Title:
Self-remediating projectile
Kind Code:
A1


Abstract:
The invention provides a self-remediating projectile, i.e., an environmentally-remediating bullet, slug, shot, missile, or other ballistic projectile. An environmental remediation agent (e.g., a calcium or magnesium sulfide, phosphate, or similar material), preferably in combination with a water-soluble or biodegradable polymer, acts as a coating for a conventional projectile, rendering it less water soluble and, hence, less prone to corrosion. Also provided are a method of making a self-remediating projectile, an environmentally remediating target, and a method of remediating an area polluted with spent ammunition.



Inventors:
Hurley, Peter J. (West Yorkshire, GB)
Application Number:
10/998220
Publication Date:
09/29/2005
Filing Date:
11/26/2004
Assignee:
Solucorp Industries, Ltd.
Primary Class:
Other Classes:
588/313
International Classes:
F42B12/74; F42B12/80; F42B30/00; F42B30/02; (IPC1-7): F42B30/00
View Patent Images:
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Primary Examiner:
MCDONOUGH, JAMES E
Attorney, Agent or Firm:
Lewis Roca Rothgerber Christie LLP (Glendale, CA, US)
Claims:
1. A self-remediating metal projectile.

2. A self-remediating metal projectile according to claim 1, comprising a bullet, shot, slug, shell, pellet, fiber, foil, or missile.

3. A self-remediating metal projectile according to claim 1, wherein the metal projectile is comprised of one or more metals, alloys, or composites.

4. A self-remediating metal projectile according to claim 1, wherein the metal projectile comprises one or more metals from the group consisting of lead, antimony, bismuth, chromium, cobalt, copper, nickel, tin, tungsten, tantalum, uranium, iron, or one or more alloys or composites thereof.

5. A self-remediating metal projectile according to claim 1, comprising a metal projectile coated with an environmental remediation agent comprising one or more components of capable of reducing the aqueous solubility of the metal projectile.

6. A self-remediating metal projectile according to claim 1, comprising a metal projectile and a passivating coating formed thereon after the projectile is fired.

7. A self-remediating metal projectile according to claim 1, comprising a metal projectile coated with an integrated fixation system.

8. A self-remediating metal projectile according to claim 7, wherein the integrated fixation system is at least as flexible as the metal forming the metal projectile.

9. A self-remediating metal projectile according to claim 1, comprising a metal projectile having an integrated fixation system coated thereon, wherein the metal projectile has a surface adapted to facilitate strong adherence between the integrated fixation system and the metal projectile.

10. A method for manufacturing a self-remediating projectile, comprising: tumble rolling a metal projectile in a mixture of organic solvent, remediation agent, and water-soluble and/or biodegradable polymer; and drying the projectile.

11. A method according to claim 10, wherein the organic solvent comprises a mixture of ethyl acetate and propanol.

12. A method according to claim 10, wherein the polymer comprises a tris-capped copolymer of methyl acrylate and acrylic acid.

13. A method according to claim 10, wherein the remediation agent comprises a 3:2:1 weight-to-weight mixture of calcium sulfide, calcium carbonate, and calcium phosphate.

14. A method according to claim 10, wherein the remediation agent comprises one or more of calcium or magnesium sulfide, phosphate, hydroxide, carbonate, oxide, or apatite;, di-calcium hydrogen phosphate; calcium di-hydrogen phosphate; triple super phosphate; dolomite; phosphoric acid; and/or mixed calcium-magnesium adducts thereof.

15. A method of remediating an area contaminated with spent ammunition, comprising: shooting clean the area with self-remediating ammunition.

16. A method according to claim 15, wherein the self-remediating ammunition contains an excess of one or more remediation agents.

17. A method according to claim 15, further comprising utilizing clay sporting pigeons coated or treated with one or more remediation agents.

18. An environmentally remediating target, comprising: a clay sporting pigeon coated or otherwise treated with at least one environmental remediation agent.

19. An environmentally remediating target according to claim 18, wherein the at least one environmental remediation agent is contained in a polymer binder.

20. A method of remediating an area contaminated with spent ammunition, comprising: shooting clean the area using self-remediating ammunition and clay sporting pigeons treated with at least one environmental remediation agent.

Description:

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Patent Application No. 60/525,253, filed Nov. 26, 2003, and U.S. Provisional Patent Application No. 60/540,291, filed Jan. 29, 2004. The entire contents of both applications are incorporated by reference herein.

FIELD OF THE INVENTION

This invention is directed to ballistic projectiles and their environmental remediation, and related products and materials.

BACKGROUND OF THE INVENTION

The solubility of lead in water (plumbo-solvicity) is a known phenomenon. Pure lead in soft water will yield concentrations of soluble lead levels of above 0.75 mg/litre at pH 7.5 within days to weeks. (FIG. 1.) Lead-antimony alloys will dissolve at a much faster rate and achieve much higher levels of soluble lead owing to Redox reactions of the lead and antimony present in the alloy. (FIG. 2.)

Lead-antimony alloys are extensively used for ballistics applications such as bullets and shot. Such lead alloy usage is in the region of 200-300,000 tons per annum worldwide. When bullets or shot are fired on ranges they can, under adverse conditions, give rise to significant pollution through the solublisation and corrosion of the lead-antimony alloy in a concentrated area. The costs involved in the removal of this pollution are substantial. Remediation might require the site to be acid-washed or the application of remediating agents to the whole site.

To avoid this pollution, others have attempted to coat lead ammunition products with impermeable inert barriers to the surface of the metal to provide a barrier to dissolution and corrosion. The principal problem with that approach is that, when the ammunition projectile is fired, the acts of firing, barrel abrasion, collision with other projectiles, and impact with the target or ground cause breaches in the coating. Such breaches remove the integrity of the coating and provide a route for the lead to solubilize and pollute. Thus, such barriers impart no environmental advantage.

In addition to lead, other metals, their alloys and their composites have been used as ballistic projectiles, including antimony, bismuth, chromium, cobalt, copper, depleted uranium (DU), tantalum, tin, tungsten, and nickel. Also, certain heavy metals and their alloys in the form of fibers, strips, and/or flakes are used in ballistic shells as chaff rounds or ‘radar flares’ to obscure potential missile targets or to deflect incoming missiles. Thus, the term “projectile” can be more fully described as a body in any physical form, including bullet, shot, pellet, slug, shell, missile, fiber, and foil, which is propelled at force by an explosive device, or indeed, any other form of physical or mechanical propulsion.

Like lead projectiles, most other metal projectiles and/or their corrosion products are potentially harmful to people and the environment:

    • Copper and its salts are frequently regarded as toxic, and certain compounds are SARA 313 Register materials.
    • Bismuth has been associated with Alzheimer's-like dementia.
    • Depleted uranium (DU) is at least as toxic as lead, and recently has been shown to exhibit mutagenic and genotoxic properties.
    • Pure tin is usually deemed innocuous to humans. However, it is toxic to microorganisms in the environment. Ballistic tin is usually used as an alloy with other metals such as antimony or bismuth owing to its potential transform from grey to white tin on firing. This phenomenon of pure tin could risk barrel blocking. Tin in its ballistic alloys can undergo redox corrosion to liberate bismuth and antimony compounds.
    • Tungsten-nickel-iron alloys and composites, frequently referred to as “heavy steel” or “heavy metal tungsten alloy” (HMTA), can corrode under oxygenating conditions to liberate oxides and salts. Additionally, in recent studies HMTA has been shown to exhibit genotoxic and mutagenic properties. Despite its low solubility, even tungsten carbide has been shown to be bio-available. Tungsten is a known ‘reproductive affecter’, and tungsten-nylon composite residues have been shown to be soluble under certain groundwater conditions, increasing its potential bioavailability. Furthermore, tungsten has been shown to be eco-toxic.
    • Fine nickel and certain of its compounds are known carcinogens. Such materials can be liberated by the corrosion of low-cost mild steel and soft iron shot.
    • Antimony is a known toxic and regulated material.

There is a compelling need for environmentally self-remediating ammunition and projectiles, whether made of lead or other materials.

SUMMARY OF THE INVENTION

According to the invention, a self-remediating projectile is provided. In one aspect of the invention, a conventional metal bullet, shot, slug, shell, pellet, fiber, foil, missile, etc. is coated or otherwise treated, in whole or in part, with a remediation agent, preferably in a binder, i.e., a polymeric matrix. The binder is typically water-soluble and/or biodegradable. The remediation agent (sometimes called an environmental remediation agent) comprises one or more materials capable of reducing or preventing the water-solubility of the projectile metal(s), or containing it within the vicinity where it lands when fired, thereby preventing or diminishing the leaching of the metal(s) into the environment. A partial list of remediation agents includes calcium and magnesium sulfides, oxides, and phosphates. Through careful selection of the remediation agent(s), the invention offers the benefit of rendering all of the metals in a projectile—not just lead—self-remediating.

A method of making a self-remediating projectile is also provided and comprises coating or otherwise treating a metal projectile with an organic solvent solution (or other mixture) of a binder polymer and a remediation agent; and drying the coated article. A technique such as tumble rolling can be utilized. In one embodiment, the projectile is coated or treated with an excess of remediation agent, thereby providing the advantage of potentially “shooting clean” a contaminated area through repeated firing of self-remediating projectiles into the contaminated area.

In another aspect of the invention, a self-remediating target, such as a clay pigeon, is provided and comprises a remediation agent coated on or otherwise applied to all or part of the target. The resulting targets can then be used to clean up a contaminated area, such as a shooting range, by “shooting clean” the area.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become better understood when considered in conjunction with the following detailed description and accompanying drawings, wherein:

FIG. 1 is a graph showing the corrosion of a 2 mm shot of 99.999% pure lead immersed in water for 100 days.

FIG. 2 is a graph showing the corrosion of a U.S. No. 8 lead-2% antimony shot immersed in water for 100 days. (Note: although the shot was sold as nominally containing 2% antimony, it actually assayed at 1.25% antimony (w/w).)

FIG. 3 is a schematic, partially cross-sectional view of a self-remediating, copper-jacketed, lead-antimony alloy bullet according to one embodiment of the invention, and

FIG. 4 is a graph showing the corrosion of a post-firing, self-remediating, No. 8 lead-2% antimony shot according to one embodiment of the invention immersed in water for 100 days. (See the note above in the description of FIG. 2.)

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, a self-remediating projectile is provided. In one embodiment, a time-release coating containing a remediation agent is applied to a round of ammunition or other projectile, effectively rendering the coated article environmentally self-remediating. The principles of Integrated Fixation Systems (“IFS”) detailed in U.S. patent application Ser. Nos. 09/072,771 and 09/646,544 (the entire contents of both applications being incorporated by reference herein) are applied to lead or other metal ammunition or projectiles such that they are pre-treated in advance of being disposed of, thus avoiding the inconvenience of regularly de-leading ranges and other locales, and thereby avoiding or reducing substantial site remediation costs. Minimal reagent is required, and there is thus no need to treat areas of the site on which the spent projectile does not fall.

A self-remediating projectile according to the invention has a reduced tendency to leach metal(s) into the environment, as a consequence of the metal(s) being passivated or rendered less water soluble than normal. Even post-firing, the projectile is protected by a passivating coating formed thereon. The invention is designed to work with any metal projectile, be it a bullet, shot, slug, shell, pellet, fiber, foil (e.g., chaff), or even a missile. The projectile may be a pure metal, a metal containing one or more impurities, an alloy, a metal-metal or metal-non-metal composite, or any other metal-containing or metallic substance. The projectile may be made of a combination of metallic substances. A nonlimiting list of metallic elements used in the manufacture of ammunition and other projectiles includes lead, antimony, bismuth, chromium, cobalt, copper, nickel, tin, tungsten, tantalum, and uranium. Iron (typically in the form of a steel jacket), is another example.

In one embodiment, a surface coating (sometimes referred to as an “integrated fixation system” or “IFS” coating) comprises a remediation agent carried in a binder, i.e., a polymeric matrix. The coating is conveniently prepared by dissolving a polymer in an organic solvent, adding a remediation agent, coating a projectile, and drying the projectile. In some embodiments, the surface of the metal projectile is physically or chemically scored, etched, or otherwise treated prior to being coated with an integrated fixation system, to improve the bond between the coating and the metal. The resulting self-remediating projectile can thus be characterized as a metal projectile having an integrated fixation system coated thereon, wherein the metal projectile has a surface adapted to facilitate strong adherence between the integrated fixation system and the metal projectile.

Nonlimiting examples of binder polymers include acrylic acid copolymers; copolymers of esters (e.g., vinyl acetate), amides (e.g., acrylamide), and/or vinyl alcohols; polyethylene glycols and glycol copolymers; hydratable cellulose compounds; and carboxylated copolymers of such materials. More generally, the binder polymer is any coatable, water-soluble or biodegradable polymer capable of adhering to lead or other heavy metal and releasing a remediation agent upon dissolution or degradation in water. Preferred polymers are pH-neutral, linear, and non-toxic (LD50 in mammals less than 5,000 mg/Kg). A variety of acrylic copolymers are available from suppliers such as Ciba-Geigy, Harco (UK), and Yule-Catto (UK).

A preferred binder polymer comprises a cation-capped copolymer of acrylic acid and an acrylic ester. For example, a copolymer of acrylic acid and methyl acrylate is prepared and then allowed to react with a hydroxyalkylamine, e.g., triethanolamine (“tris”). One such polymer comprises poly[(methyl acrylate)x(tris-capped acrylic acid)y], with the mole ratio of x:y being approximately 87:13. If excess tris is used, it has a plasticizing effect and helps condition the surface of a lead projectile to be coated; that is, it facilitates partial hydrolysis (corrosion) of the surface. From this it can be seen that copolymers capable of hydrogen bonding (e.g., carboxylated and/or hydroxylated polymers) should bind well to a metal surface.

Another copolymer for use as a binder polymer comprises poly(vinyl acetate)x(tris-capped acrylic acid)y, where x:y is approximately:94:6.

In each of the above two cases, the number of monomer repeat units (sum of x+y) in the copolymers will typically range from approximately 250 to 1500.

In one embodiment, the binder polymer, when applied to a metal bullet or other projectile, forms a matrix that is rendered at least as flexible as the heavy metal to which it is applied, and facilitates environmentally self-remediation of the underlying metal bullet or other projectile. This flexibility is induced by, e.g., internal plasticization by pendant moieties on the polymer or by the external addition of plasticizers to the matrix. A nonlimiting list of plasticizers includes alcohols, amines, ethers, esters and co-compounds thereof.

The binder polymer is dissolved in an organic solvent, preferably one having low or substantially no toxicity to mammals. Nonlimiting examples of solvents include esters, alcohols, and ethers (e.g., solvents used in paints and inks). Specific examples include ethyl acetate and propanol (e.g., propan-2-ol). Ideally, the solvent (or mixture of solvents) facilitates good film formation upon drying, and minimizes tack of the coated article. Optionally, additives such as methoxy, ethoxy, and/or hydroxy adducts of ethane, propane, and butane (e.g.) and other conventional anti-blocking aids are added to lower the resulting tack of the coated article.

The polymer solution is combined with one or more environmental remediation agent, i.e., an agent (plural or singular) capable of reducing the solubility of toxic metal ions and/or acting on potentially water-soluble heavy metals to prevent them from becoming soluble. Preferably, the remediation agent is capable of reducing the water-solubility of a heavy metal below the maximum amount permitted by statute, e.g., the U.S.-U.T.S. (Universal Treatment Standards) limits.

Nonlimiting examples of remediation agents include one or more of calcium (or magnesium) sulfide, phosphate, hydroxide, carbonate, oxide, or apatite;, di-calcium hydrogen phosphate; calcium di-hydrogen phosphate; triple super phosphate; dolomite; phosphoric acid; and/or mixed calcium-magnesium adducts of the aforementioned agents. “Triple super phosphate” (TSP) is Ca(H2PO4)2H2O (CAS No. 65996-95-4). Ideally, the remediation agent(s) is selected to work with all of the metals in a given projectile. Thus, while phosphates used alone can remediate lead, they do not work with common lead additives such as arsenic or antimony. Phosphates in combination with calcium sulfide and calcium carbonate and/or calcium oxide and/or calcium hydroxide (hydrated lime) however, should be capable of remediating virtually all metals of Group III and higher, including depleted uranium.

Preferred remediation agents are the Molecular Bonding System (MBS™) brand of remediation agents available from Solucorp Industries (West Nyack, N.Y.) For example, MBS 3.1™ is a 3:2:1 wt.-to-wt. (w/w) powder mixture of technical grade calcium sulfide, calcium carbonate, and triple super phosphate. MBS 20.1™ has the advantage of not adversely affecting the density of a coated metal projectile.

The amount of remediation agent(s) that is used will depend on the size, mass, and type of projectile that is being treated, and in some embodiments, on the environment in which the projectile is likely to be used, with the aim being to passivate and/or lower the water-solubility of the projectile metal(s). In some embodiments, an excess of remediation agent(s) is used. The resulting treated projectile can then be used to “shoot clean” a contaminated area, such as a shooting range. Heavy metals pollution already present in the area can be treated through the repeated firing of environmentally remediating ammunition into the area. Thus, the invention also provides a method of remediating an area contaminated with spent ammunition, comprising shooting clean the area with self-remediating ammunition, preferably self-remediating ammunition containing an excess of one or more remediation agents.

In one embodiment of the invention, an environmentally self-remediating bullet or other metal projectile is made by coating the metal article with an organic solvent solution (or other mixture) of a binder polymer and a remediation agent, followed by drying the coated article to drive off the solvent. A nonlimiting example of a suitable coating technique is “tumble rolling.” The article to be coated (e.g., a lead slug or shot) is rolled in the binder-remediation agent solution until evenly coated, and the solvent is then evaporated or otherwise driven off, (taking care to minimize any fire hazard). Optionally, the evaporated solvent is burned or, more preferably, condensed and reused. Optionally, precautions are taken against formation of excess static charge. Optionally, the article can be “over-rolled” when dry to give it a fine, smooth, glossy, black finish. (This is particularly suitable for shot or other ammunition where it is desirable to maintain an appearance familiar to the end user, but unnecessary where the slug will later be copper-jacketed or otherwise hidden from view.)

FIG. 3 shows a nonlimiting example of a copper-jacketed lead-antimony alloy bullet prepared in accordance with to the invention. The projectile (10) includes a lead alloy core (12) coated with an IFS coating (14). A steel piercing tip (16) sits atop the slug. Although not shown, the piercing tip, like the slug, can be coated with an IFS coating. The slug-tip combination is sheathed in a copper jacket (18).

Swaging and other methods for making ammunition are well known. A lead alloy (e.g.) is extruded as a wire, which is then snipped into cylindrical sections or cores. These cores can be coned at one end by insertion in a press (as in the case, e.g., of a 7.62 mm round). A small copper cup (pre-formed) is pressed in a series of operations into a copper bullet jacket. The core is inserted into the open back end, and the rim of the copper jacket is swaged over to seal the lead core into the jacket. The bullet is then re-pressed to give it the exact size needed to fit into the barrel A self-remediating round of ammunition is conveniently prepared by making a slightly undersized metal core, coating it with an IFS coating, swaging a copper jacket about the core (and optionally a piercing tip). In the case of lead, which has a density of 11.3, it is convenient to make a 5% undersized lead core and coat it with 1% by weight of an IFS coating (which has a density of circa 2 g/cc). The coated core is swaged in exactly the same manner as an uncoated core, and yields a jacketed slug that weighs about 2-3% less than an uncoated slug, i.e., the weight discrepancy is within normal production variance. In a 5.56 mm M-16 round, there is a steel piercing tip added to the copper jacket before the core.

The invention has the advantage of not being limited by the size of the projectile. It can be applied to all calibers of rounds, including calibers of 9 mm and above, whereas similar large caliber rounds made with purportedly non-toxic alternatives such as tungsten-nylon matrix can become physically unstable and frangible, rendering them liable to disintegrate on firing, with potentially dangerous consequences. Additionally the invention does not affect the long-term physically integrity of the projectile through adverse chemical interactions. In contrast, other non-toxic metal alternatives may become frangible and physically unstable on storage, through action of (1) adverse redox reactions between incompatible metal components, as may occur with copper-iron and tungsten-steel composites, and/or (2) degradation through thermo-chemical oxidative decomposition (sometimes known as plastic cancer) of their polymer composites, which can be accelerated by the proximity of the polymers to certain finely dispersed metals, e.g., as can occur with tungsten-polymer composites.

The invention does not require the coating to fully envelop the metal core. The enclosure of the spent projectile is achieved post-firing through hydration of the coating and release of the remediating reagent, which renders non-hazardous solubilized lead and creates a stable corrosion product over the surface of the potentially polluting item.

In another embodiment of the invention, the metal item is pre-treated or co-treated with a surface conditioning agent during application of the polymer so as to facilitate the partial passivation (corrosion) of the metal surface, and thereby facilitate a strong adhesion between the polymer matrix and the metal surface. A nonlimiting list of agents includes amines and their co-compounds, e.g., triethanolamine, triethylamine, related organic triamines, diamines, alkyl or aryl amines, and salts of the aforementioned compounds.

The following is a nonlimiting example of the invention.

EXAMPLE 1

A surface coating is prepared by forming a solution of (a) a linear copolymer polymer comprising poly[(methyl acrylate)x(tris-capped acrylic acid)y], where x:y is approximately 87:13 (100 parts by weight (pbw)), (b) ethyl acetate (100 pbw) and (c) propan-2-ol (100 pbw). This coating imparts moisture resistance to a coated metal article but, on immersion in water for more than a few hours, readily hydrates, crumbles and dissolves over a period of several days to weeks. Being a soluble acrylic polymer, it is intrinsically biodegradable.

The polymer solution is combined with a remediation agent known as Molecular Bonding System 3.1™ from Solucorp Industries: a 3:2:1 wt.-to-wt. mixture of technical grade calcium sulfide, calcium carbonate, and triple super phosphate) (200 pbw) and additional ethyl acetate (300 pbw) to form the IFS coating.

The IFS coating is applied to a US No. 8 lead—1.25% antimony alloy shot at a concentration of 1% by weight (dry weight) by a tumble rolling technique, followed by evaporation of the solvents.

The invention permits lead bullet slugs e.g., 5.56 mm or 7.62 mm or larger caliber slug cores, to be similarly coated, jacketed, and/or further processed without significant deviation from existing swaged bullet manufacturing processes.

IFS-coated shot prepared according to Example 1 was loaded into 12 gauge cartridges and fired. The post-fired shot was recovered and displayed the scars of surface disruption due to barrel abrasion and impact between pellets in flight and on impact with the ballistic target. The coating had the quality of both adhesion to the metal, in that it was not easily removed by the abrasion of the shooting process, and flexibility in that it remained on the surface of the lead pellet, whatever shape it assumed. This quality should permit the coating to remain in intimate and firm contact with a lead slug or other projectile even during the conventional swaging process used in bullet manufacture. Upon visual examination, the coating on the recovered shot was judged to have been disrupted in about 5% of its surface area.

The ballistic qualities of the shot were evaluated at 25 yards and 40 yards, and the spread was found to be not substantively different from that of uncoated shot pellets under the same conditions, there being only a 3.5% reduction in the density of the shot imparted by the applications of the IFS coating.

The post-fired shot was immersed in water at a rate of 10 parts shot to 100 parts water, and the coating noticeably degraded over several days, releasing the active remediating agent. The shot was rendered black, with a stable corrosion product that covered the whole surface of the lead shot, including the once potentially soluble exposed lead surfaces. Soluble lead was monitored over time, and leaching was observed to be at or below normal levels of detection (0.010 mg/Litre at 90% certainty) even after 100 days leaching (FIG. 4). The Comparable US-UTS limit for lead is 0.75 mg/Litre after 1 day leaching. Importantly, the leaching had been stemmed by a stable, corrosion-resistant coating that had been formed after the firing process.

Comparative leaching results are summarized in Table 1. Expected lead shot corrosion rates of circa 10,000 years in temperate regions and >1,000 years in tropical regions have been cited in the literature. (See “Contamination at Shooting Ranges,” Dr. Corrine Rooney, Soil Plant and Ecological Sciences Division Lincoln University, Canterbury, New Zealand http://www.lead.org.au/fs/shootingranges.pdf.) Our studies suggest that, given a surfeit of rain, pure lead shot might last 21,000 years, but commercial lead-1.25% antimony alloy shot would survive only 1,200 year. By contrast, the corrosion rate of the IFS-protected shot implied a corrosion time of circa 1.49 million years, indicating substantial environmental utility to IFS-treated shot.

TABLE 1
Comparative Corrosion Rates for US No. 8 Shot
Based on Lead Leaching
LinearRelativeImplied
SlopeCorrosionCorrosion
Samplemg/Litre/dayRateYears
Pure0.01290.05721,238
Lead
Lead-Antimony0.2281.001,179
Shot
Lead-Antimony0.000180.0011,493,455
Shot + 1% IFS

Although not bound by theory, it is believed that, upon release from the polymeric matrix, the remediation agent forms a cement-like structure that sheathes the metal slug or other metal article, in effect forming a “calcolith.” The invention is intended to reduce the solubility of metals commonly used in ammunition and other projectiles, and, advantageously, to passivate corroding surfaces of such metals, their alloys and composite alloys. The integrated fixation system described herein should, therefore, be of tremendous value in remediating these environmentally harmful ammunition materials, including tungsten-nickel steels commonly used as piercing tips in military 5.56 mm ammunition.

Materials chosen for the IFS polymer matrix and the remediation reagent, are preferably selected from a group of materials that are known to be—or from their known chemistry are reasonably anticipated to be—of low toxicity, and as a consequence they are not likely to cause long term toxicity to a wounded person and/or animal, should accidental or incidental wounding occur by the use or abuse of an IFS projected projectile. This should be of tremendous benefit to individuals unfortunate enough to be inflicted with a gunshot wound. It is common surgical practice in treating gunshot wounds that, if the slug is still in-situ, it is not removed unless it is easily accessible by the surgeon. The justification for this practice is that poking around for the bullet in a trauma victim can do more harm than good. Thus, wounded individuals have been known to carry lead slugs within them for prolonged periods (in the case of one WWI casualty, as long as 80 years). Although the wound itself is by far the greater problem, the long-term toxicity posed by the slug or shrapnel should be diminished greatly through use of this invention.

The invention has been described with reference to various embodiments, figures, and examples, but is not limited thereto. For example, just as a projectile can be coated with an excess of remediation agent and used to “shoot clean” a contaminated area, a remediation agent can be coated on or otherwise applied to a projectile used as a target, such as a clay pigeon, which can similarly be used to remediate a contaminated area by shooting it clean. For trap shooting and similar pastimes, target weight regulations may limit the amount of reagent that can be applied to the sporting clay or other target. The following example illustrates this aspect of the invention.

EXAMPLE 2

A surface coating is prepared by forming a dispersion of MBS 2.1™ (Solucorp Industries Ltd.) in polyvinyl acetate-polyvinyl alcohol, (PVAcx-PVAy, where the mole ratio x is >=65%). Specifically, a blend of 20% w/w/ PVAc-PVA solution, MBS 2.1™, and ethyl acetate solvent are mixed together at the ratio 1:2:1 pbw. 10 gram of the resulting dispersion is applied to the underside of a normal commercial or biodegradable clay pigeon, such as those supplied by CCI International Ltd (of Priors Haw Road, Corby, Northants, UK). On drying, the weight of the standard sized clay pigeon should be within the weight range 100-110 grams and will carry 4-5 grams of an IFS reagent, which may be liberated by biodegradation and or weathering to release sufficient reagent to remediate approximately 2.0 to 2.5 grams of soluble lead or passivate the surface against corrosion of a much larger proportion metallic lead shot. The above dispersion may be modified into a sprayable paint or re-formulated into an aqueous sprayable paint to facility mass manufacture.

From the preceding discussion and example, it can be seen that the invention also provides an environmentally remediating target comprising a clay sporting pigeon coated or otherwise treated with at least one environmental remediation agent. Preferably, the at least one environmental remediation agent is contained in a polymer binder. The invention also provides a method of remediating an area contaminated with spent ammunition, comprising shooting clean the area using self-remediating ammunition and clay sporting pigeons treated with at least one environmental remediation agent.

Persons having skill in the art to which the invention pertains will appreciate that the invention can be further modified without departure from the principles described herein, and without leaving the full scope of the invention, which is only limited by the appended claims.