Explosive primer and production process

Abstract

The present invention relates to an explosive primer produced using a PETN suspension. The primer is a hybrid high explosive that mixes a molecular explosive with dispersant additives. Its primary feature is its good mixing performance in comparison with conventional pentolite mixtures. The invention also relates to a method for producing the primer.

Description

[0001] EXPLOSIVE PRIMER AND MANUFACTURING PROCESS

[0002] The present invention discloses a primer, booster, or detonator made from a PETN (pentaehtritol tetranitrate) suspension. This primer is a hybrid high explosive, combining a molecular explosive with dispersing additives. Its primary characteristic is its excellent mixing performance compared to traditional pentolite mixtures.

[0003] TECHNICAL FIELD

[0004] Boosters, commonly known as primers, secondary explosives, or detonator-sensitive explosives in blasting applications, are traditionally manufactured with a high-performance explosive mixture called pentolite, which combines high-energy molecular explosives, specifically TNT (trinitrotoluene) and PETN (pentaerythritol tetranitrate). This mixture provides high density, a strong velocity of detonation (VOD), and stable performance, making it widely used to effectively initiate large charges. However, considering environmental and logistical aspects, boosters with alternative formulations have emerged. One example is emulsion-based boosters, such as Powergel offered by the company Oñca. These boosters incorporate emulsified fuel and oxidizer compositions instead of traditional TNT or PETN.Although they have a lower environmental impact and better cost-effectiveness, emulsion-based boosters often have suboptimal density and VOD, which frequently results in inconsistent performance compared to pentolite boosters.

[0005] TNT, in particular, has been the subject of increasing efforts to replace it due to both environmental and geopolitical concerns. Environmentally, its production and use generate toxic waste that can contaminate soil and water, making it a high-risk substance for environmental sustainability. From a geopolitical perspective, TNT is classified as a strategic material and is subject to strict international regulations, which hinders its transport and storage in regions with conflicts or export restrictions. These factors, coupled with advances in alternative formulations, have driven the search for safer, more efficient, and more sustainable options to replace TNT in industrial and mining applications. The present invention addresses this gap or limitation by providing a formulation of a booster based on PETN, combined with selected oxidizers and fuels.This composition achieves a high detonation velocity and density comparable to pentolite-based boosters, providing reliable initiation power without the drawbacks associated with emulsion-based products. This combination of PETN, oxidizers, and fuel offers a balance between high performance and safer operation without TNT, while maintaining the robustness necessary for effective initiation in demanding blasting environments.

[0006] STATE OF THE ART

[0007] Patent AU584884B2 describes a method for a molten explosive composition comprising an inorganic oxidizer, a liquid organic fuel immiscible with water (less than 5% w / w water), a sensitizer (such as PETN), and an emulsifier that forms a water-in-oil emulsion at high temperatures and allows crystallization of the oxidizer at room temperature. The patent describes an emulsion-based phthalate, whereas the present invention uses a PETN-based suspension.

[0008] US patent 5880399 describes a capsule-sensitive molten explosive composition that uses a mixture of sodium perchlorate as an oxidizer and diethylene glycol as a binder, combined with microspheres to enhance its properties. The microspheres serve multiple purposes, such as reducing the critical diameter and impact sensitivity, and helping the composition reach terminal detonation velocity more quickly. The present invention, in contrast, focuses on the use of non-explosive components that become capsule-sensitive after curing, providing a safer manufacturing and handling process than traditional TNT- or PETN-based explosives.

[0009] Patent EP0159171 B1 discloses a molten explosive composition comprising an inorganic oxidizing salt; a water-immiscible organic liquid fuel; less than approximately 5% w / w of the total composition of water or the equivalent amount of water plus a water-miscible liquid; a sensitizer comprising a molecular explosive (which may be PETN); and an emulsifier that allows the formation of a water-in-oil emulsion at an elevated formulation temperature but allows the emulsion to weaken and the inorganic oxidizing salt to crystallize at room temperature to produce a molten composition. Patent EP0159171 B1 uses a water-in-oil emulsion, whereas the present invention uses a PETN suspension as the main base explosive, without TNT.

[0010] US patent 6702909 describes a high-energy explosive containing molten particles. This patent outlines an approach to making emulsion explosives behave more like dynamite by adding a molecular explosive, such as PETN particles. Emulsion phases are easier to handle (and particles can be more easily added and mixed throughout) when they are hot, such as at their formulation temperatures (typically 70°C or higher). This is especially true if the emulsion phases contain waxes as part of the fuel phase, which increase in viscosity upon cooling. However, risks increase when a molecular explosive is added to a hot emulsion phase. For example, PETN has a lower DTA (Differential Thermal Analysis) exotherm of 150°C, which would pose a safety concern if PETN particles were added to a hot emulsion.The present invention, on the other hand, provides a particulate additive that can be safely added to a hot emulsion phase and that imparts greater density and energy to the resulting emulsion explosive.

[0011] Patent application WO 2013082634 discloses a non-detonable base charge explosive formulation for use in a detonator, comprising a solution containing a plurality of salts and a binder. The salts include sodium nitrate and calcium nitrate with varying particle size distributions. The application also discloses an explosive composition comprising a mixture of a plurality of salts and a binder, and a combination of sodium perchlorate and nanoporous silicon. The salts include sodium nitrate and calcium nitrate. The sodium perchlorate is granular with particles of varying sizes, similar sizes, or a bimodular particle size distribution. The nanoporous silicon is mixed with or coated with an oxidant.The composition of this invention comprises a combination of sodium perchlorate and nanoporous silicon, including at least one additive selected from the following: aluminum powder, PETN, RDX (cyclotrimethylenenitramine or cyclonite), and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine). In this invention, the reaction between the salts and the combination of sodium perchlorate and nanoporous silicon is completed in 1 to 30 minutes. DESCRIPTION OF THE INVENTION.

[0012] The present invention discloses a phmador, also called a booster or primer, manufactured from a PETN suspension. This phmador is a hybrid high explosive, combining a molecular explosive with dispersing additives. Its primary characteristic is its superior mixing performance compared to traditional pentolite mixtures. The present invention also discloses a manufacturing process for this phmador.

[0013] The phmador described here is an explosive comprising salts in concentration ranges of 15 to 40% w / w dissolved in water.

[0014] The phmador described here comprises a fuel, in a concentration from 1% to 20% w / w (of the liquid and solid type), where the fuel exhibits thermoplastic characteristics.

[0015] An oxygen balance range between +5% and -35% is preferred.

[0016] Oxygen balance is a stoichiometric measure that indicates the difference between the oxygen available in the oxidizers of an explosive mixture and the oxygen required by the fuels for a complete reaction. Expressed as a percentage, it determines whether the reaction is balanced, with an excess, or a deficit of oxygen, impacting efficiency and the byproducts generated. It is measured as the amount, expressed as a percentage by weight, released as a result of the complete conversion of the explosive material to CO2, H2O, SO2, AlO2, etc. If there is insufficient oxygen for the complete oxidation reaction, the compound is said to have a negative oxygen balance. Conversely, if the reaction releases an excess of oxygen, the compound is said to have a positive oxygen balance.

[0017] Commercial explosives must have a near-zero oxygen balance to minimize the amount of toxic gases, particularly carbon monoxide and nitrous gases, present in the fumes. Balanced combustion ensures efficient explosive performance. The exception is molecular explosives (used as initiators or boosters), composed of oxidizing and combustible compounds, which are characterized by very negative oxygen balances (less than approximately -25%). The primer described in the present invention is an explosive that does not contain density modifiers.

[0018] The components of the invention and their concentration in percentage by weight are indicated in Table 1 below.

[0019] Table 1

[0020]

[0021] Table 2 below shows more specifically some of the dispersing additive components of the invention and their concentration in percentage by weight.

[0022] Table 2

[0023]

[0024] The emulsifiers used in the present invention will depend on the HLB (hydro-lipophilic balance). The emulsifiers used in the present invention have an HLB between 3.5 and 6.0, among which we can mention the PIBSA type emulsifiers and mono-oleates, among others.

[0025] The main characteristics of the explosive primer of the present invention are described in Table 3 below.

[0026] Table 3

[0027] >

[0028]

[0029] Energy is the amount released during detonation, including heat and mechanical energy.

[0030] EXPLOSIVE PRIMER MANUFACTURING PROCESS

[0031] The present invention also describes a manufacturing process for the explosive primer described above.

[0032] A semi-continuous manufacturing process is described. The raw materials that serve as a suspension for PETN are mixed at high temperatures in mixing processes.

[0033] This requires the following equipment:

[0034] 1. Atmospheric pressure mixing tank with horizontal pendulum agitator (around 90°)

[0035] 2. Wax mixture storage tank. With a dosing pump to the mixing tank (1). 3. Heated dispersing additive storage tank, maintained at a temperature between 85 and 90°C. With a dosing pump to the mixing tank (1). 4. PETN dosing tank (gravity addition). This addition is continuous and controlled, according to the RPM setting of the mixing tank agitator. For better homogenization and dispersion of the PETN, continuous and controlled addition is necessary, thus inhibiting the formation of lumps or agglomerations. The product is formed with optimal dispersion in less time.

[0036] The operating ranges for online manufacturing are:

[0037] Density (g / ml): 1.40 - 1.55

[0038] Temperature (°C): 85 - 92

[0039] Average manufacturing time: 50 to 70 minutes

[0040] The manufacturing process of the explosive phmador comprises the following stages:

[0041] a. Add the components to the mixing tank with agitation.

[0042] -an oxidant at a concentration between 15% and 40% w / w,

[0043] -a fuel in a concentration between 1% and 20% w / w,

[0044] -an explosive in a concentration between 30% and 70% w / w, and

[0045] -an additive in a concentration between 1% and 20% w / w;

[0046] b. homogenize the mixture from step (a);

[0047] c. add the PETN explosive to the homogenized mixture of (b);

[0048] d. stir the mixture obtained in step (c);

[0049] e. Let the mixture cool to a temperature of 40°C or lower;

[0050] f. dosing and packaging the product. Calcium carbonate is added in stage (c) in a range between 0.1 to 2% w / w to inhibit CO2 generation.

[0051] In the primer manufacturing process, the oxidizer is selected from nitrates and / or perchlorates. The nitrate is selected from ammonium nitrate, sodium nitrate, and calcium nitrate, and the perchlorate is selected from ammonium perchlorate, sodium perchlorate, calcium perchlorate, and potassium perchlorate.

[0052] In the manufacturing process of the prime mover, the fuel is selected from diesel, fuel oil, mineral oils, and metal powders.

[0053] In the manufacturing process of the primer, the fuel is selected from metallic powders such as aluminum, copper, or iron.

[0054] In the manufacturing process of the primer, the explosive is pentaerythritol tetranitrate (PETN).

[0055] In the primer manufacturing process, the additive is selected from water, oils, emulsifiers, waxes, calcium carbonate, or mixtures thereof.

[0056] In the manufacturing process of the primer, the additive is selected from paraffin wax and / or microcrystalline wax.

[0057] In the primer manufacturing process, the emulsifying additive has a hydrolipophilic balance (HLB) between 3.5 and 6.0. The emulsifier is selected from polyisobutenyl succinic anhydride (PIBSA) and mono-oleates.

[0058] In the manufacturing process of the primer, step (b) is performed at a temperature of 85 to 92 °C.

[0059] In the manufacturing process of the primer, step (c) is performed at a temperature of 85 to 92 °C.

[0060] In the manufacturing process of the primer, the mixture obtained in step (c) must be stirred until a homogeneous mixture with a density between 1.40 g / ml and 1.55 g / ml is obtained. APPLICATION EXAMPLES

[0061] By way of example and without limiting the invention to these, the following application examples are detailed:

[0062] Example 1

[0063] An explosive mixture was prepared, consisting of different compounds, oxidizers, and molten liquid and solid fuels as shown in Table 4-1 below:

[0064] Table 4-1: Example 1

[0065]

[0066] Example 2

[0067] Example 2 was prepared using the components as indicated in Table 4-2:

[0068] Table 4-2: Example 2

[0069]

[0070] The product obtained by the present invention showed the following characteristics as indicated in Table 5 and Table 6 compared with pentolite:

[0071] Physcochemical Characteristics:

[0072] Physicochemical characteristics similar to pentonite, that is, density, consistency (solid), and resistance to attack by water.

[0073] Table 5

[0074]

[0075] Ballistic Characteristics:

[0076] Thermodynamic properties similar to pentolite, such as: oxygen balance, detonation velocity, detonation pressure, detonation heat, energy released, gas volume.

[0077] Table 6

[0078]

[0079] MANUFACTURING EXAMPLE

[0080] An example of the explosive primer manufacturing procedure was carried out according to the composition of Example 1. In a mixing tank, mixtures of (melted) waxes—paraffinic and microcrystalline wax—were added in a 70 / 30 ratio and a concentration of 7% w / w. Subsequently, 23% w / w ammonium nitrate was added as an oxidizer, along with 5% w / w water and 4% w / w mineral oil as an emulsified fuel. The mixture was homogenized at 85°C. 1% w / w calcium carbonate was added to neutralize an acidity of approximately 0.34. Then, 60% w / w PETN was added in a controlled manner, according to the agitation of the mixing tank, achieving a density of 1.44 g / ml. The mixture was allowed to cool for 30 minutes and finally dosed to the desired weight of the final product.

[0081] Table 7 shows the PETN suspension-based explosive primer that has similar yields to a composition containing TNT.

[0082] Table 7

[0083] > >

[0084] > >

[0085]

[0086] Table 7 compares the PETN suspension-based explosive primer with one using TNT. Unlike a molten mixture, the PETN suspension consists of solid particles dispersed in a matrix. Although the density of PETN could cause it to settle, the presence of waxes and the cooling process prevent sedimentation, keeping the particles in suspension.

[0087] Table 7, which compares detonation velocity and detonation pressure, reveals that the TNT-free formulation of this application exhibits a performance profile remarkably similar to that of conventional explosives containing TNT. These results show that the present formulation offers a safe and effective alternative to traditional explosives, without compromising performance.

[0088] The comparative analysis of Table 7, focused on detonation speed and pressure, indicates that the proposed formulation, based on a PETN suspension, achieves performance levels comparable to traditional explosives containing TNT.

[0089] Not including TNT is due to high environmental requirements, as well as the continuous geopolitical variables in obtaining its supply.

[0090] In conclusion, a composition of explosive phmador based on PETN suspension is proposed, with the advantage of not including TNT, and which presents similar performance to the traditional pentolite used for the manufacture of phmadores.

Claims

CLAIMS 1. An explosive primer comprising the following components: a. an oxidant at a concentration between 15% and 40% w / w, b. a fuel in a concentration between 1% and 20% w / w, c. an explosive in a concentration between 30% and 70% w / w, d. an additive in a concentration between 1% and 20% w / w.

2. The explosive primer according to claim 1, wherein the oxidizer is selected from nitrates and / or perchlorates.

3. The explosive primer according to claim 2, wherein the nitrate is selected from ammonium nitrate, sodium nitrate, and calcium nitrate.

4. The explosive primer according to claim 2, wherein the nitrate is selected from ammonium nitrate, sodium nitrate, and calcium nitrate.

5. The explosive primer according to claim 1, wherein the fuel is selected from diesel, fuel oil, mineral oils and metal powders.

6. The explosive primer according to claim 5, wherein the metal powders are selected from aluminum powder, copper powder, or iron powder.

7. The explosive primer according to claim 1, wherein the explosive is pentaerythritol tetranitrate (PETN).

8. The explosive primer according to claim 1, wherein the additive is selected from water, oils, emulsifiers, waxes, calcium carbonate, or mixtures thereof.

9. The explosive primer according to claim 8, wherein the additive is selected from paraffin wax and / or microcrystalline wax.

10. The explosive primer according to claim 8, wherein the emulsifying additive has a hydrolipophilic balance (HLB) between 3.5 and 6.

0.

11. The explosive primer according to claim 10, wherein the emulsifier is selected from polyisobutenyl succinic anhydride (PIBSA) and mono oleates.

12. A manufacturing process for the explosive primer of claim 1, comprising the following steps: a. Add the following components to the mixing tank with agitation - an oxidant at a concentration between 15% and 40% w / w, -a fuel in a concentration between 1% and 20% w / w, -an explosive in a concentration between 30% and 70% w / w, and -an additive in a concentration between 1% and 20% w / w; b. homogenize the mixture from step (a); c. add the PETN explosive to the homogenized mixture of (b); d. stir the mixture obtained in step (c); e. Allow the mixture to cool to a temperature of 40°C or less; f. Dosage and package the explosive primer.

13. The manufacturing process of the explosive primer according to claim 12, wherein the oxidizer is selected from nitrates and / or perchlorates.

14. The manufacturing process of the explosive primer according to claim 13, wherein the nitrate is selected from ammonium nitrate, sodium nitrate, and calcium nitrate.

15. The manufacturing process of the explosive primer according to claim 13, wherein the perchlorate is selected from ammonium perchlorate, sodium perchlorate, calcium perchlorate, and potassium perchlorate.

16. The manufacturing process of the explosive primer according to claim 12, wherein the fuel is selected from diesel, fuel oil, mineral oils, and metal powders.

17. The manufacturing process of the explosive primer according to claim 16, wherein the metal powders are selected from aluminum powder, copper powder, or iron powder.

18. The manufacturing process of the explosive primer according to claim 12, wherein the explosive is pentaethtol tetranitrate (PETN).

19. The manufacturing process of the explosive primer according to claim 12, wherein the additive is selected from water, oils, emulsifiers, waxes, calcium carbonate, or mixtures thereof.

20. The manufacturing process of the explosive primer according to claim 19, wherein the additive is selected from paraffin wax and / or microcrystalline wax.

21. The manufacturing process of the explosive primer according to claim 19, wherein the emulsifying additive has a hydrolipophilic balance (HLB) between 3.5 and 6.

0.

22. The manufacturing process of the explosive primer according to claim 21, wherein the emulsifier is selected from polyisobutenyl succinic anhydride (PIBSA) and mono oleates.

23. The manufacturing process of the explosive primer according to claim 12, wherein in step (a) the components are added in an atmospheric pressure mixing tank with a horizontal pendulum-type agitator.

24. The manufacturing process of the explosive primer according to claim 12, wherein step (b) is carried out at a temperature of 85 to 92 °C.

25. The manufacturing process of the explosive primer according to claim 12, wherein step (c) is carried out at a temperature of 85 to 92 °C.

26. The manufacturing process of the explosive primer according to claim 12, wherein the mixture obtained in step (c) is also stirred until a homogeneous mixture with a density between 1.40 g / ml and 1.55 g / ml is obtained.

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