JP2007519888A - Ammunition traps and heavy metal restoration in shooting ranges - Google Patents

Abstract

  The present invention provides a method for repairing lead and other heavy metals in ammunition traps and shooting ranges. One or more repair agents are added to the ammunition trap or shooting range. The repair agent reacts with the heavy metal to “fix” (or deactivate) the heavy metal, making them substantially non-leachable. The present invention also provides an improved ammunition trap.

Description

  The present application relates to heavy metal repair, and in particular to methods for repairing heavy metal ammunition, debris, particulates, dust and the like found in ammunition traps and at shooting ranges.

  Lead-antimony alloys and other heavy metals and their alloys are widely used in ballistic applications such as bullets and shots. Lead alloys are used worldwide in the range of 200,000 to 300,000 tons, of which about half are used in the United States. There are 9,600 shooting ranges in the United States, and about 70% of the ballistic metal is fired at the shooting range.

  When bullets are fired at the firing range, they cause significant contamination at concentrated locations through dissolution and corrosion of lead-antimony alloys under normal conditions. As shown in FIG. 1, pure lead in soft water produces a level of soluble lead concentration of 0.75 mg / liter or more at pH 7.5 in days to weeks. Lead-antimony alloys dissolve at a faster rate and result in higher levels of soluble lead as a result of the redox reaction that occurs between the lead and antimony metal present in the alloy (FIG. 2).

  Other heavy metals used in ballistic applications that may be present in the shooting range include antimony, copper, tungsten, tin, bismuth, silver, nickel, and zinc. All of these metals or their compounds can have adverse effects on human health or the environment.

  To minimize heavy metal contamination, a well-managed shooting range has an ammunition trap (or “bullet trap”) behind the target area. Bullets, shots, and other bullets, and their debris that are fired through the target and impinge on the bullet stop area or “trap”, remain in the ammunition trap (or “bullet trap”). These traps must be periodically repaired, and spent bullet fragments are removed for recycling.

  There are various designs for bullet traps. They include plates and pits, escalators, venetian blinds, rubber lamellae, granular rubber, and circulating water (snail traps). In general, most bullet traps fall into two types.

  Type A: Box or similar shaped device containing materials that absorb the mechanical impact of bullets, such as sand, rubber, hydrogel blocks, rubber or polyurethane curtains, and similar materials.

  Type B: A large steel plate for directing bullets to a mobile liquid energy dissipation system. Such systems typically utilize flowing water, oil, or similar liquids to minimize scratch and impact damage within the trap.

  A trap that combines the above two types may be used. That is, the trap collects ammunition shock absorption and / or deflection means (eg, impact plates, deflection chambers, sandboxes, moving fluids, rubber pieces, or curtains) and bullet fragments, particulates, and / or dust. Of containers may be included.

  These prior art bullet traps minimize the generation of dust, but when exposed to the surrounding environment, soluble lead salts that can flow into the drainage system near the shooting range due to corrosion, etc. due to corrosion. Generates particulates and other debris that can be produced. Also, the liquids used in Type B traps can produce water containing heavy metals caused by lead dust and particulate corrosion in the circulating lubrication system. Thus, there is a need for improved environmentally self-healing ammunition traps and methods for making existing traps self-healing.

  The present invention addresses the problems posed by heavy metal based ammunition in ammunition traps and shooting ranges, including spent ammunition, ammunition debris, particulates, and dust contamination. According to a first aspect of the invention, there is provided a method for repairing heavy metal in an ammunition trap comprising adding at least one heavy metal repair agent to the ammunition trap. As used herein, the term “heavy metal repair agent” (or simply “repair agent”) alone or in combination with one or more additional substances converts heavy metals into a water-insoluble form. Or by making the heavy metal substantially non-leachable (ie by encapsulating the metal in a substantially non-leachable matrix) having the ability to “fix” the heavy metal. As preferred, the restoratives have the ability to bring the water solubility of heavy metals below the maximum allowed by law, such as US U.S.S. limits. In the case of lead-based ammunition, the preferred repair agents are compounds of calcium sulfide, calcium carbonate, and calcium phosphate (or lime heavy superphosphate). In one embodiment, one or more repair agents are added to the ammunition trap in blocks (or chunks) or pellets, debris, free flowing powder, slurry, or other suitable form. In the presence of water, the repair agent reacts with heavy metal from spent ammunition, bullet debris, particulates, and / or dust to repair (or remediate) the heavy metal in the trap.

  According to a second aspect of the present invention, a heavy metal repair block (or mass) or repair pellet for use in bullet traps and / or shooting ranges and a method for manufacturing the same are provided. In one embodiment, the repair block (or mass) or repair pellet includes at least one repair agent that is dispersed or included in a water-soluble or water-degradable binder or matrix. Optionally, the block or pellet further comprises one or more surfactants, dispersion aids, and / or flocculants to assist in the deposition of the precipitated insoluble metal compound. Such a block may, for example, form a mixture of at least one restorative agent and a water-soluble or water-degradable binder; generate a melt by heating the mixture; and pellets or It can be formed by forming a block. The repair block may, to some extent, be formed based on the principles of the Integrated Fixation Systems technique described by Webster and Hurley in US Pat. No. 6,838,504.

  In accordance with a third aspect of the present invention, one or more repair agents are introduced into the range drainage system or, particularly in the case of outdoor shooting ranges, the one or more repair agents are A method is provided for repairing (or remediation) a shooting range contaminated with at least one heavy metal, including allowing contact with (i.e., ground). By adding one or more restorative agents to a pump, pond, drainage channel, etc. in the shooting range, or simply to the ground itself, the restoratives react with heavy metal from spent ammunition, ammunition fragments, particulates, or dust. And thereby prevent soluble lead, antimony, and other heavy metals from flowing into public waterways and the like.

  According to a fourth aspect of the present invention, there is provided an improved ammunition trap comprising at least one heavy metal repair agent in combination with an ammunition trap. In one embodiment, the improved ammunition trap comprises at least one ammunition shock absorption and / or deflection means; a container for used ammunition, ammunition debris, particulates, or dust; and at least one in said container Provide a repair agent.

  Advantages and various features of the present invention will become more apparent from the following detailed description when taken in conjunction with the drawings.

According to one aspect of the invention, a method is provided for repairing one or more heavy metals in an ammunition trap. In one embodiment, the method of the present invention includes adding at least one repair agent to the ammunition trap. Examples of (but not limited to) restoration agents are calcium sulfide, calcium phosphate, calcium hydroxide, calcium oxide, calcium carbonate, magnesium sulfide, magnesium phosphate, magnesium hydroxide, magnesium oxide, magnesium carbonate, apatite, dicalcium hydrogen phosphate, phosphoric acid Calcium dihydrogen, lime heavy perphosphate, dolomite, phosphoric acid, and / or mixed calcium addition products of these compounds. Other examples of restoratives are: phosphoric acid and its salts that can be used for lead reduction; functional but slow mineral apatite (Ca ₅ (PO ₄ ) ₃ (F, Cl, OH )); Via adsorption, acts as a result of their high alkalinity (thus their effects may not be permanent); alkaline earth silicates (eg calcium silicate); silicic acid and alumina hydrates: And metal-absorbing clays such as bentonite and frath earth. When they are used, phosphates are considered suitable for lead repair, but they will not repair other metals.

Environmental repair agents are available from Solucorp Industries as Molecular Bonding System® or MBS® and from Metals Treatment Technologies as Ecobond®. Preferred restoratives include a mixture of technical grade calcium sulfide, calcium phosphate or heavy superphosphate, and calcium carbonate available from Solucorp Industries. “Heavy superphosphate” (or TSP) is Ca (H ₂ PO ₄ ) ₂ —H ₂ O (CAS No. 65996-95-4). A particularly preferred restorative for lead and lead-antimony alloys is MBS® 2.1 (a 3: 2: 1 (wt / wt) mixture of calcium carbonate, calcium sulfide, and lime heavy superphosphate). MBS® 2.1 is not pH dependent and can repair (or remediate) lead under conditions ranging from pH 1 to pH 13. In contrast, phosphate and silicic acid are pH dependent. Phosphate is functional under roughly neutral (pH 6-8), silicate is strongly alkaline (> pH 10) and functional, and MBS® restorative is soluble lead When salt is administered orally, it is converted to non-toxic lead sulfide.

  The restorative agent is added to the ammunition trap in blocks (or chunks) or pellets, debris, free flowing powder, slurry (eg, an aqueous slurry of one or more restorative agents), or other suitable form. Repair blocks are particularly preferred, allowing the repair agent contained therein to be released in a sustained release manner with a minimal increase in system alkalinity. When applied at a rate that is too fast, it not only wastes the repair agent, but also causes a temporary increase in dissolution of fine lead metal debris in the trap sludge (or precipitate), It takes a long time to become fully effective.

  The amount of repair agent added to the trap depends on the type of trap, the type and amount of heavy metal contamination, the type of repair agent used, and other factors apparent to those skilled in the art. Ammunition traps that are used significantly during any period of time will typically require a greater amount of repair agent than less used traps.

  Regardless of whether used in blocks, pellets, debris, powder, slurry, or other forms, restorations are most likely to be exposed to used ammunition trap ammunition debris, particulates, or dust Added to. Such areas include, for example, the pits of plates and pits; drains for circulating fluid traps, waterways, or liquid tanks; containers near deceleration chambers or shock absorbing plates; or traps that are likely to be exposed to heavy metals. Is the other part.

  For example, in one embodiment, one or more reagent blocks may be placed in a Type A ammunition trap (as described above) where the debris is likely to occur. Contact with moisture that causes the start of corrosion of the lead debris collected by the trap activates the blocks, releasing their repairing agent and removing used lead debris in the trap during its effective use. Causes continuous repair. The block may be replaced during regular repairs of the trap. Additionally, the repair block may be incorporated into a rubbery hydrogel or other material that constitutes the bullet trap energy absorbing material.

  In another embodiment, one or more repair blocks may be applied directly to a Type B trap (described above). The applied repair block will be dispersed in the liquid system to repair lead debris and corrosion products. Spent lead removed for recycling has a blackish color with passivated corrosion products and is stabilized against further oxidation and corrosion, but they are not treated as such lead Recyclable in a similar manner. The addition of a repair block to the liquid lubricant eliminates soluble lead from the lubricant, reduces the risk of liquid waste, and consequently reduces the cost of waste disposal.

  In a second aspect of the present invention, a heavy metal repair block or pellet and a method for manufacturing such a block or pellet are provided. In one embodiment, the heavy metal repair block or pellet includes at least one repair agent that is dispersed or included in a water-soluble or water-degradable binder or matrix. The composition is appropriately sized and shaped (small or medium block, pellet, etc.) to function within one or more regions of the trap. Upon contact with water, the binder dissolves or decomposes over a specified period of time, reacts with lead, antimony, and other heavy metals in the trap, immobilizing (or inactivating) them.

  Examples of (but not limited to) binders are hydrated and / or degradable polyethylene glycol and ethylene glycol copolymers; polyacrylates and / or hydratable cellulose compounds, and / or their methyl, Includes water soluble and / or water degradable waxes such as ethyl, propyl, and / or butyl ether. A mixture of these binders may also be used.

Optionally, the repair block or pellet may further comprise one or more surfactants, dispersion aids, and / or flocculants. Examples of surfactants and dispersants that can be used (but not limited to) are polyethoxyethylene ethers of fatty acids, polyethoxyethylene esters of fatty acids, and polyethoxyethers of alcohols (eg, the chemical formula CH ₃ (CH ₂ ) _x- O— (CH ₂ CH ₂ ) _y —OH, where x> = 5 and y> 1). Typical surfactant concentrations in the repair block are 0.1 to 1% by weight of the total block. Examples of (but not limited to) flocculants are A120, A130, and A150 available from Cytec Industries BV.

  Heavy metal repair blocks or pellets can be formed in a direct manner. In one embodiment, the method of the present invention comprises at least one repair agent and a water-soluble or water-degradable binder (and optionally one or more surfactants, dispersion aids, and / or flocculants. ); Generating a melt by heating the mixture; and forming pellets or blocks from the melt. For example, a block or pellet may be “cast” by pouring the monster to be tied into a mold and curing it. The pellets or blocks thus formed can be added to an ammunition trap to repair heavy metal ammunition debris, particulates, or dust.

  To increase the speed of the manufacturing process, the repair blocks and pellets may be formed by a variety of mass production processes such as, for example, prilling or compression into blocks or tablets; flaking. However, the present invention is not limited by the physical methods of manufacturing the blocks described herein.

  In another aspect of the present invention, heavy ammunition from the shooting range used ammunition, ammunition debris, particulates, or dust can be used to transfer one or more remedial agents to indoor or outdoor shooting ranges (drains, waterways, It is restored by introducing it into a drainage system (such as a pond and / or waterway) or simply into the ground of the outdoor shooting range itself. Restoratives react with heavy metals from used ammunition, ammunition fragments, particulates, or dust, thereby preventing soluble lead, antimony, and other heavy metals from flowing into public waterways and the like.

  According to a fourth aspect of the present invention, there is provided an improved ammunition trap comprising at least one heavy metal repair agent in combination with an ammunition trap. The ammunition trap is essentially “environmentally self-healing” because it restores lead and other heavy metals from the ammunition that enters the trap. In one embodiment, the improved trap comprises at least one ammunition shock absorbing and / or deflecting means; a container for used ammunition, ammunition debris, particulates, or dust; and at least one repair in said container Provide agent. In alternative embodiments, the ammunition trap may have an alternative configuration and / or the repair agent may be placed elsewhere within the trap.

  Referring to FIG. 3, an improved ammunition trap according to one embodiment of the present invention is illustrated. Trap 10 is of the circulating water type (also referred to as a “snail trap”) and includes a deflection chamber 12 configured to circulate water therethrough. A bullet or bullet fragment 14 enters the trap and travels along path 14a until it contacts the deflection chamber and the flow of circulating water. The bullet further loses its kinetic energy and travels along the chamber until it falls through the chamber gap 16 and is captured by the screen or grill 18 after dropping from the gap. Smaller bullet fragments, fine particles, and dust pass through the screen 18 together with water and are stored in the container 20. This container is also utilized as a reservoir for water used in the system. As time passes, sludge (or sediment) accumulates at the bottom of the reservoir. Water from the container is pumped through the return tube 24 and returned to the deflection chamber 12.

  In accordance with the present invention, the one or more restorative agents 30 may block, pellet, powder, slurry, or otherwise form a water reservoir / container 20, input tube (not shown), or other suitable location. To be introduced into the trap. When blocks or pellets of the kind described above are used, they have the advantage that the repair agent can be released into the system in a measured ratio, i.e. in a sustained release manner.

In the following, although not limiting, examples of the invention are described.
Example 1
Mix technical grade calcium sulfide, calcium phosphate, calcium carbonate, polyethylene glycol wax (molecular weight about 1,500) (2: 1: 3: 2 weight ratio), heat the mixture to 100 degrees, Heavy metal repair blocks composed of these components were produced by casting the melt into 5-100 gram blocks. About 1.3 cm square reagent blocks were dispersed in water for 24-48 hours.

Example 2
Mix technical grade calcium sulfide, calcium phosphate, calcium carbonate, calcium hydroxide, polyethylene glycol wax (molecular weight about 1,500) (weight ratio of 2: 1: 1: 2: 2) and mix the mixture to 100 A heavy metal repair block consisting of these components was produced by heating to a temperature and casting the melt into 5-100 gram blocks. About 1.3 cm square reagent blocks were dispersed in water for 7-14 days.

  The 5 g block produced in the above example will absorb over 1.8 grams of soluble lead when immersed in water. If excess reagent is used (relative to the amount of soluble lead present), the level of leachate is reduced below the UTS limit by the US TCLP test process.

  21 days immersion in water of a 5 g block produced according to Example 2 did not cause a discernable reduction in chemical efficacy. A 21-day immersion in fresh water with a block flow of the same size resulted in exposure to soluble lead and decreased efficacy by 10%. The length of dissolution and efficacy of the processing block may be controlled by the size and shape of the block.

Example 3
A heavy metal repair test was conducted on four circulating water bullet traps (also called “snail traps”) supplied by Savage Range Systems in an indoor shooting range. Thousands of bullets are fired at the shooting range annually. Four 2.4 meter wide traps were placed in a row immediately after the 9.1 meter wide target area. The trap sumps were interconnected to form a single sump below the four trap deceleration chambers. The bullets that have passed the target penetrate into the traps, are carried in the trap's circulating water system until they lose ballistic energy, and accumulate on the bullet capture screen under each trap. Due to the lead-antimony alloy and other friable bullet structures, a portion of each used slag (or blob) is carried by a circulating water system and then drainage or reservoir located directly under the trap Deposit as sludge (or sediment) in the container (equal to about 2.0 m ³ in this example). When combined, the four traps contain approximately 1062 liters of water containing 1% typical alcohol glycol based antifreeze. Prior to treatment, the water circulating in the trap (which is a composite of sludge and water) showed 173 mg / liter of soluble lead. The sludge showed 1,340 mg / liter soluble lead (by TCLP SW846 treatment).

  To each of the four traps, 9.1 kg of restorative (MBS 2.1 obtained from Solucorp Industries) equal to 3.44% throughput was added, and the traps were used for an effective shooting range for another 6 weeks. Maintained in a state. After treatment and repair, the soluble lead in the water circulating in the trap dropped to 7.68 mg / liter, and the sludge showed 2.87 mg / liter of soluble lead (by TCLP SW846 treatment).

  Although the present invention has been described with various embodiments and drawings, the present invention is not limited to these embodiments. It will be apparent to those skilled in the art that various modifications can be made to the invention as defined by the appended claims without departing from the spirit of the invention.

FIG. 5 is a graph showing corrosion of a 99.999% lead 2 mm shot immersed in water for 100 days. No. 8 lead in the US (usually sold as containing 2% antimony, but actual analysis shows it contains 1.25% antimony (W / W)) -A graph showing the corrosion of antimony shots. 1 is a schematic diagram of one embodiment of a self-healing ammunition trap according to the present invention. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bullet trap 12 Deflection chamber 14 Bullet 14a Bullet path 16 Chamber gap 18 Bullet capture screen 20 Water storage container / container 24 Water return pipe 30 Heavy metal restoration agent

Claims (21)

  A method for repairing heavy metal in an ammunition trap comprising: adding at least one heavy metal repair agent to the trap.   The at least one restorative agent is calcium sulfide, calcium phosphate, calcium hydroxide, calcium oxide, calcium carbonate, magnesium sulfide, magnesium phosphate, magnesium hydroxide, magnesium oxide, magnesium carbonate, apatite, dicalcium hydrogen phosphate, calcium dihydrogen phosphate , Heavy superphosphate, dolomite, phosphoric acid, mixed calcium addition products of these compounds, phosphoric acid and their salts, alkaline earth silicates, silicic acid, alumina hydrate, metal-absorbing clays, and mixtures thereof The method of claim 1, wherein the method is selected from the group consisting of:   The method of claim 1, wherein the at least one restorative agent comprises a mixture of calcium sulfide, calcium carbonate, and calcium phosphate or heavy superphosphate.   The method of claim 1, wherein the at least one restorative comprises a mixture of calcium carbonate, calcium sulfide, and heavy superphosphate in a ratio of 3: 2: 1 (wt / wt).   The method of claim 1, wherein the at least one restorative agent is added to the trap as blocks or pellets, debris, free flowing powder, or slurry.   A method for repairing heavy metal in an ammunition trap comprising: adding to the trap a block comprising at least one repair agent dispersed in a binder.   The at least one restorative agent is calcium sulfide, calcium phosphate, calcium hydroxide, calcium oxide, calcium carbonate, magnesium sulfide, magnesium phosphate, magnesium hydroxide, magnesium oxide, magnesium carbonate, apatite, dicalcium hydrogen phosphate, calcium dihydrogen phosphate , Heavy superphosphate, dolomite, phosphoric acid, mixed calcium addition products of these compounds, phosphoric acid and their salts, alkaline earth silicates, silicic acid, alumina hydrate, metal-absorbing clays, and mixtures thereof The method of claim 6, wherein the method is selected from the group consisting of:   7. The method of claim 6, wherein the at least one restorative agent comprises a mixture of calcium sulfide, calcium carbonate, and calcium phosphate or heavy superphosphate.   The method of claim 6, wherein the binder comprises a water soluble and / or water degradable wax.   10. The method of claim 9, wherein the water soluble and / or water degradable wax is selected from the group consisting of hydratable and / or degradable polyethylene glycols, copolymers of ethylene glycol, and mixtures thereof. .   7. The binder according to claim 6, wherein the binder is selected from the group consisting of polyacrylate hydratable cellulose compounds, hydratable cellulose compounds methyl, ethyl, propyl, and / or butyl ether, and mixtures thereof. the method of.   The method of claim 6, wherein the block further comprises one or more surfactants, dispersion aids, and / or flocculants. The block is a polyethoxyethylene ether of a fatty acid, a polyethoxyethylene ester of a fatty acid, and a polyethoxy ether of an alcohol (for example, the chemical formula CH ₃ (CH ₂ ) _x —O— (CH ₂ CH ₂ ) _y —OH (where 13. Process according to claim 12, wherein the process is selected from the group consisting of (polyether alcohols) where x> = 5 and y> 1). A method of making a heavy metal restoration agent block or pellet comprising at least one heavy metal restoration agent dispersed within the block or pellet comprising:
Forming a mixture of at least one restorative agent and a water-soluble or water-degradable binder;
Heating the mixture to form a melt; and
A manufacturing method comprising casting the melt into pellets or blocks.   The method of claim 14, wherein the mixture further comprises one or more surfactants, dispersion aids, and / or flocculants.   A heavy metal repair block or pellet comprising at least one heavy metal repair agent dispersed in a water-soluble or water-degradable binder and one or more surfactants, dispersion aids, and / or flocculants.   A method for repairing a shooting range contaminated with at least one heavy metal, the method comprising introducing one or more repair agents into the drainage system of the shooting range.   A method for repairing an outdoor shooting range contaminated with at least one heavy metal, comprising allowing one or more repair agents to contact the shooting range.   An improved ammunition trap comprising at least one heavy metal repair agent in combination with an ammunition trap.   An improved ammunition trap comprising at least one ammunition shock absorption and / or deflection means; a container for used ammunition, debris, particulates and / or dust; and at least one restorative agent in said container.   A bullet trap comprising a box and a shock absorbing material, the bullet trap including a heavy metal restoration agent in the box.

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