Exploding Thermite Compositions and Methods

This application claims the benefit of U.S. Provisional Patent Application No. 63/633,577, filed Apr. 12, 2024, titled “EXPLODING THERMITE COMPOSITIONS AND METHODS,” which is incorporated herein by reference in its entirety, including but not limited to those portions that specifically appear hereinafter, the incorporation by reference being made with the following exception: In the event that any portion of the above-referenced provisional patent application is inconsistent with this application, this application supersedes the above-referenced provisional patent application.

This disclosure was made with government support under Contract 693JK320C000005—Default Classification of Explosives (Thermite), Project No. PH957-20-0072, awarded by PIPELINE AND HAZARDOUS MATERIALS SA, Acquisition Services Division. The government has certain rights in the invention.

This disclosure relates generally to compositions including metals and metal oxides and more particularly to explosive thermite compositions.

Explosives have a wide range of civilian, military, and industrial applications. Explosives may be utilized in military and defense applications as a component in numerous types of weapons. Explosives may be an important component of mining and quarrying operations, and may be utilized for rock blasting, controlled demolition, tunneling, and so forth. Some types of explosives are efficient and cost-effective for performing demolition and construction, including building demolition, bridge removal, road excavation, tunnel excavation, and so forth. Explosives may be utilized in the oil and gas industries for well perforation and fracking. Explosives may be utilized for solid rocket propellants and ejection charges to missiles, vehicles, and parachutes. Explosives may additionally be utilized in fireworks and pyrotechnics for entertainment, military applications, and signaling applications.

Traditional explosives are associated with numerous inefficiencies, drawbacks, and safety risks. Many traditional explosives are sensitive to shock, heat, and friction, and this makes them dangerous to transport and manage. Additionally, over time, traditional explosives may undergo chemical degradation that makes the explosive sensitive or ineffective. Further, moisture absorption can negatively impact the effectiveness of some types of explosives. Several classes of traditional explosives must be stored in temperature-controlled environments to prevent degradation or accidental detonation.

What is needed are improved compositions and methods for explosives with improved shelf stability and safety during manufacture, storage, and transport. In view of the foregoing, described herein are systems, compositions, and methods for explosive thermites. The systems, compositions, and methods described herein provide explosives with improved shelf stability, efficiency, and safety.

Disclosed herein are compositions and methods for reactive thermites. Specifically described herein are thermite compositions including specific combinations of metal and metal oxide powders to produce an explosive. The explosive thermite compositions described herein may activated when the metal and metal oxide powders are in an unconsolidated loose powder form, and they may be prepared and stored with or without additional additives. The compositions and methods described herein may be utilized for propellants, pyrotechnics, explosives, initiation trains, cutting torches, tools, devices, and so forth.

Thermites are compositions including a metal powder and a metal oxide. When ignited, thermite compositions may undergo highly exothermic redox reactions, which may produce extreme heat and molten metal. Thermite compositions may burn at temperatures exceeding 2,500° C. and may be utilized for welding, metal cutting, and military applications. Thermites produce much higher levels of thermal flux than traditional explosives, propellants, and pyrotechnics. Additionally, thermites produce molten metal that may melt or cut through containment and cause combustion of most organic materials.

Because thermites are highly reactive and may burn at exceedingly high temperatures, thermite compositions are traditionally not used as explosives for propellants, pyrotechnics, explosives, initiation trains, cutting torches, tools, devices, and so forth. However, the thermite compositions described herein may be ignited to produce an explosive reaction at lower temperature and may thus be utilized as an explosive in various implementations.

Described herein are specific compositions of thermites that exhibit an explosion hazard upon thermite reaction activation. The thermite compositions described herein exhibit long-term chemical stability and thus exhibit a longer shelf-life than traditional explosive compositions. The thermite compositions described herein exhibit improved thermal stability and resistance to decomposition at temperatures that are known to decompose and destroy traditional organic explosive compositions. The thermite compositions described herein exhibit electrical conductivity. The thermite compositions described herein exhibit insensitivity to various stimuli that are known to degrade traditional explosives, and specifically exhibit insensitivity to impact, friction, electrostatic discharge, heat, flame, and shock. The thermite compositions described herein exhibit elevated reaction rates and low explosive power (i.e., reduced fragmentation potential), and additionally exhibit survivability and usability after exposure to extreme environments. The thermite compositions described herein may be stored as an unconsolidated powder in loose form, in a pressed pellet form, in a housing, or in a casing. The thermite compositions described herein may be prepared with or without one or more additives, which may be utilized to control or moderate the rate of reaction of the thermite composition for various applications.

In the following description of the disclosure, reference is made to various tables, which form a part hereof, and in which is shown by way of illustration specific implementations in which the disclosure may be practiced. It is understood that other implementations may be utilized, and structural changes may be made without departing from the scope of the disclosure.

For the purposes of promoting an understanding of the principles in accordance with the disclosure, reference will now be made to various embodiments, and specific language will be used to describe those embodiments. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the disclosure made herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the disclosure.

Before the present systems, compositions, and methods for thermites with an explosion hazard are disclosed and described, it is to be understood that this disclosure is not limited to the particular configurations, process steps, and materials disclosed herein as such configurations, process steps, and materials may vary somewhat. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the disclosure will be limited only by the appended claims and equivalents thereof.

In describing and claiming the disclosure, the following terminology will be used in accordance with the definitions set out below.

It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

As used herein, the terms “comprising,” “including,” “containing,” “characterized by,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps.

As used herein, the phrase “consisting of” and grammatical equivalents thereof exclude any element, step, or ingredient not specified in the claim.

As used herein, the phrase “consisting essentially of” and grammatical equivalents thereof limit the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic or characteristics of the claimed disclosure.

As used herein, the phrase “thermite reaction” refers to a reaction wherein the unoxidized metal reactant is oxidized to a metal oxide product and the metal oxide reactant is reduced to an unoxidized metal product, releasing energy/heat.

Referring now to the figures,is a schematic block diagram of a methodfor preparing an explosive thermite composition and igniting an explosive redox reaction.

The methodincludes preparing a thermite compositionthat includes a metal oxide powderand a metal powder. The thermite compositionmay optionally additionally include an additive. The components of the thermite composition, including the metal oxide powder, the metal powder, and the optional additive, may form a homogenous combination. The methodincludes ignitionof the thermite compositionto output an explosive redox reaction.

The metal oxide powderis a compound formed when a metal reacts with oxygen. The metal oxide powdermay include a metal oxide that will readily undergo a reduction with aluminum or another reducing agent. The metal oxide powdermay include one or more of ferric oxide (FeO), black iron oxide (FeO, also known as iron (II,III) oxide), cupric oxide (CuO), bismuth trioxide (BiO), molybdenum trioxide (MoO), chromium trioxide (CrO), iron (II,III) oxide (FeO), manganese dioxide (MnO), nickel (II) oxide (NiO), tin (IV) oxide (SnO), cuprous oxide (CuO), iron (III) oxide (FeO), chromium (III) oxide (CrO), manganese (IV) oxide (MnO), titanium dioxide (TiO), boron trioxide (BO), or silicon dioxide (SiO).

The metal oxide powdermay comprise a fine powder having a particle size from about one μm to about 5 μm, within a size tolerance of 15%. The metal oxide powdermay comprise a moderately sized powder comprising a particle size from about 50 μm to about 70 μm, within a size tolerance of 15%. The metal oxide powdermay comprise a coarse powder comprising a particle size from about 150 μm to about 200 μm, within a size tolerance of 15%. The metal oxide powdermay comprise nanoparticles comprising a particle size less than one μm. The metal oxide powdermay comprise a particle size from about one μm to about 200 μm in various implementations.

The metal powderis a reactive metal that may serve as a reducing agent in the explosive redox reaction. The metal powdermay include one or more of aluminum (Al), magnesium (Mg), calcium (Ca), zirconium (Zr), or titanium (Ti). The metal powdermay include magnalium, which includes a combination of magnesium and aluminum. The magnalium may include a 50/50 ratio of magnesium and aluminum within a tolerance threshold of 15 percent. The metal powdermay include a combination of magnesium and aluminum in varying ratios. The metal powdermay include a combination of magnesium, aluminum, and titanium.

The metal powdermay comprise a fine powder having a particle size from about one μm to about 5 μm, within a size tolerance of 15%. The metal powdermay comprise a moderately sized powder comprising a particle size from about 50 μm to about 70 μm, within a size tolerance of 15%. The metal powdermay comprise a coarse powder comprising a particle size from about 150 μm to about 200 μm, within a size tolerance of 15%. The metal powdermay comprise nanoparticles comprising a particle size less than one μm. The metal powdermay comprise a particle size from about one μm to about 200 μm in various implementations.

The thermite compositionmay be prepared with or without the additive. The additivemay be included to control properties of the thermite composition, including reaction rate, burn temperature, ignition temperature, efficiency and so forth. The additivemay enhance or decrease the heat output by the explosive redox reaction. The additivemay aid in stabilizing the thermite compositionor adjusting a temperature for the ignitionof the explosive redox reaction. The additivemay include one or more of an oxidizer, a stabilizer, a catalyst, a fuel additive, a reducing agent, a control agent, a binder, a polymer, a nitrate, a chlorate, a perchlorate, an oxide, a peroxide, a superoxide, a metal, or a metal alloy.

The additivemay include polytetrafluoroethylene (PTFE or Teflon®), which is an ingredient utilized in pyrotechnics and flares. The additivemay include molybdenum trioxide (MoO), which is a metal oxide utilized in thermite mixtures. The additivemay include sodium nitrate (NaNO), which is a weak nitrate that is slower acting than other nitrates like potassium nitrate or barium nitrate. The additivemay include calcium peroxide (CaO), which is an oxidizer utilized in pyrotechnic mixtures.

The additivemay include an oxidizer to increase the amount of oxygen available in the explosive redox reactionand enhance the ability of the thermite compositionto burn at higher temperatures or with more energy. The additivemay include one or more of copper (II) oxide (CuO), chromium (III) oxide (CrO), or manganese (IV) oxide (MnO). The additivemay include a catalyst to speed up the explosive redox reactionwithout being consumed. The additivemay include one or more of iron (Fe) or magnesium (Mg). The additivemay include a reducing agent to lower the activation energy of the explosive redox reaction. The additivemay include one or more of zinc (Zn) or aluminum (Al).

The additivemay include a stabilizer to prevent excessive reactivity or to ensure a controlled burn during the explosive redox reaction. The additivemay include one or more of silica (SiO) or boron (BO). The additivemay include a control agent to adjust the reaction speed of the explosive redox reaction. The additivemay include one or more of calcium carbonate (CaCO) or potassium nitrate (KNO).

The additivemay comprise a fine powder having a particle size from about one μm to about 5 μm, within a size tolerance of 15%. The additivemay comprise a moderately sized powder comprising a particle size from about 50 μm to about 70 μm, within a size tolerance of 15%. The additivemay comprise a coarse powder comprising a particle size from about 150 μm to about 200 μm, within a size tolerance of 15%. The additivemay comprise nanoparticles comprising a particle size less than one μm. The additivemay comprise a particle size from about one μm to about 200 μm in various implementations.

Each of the metal oxide powder, the metal powder, and the additivemay be provided in a powder form. In some cases, the additiveis not provided in a powder form. The metal oxide powderand the metal powdermay be provided in a powder comprising a variety of particle sizes. The metal oxide powderand the metal powdermay comprise particle sizes from about one μm to about five μm.

The metal oxide powder, the metal powder, and the optional additiveare combined to form a homogenous combination. The components,,may be homogenously combined utilizing any suitable method. In some cases, the homogenous combinationis prepared according to the methoddescribed in connection with. In some cases, the homogenous combinationis prepared by mixing the components,,in an electrically conductive container that is tumbled end-over-end. In some cases, the homogenous combinationis prepared by utilizing a whisk shaker ball to encourage breakup of powder agglomerates. In some cases, the homogenous combinationis prepared utilizing a stirring mixer or blender.

The metal oxide powder, metal powder, and optional additivemay be combined by utilizing a mixer comprising an electrically conductive plastic container. The components,,are disposed within the electrically conductive plastic container such that the electrically conductive plastic container is up to 50% full by volume, or up to about 70% full by volume. The electrically conductive plastic container may be remotely tumbled end-over-end every three to four second (i.e., fifteen rotations per minute) for up to 15-50 minutes. The electrically conductive plastic container may comprise a whisk shaker ball disposed therein to encourage breakup of powder agglomerates during mixing. This method may achieve a homogeneous mixture without significantly reducing the initial particle sizes of the metal oxide powder, the metal powder, or the optional additive.

The thermite compositionmay include loose powders that are unconsolidated. The thermite compositionmay be pressed or consolidated to control or moderate the rate of the explosive redox reaction.

The thermite compositionmay comprise a rise time ranging from about 0.2 milliseconds to about 5 milliseconds, within a time tolerance of 15%. The thermite compositionmay produce an explosion hazard upon thermite reaction activation with a slow deflagration having a rise time of about 30 milliseconds or more.

The ignitionincludes achieving a sufficiently high temperature to overcome the activation energy required to initiate the explosive redox reaction. The ignitionmay include applying an external heat source capable of rapidly reaching a sufficiently high temperature. Thermites are typically difficult to ignite because most traditional thermite compositions have a high activation temperature that may be in excess of 2,500° C.

The ignitionmay include utilization of one or more of a magnesium ribbon, a ferrocerium, an electrical ignition, a sparkler fuse, an electrical heating element, pyrogen igniter, a flame-producing igniter, a chemical reaction. The ignitionmay additionally or alternatively include a stimuli such as impact, friction, electrostatic energy discharge. The ignitionmay include utilization of a black powder bag igniter. The ignitionmay generate a temperature from about 1000° C. to about 1500° C. The ignitionmay generate a temperature of about 1200° C.

Without additives, the thermite compositionmay require an ignition or heating temperatures greater than or equal to 400° C. to activate the explosive redox reaction. Once activated, the explosive redox reactionis self-sustaining and may rapidly output heat in excess of 1000° C.

The explosive redox reactionis an oxidation-reduction reaction where a first component is reduced (i.e., gains electrons) and another component is oxidized (i.e., loses electrons). In the explosive redox reaction, the metal oxide powderacts as the oxidizing agent and the metal powderacts as the reducing agent.

is a schematic block diagram of a methodof preparing a thermite composition. The methodincludes preparing a homogenous combination comprising ferric oxide (FeO)and magnalium (MgAl), which comprises a 50/50 combination of magnesium and aluminum within a ratio tolerance of about 10%. The thermite compositionmay optionally include an additive. The thermite compositionexhibits unexpectedly good results as an explosive to generate the explosive redox reaction.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnalium. The thermite compositionmay comprise from about 25 wt. % to about 90 wt. % the ferric oxide. The magnaliummay comprise a particle size from about one μm to about five μm. The ferric oxidemay comprise a purity in excess of 98% and a particle size from about one μm to about five μm. The thermite compositionmay comprise a fine, red powder when formed in a homogenous combination.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnalium. The thermite compositionmay comprise from about 20 wt. % to about 80 wt. % the ferric oxide. The thermite compositionmay comprise polytetrafluoroethylene (PTFE or Teflon®) powder as the additive. The magnaliummay comprise a particle size from about one μm to about five μm. The ferric oxidemay comprise a purity in excess of 98% and a particle size from about one μm to about five μm. The thermite compositionmay comprise a fine, red powder when formed in a homogenous combination. The PTFE additivemay comprise a particle size from about six μm to about nine μm. The thermite compositionmay comprise a fine, red powder when formed in the homogenous combination.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnalium. The thermite compositionmay comprise from about 20 wt. % to about 80 wt. % the ferric oxide. The thermite compositionmay comprise sodium nitrate (NaNO) powder as the additive. The magnaliummay comprise a particle size from about one μm to about five μm. The ferric oxide may comprise a purity in excess of 98% and a particle size from about one μm to about five μm. The thermite compositionmay comprise a fine, red powder when formed in a homogenous combination. The sodium nitrate additivemay comprise a purity in excess of 98% and a particle size less than 50 μm. The thermite compositionmay comprise a fine, red powder when formed in the homogenous combination.

is a schematic block diagram of a methodof preparing a thermite composition. The methodincludes preparing a homogenous combination comprising cupric oxide (CuO)and magnalium (MgAl), which comprises a 50/50 combination of magnesium and aluminum within a ratio tolerance of about 10%. The thermite compositionmay optionally include an additive. The thermite compositionexhibits unexpectedly good results as an explosive to generate the explosive redox reaction.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnaliumand from about 25 wt. % to about 90 wt. % the cupric oxide. The thermite compositionmay include from about 2 wt. % to about 40 wt. % polytetrafluoroethylene (PTFE or Teflon®) powder as the additive. The magnaliummay comprise a particle size from about one μm to about five μm. The cupric oxidemay comprise a purity in excess of 99% and may comprise a particle size from about one μm to about five μm. The PTFE additivemay comprise a particle size from about six μm to about nine μm. The thermite compositionmay comprise a fine, dark gray powder when formed in a homogenous combination.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnaliumand from about 25 wt. % to about 90 wt. % the cupric oxide. The thermite compositionmay include from about 2 wt. % to about 40 wt. % sodium nitrate (NaNO) powder as the additive. The magnaliummay comprise a particle size from about one μm to about five μm. The cupric oxidemay comprise a purity in excess of 99% and may comprise a particle size from about one μm to about five μm. The sodium nitrate additivemay comprise a purity in excess of 98% and may comprise a particle size less than 50 μm. The thermite compositionmay comprise a fine, dark gray powder when formed in a homogenous combination.

The thermite compositionmay comprise from about 10 wt. % to about 70 wt. % the magnaliumand from about 25 wt. % to about 90 wt. % the cupric oxide. The thermite compositionmay include from about 2 wt. % to about 40 wt. % calcium peroxide (CaO) as the additive. The magnaliummay comprise a particle size from about one μm to about five μm. The cupric oxidemay comprise a purity in excess of 99% and may comprise a particle size from about one μm to about five μm. The calcium peroxide additivemay comprise a purity in excess of 80% and may comprise a particle size less than 50 μm. The thermite compositionmay comprise a fine, dark gray powder when formed in a homogenous combination.

is a schematic block diagram of a methodof preparing a thermite composition. The methodincludes preparing a homogenous combination comprising bismuth trioxide (BiO)and aluminum (Al). The thermite compositionmay optionally include an additive. The thermite compositionexhibits unexpectedly good results as an explosive to generate the explosive redox reaction.

The thermite compositionmay comprise from about 2 wt. % to about 40 wt. % the aluminum. The thermite compositionmay comprise from about 15 wt. % to about 95 wt. % the bismuth trioxide. The aluminummay comprise a purity in excess of 99% and a particle size from about one μm to about five μm. The thermite compositionmay comprise a fine, off-white powder when formed in a homogenous combination.

is a schematic block diagram of a methodof preparing a thermite composition. The methodincludes preparing a homogenous combination comprising bismuth trioxide (BiO)and titanium (Ti). The thermite compositionmay optionally include an additive. The thermite compositionexhibits unexpectedly good results as an explosive to generate the explosive redox reaction.