agent is super oil explosive which has a superoleating point of 150 degreeC or more. The ultra-explosive charge according to claim 1, wherein the ammonium fryl nitrate has a particle size of 3.36 mm or less in diameter and 1.41 mm or less in diameter. The colostrum according to claim 1 or 2, wherein the colostrum is contained 0.05 to 0.20% by weight of an anti-caking agent for preventing solidification of the product. The method of claim 3, wherein the ammonium fryl nitrate is prepared using a method for forming pores by moisture drying or an artificial bubble forming method which adds one selected from the group consisting of Glass Micro Balloon (GMB), Plastic Micro Balloon (PMB) and Perlite. Super explosives characterized by.