Abstract: A method of reducing or preventing the amount of iron sludge or precipitate that forms as a result of the recovery of silver from chemical solutions, such as a standard photographic solution. The method generally involves the introduction of a source of a conjugate organic base, such as a weak organic acid like citric acid or a salt of the conjugate organic base like a citrate salt, to the chemical fluid either before or during the silver recovery process. Preferably the source of conjugate organic base is introduced by combining it with a binder to form a time release cake or placing it in a container that has a semipermeable membrane that maintains the concentration of the conjugate organic base in the chemical fluid from about 0.2 to about 78 milimolar over a period of time.

Abstract: A method of removing contaminate material from a flowable material, comprising the following steps. A first container defining a first chamber is provided. A second container defining a second chamber is arranged within the first chamber. A first removal material is arranged within the second chamber. A second removal material is arranged within the first chamber. The flowable material is caused to flow along a removal path through the first removal material to remove a first portion of the contaminate material and through the second removal material to remove a second portion of the contaminate material.

Abstract: A removal system for removing a waste metal from a waste solution. The removal system comprises outer and inner containers, inlet, intermediate, and outlet conduits, and first and second reaction media. The inner container defines an upper wall portion and is located within the outer container. The inlet conduit allows fluid to flow to the inner chamber and extends through the upper wall portion of the inner container. The intermediate conduit allows fluid flow from the inner chamber to the outer chamber. The outlet conduit allows fluid flow out of the outer chamber. The first reaction media located in the inner container. The second reaction media located in the outer container. The waste solution is forced along a removal path through the inlet conduit, the first reaction media, the intermediate conduit, the second reaction media, and the outlet conduit.

Abstract: The present invention relates to the use of fine metal particles for the recovery of silver from a silver-bearing photographic waste solution. In particular, the metal particles are encapsulated in a hydrophilic colloid that allows for the permeability of water and silver ions. When contacted with the silver-bearing photographic waste solution, the hydrophilic colloid will imbibe water and swell. At the same time, the silver ions can permeate the colloid matrix and come into contact with the metal particles, preferably iron particles, at which point a metal—metal exchange reaction takes place.

Abstract: A removal system for removing a waste metal from a waste solution. The removal system comprises outer and inner containers and inlet, intermediate, and outlet conduits. The outer container defines an outer chamber, and the inner container defines an inner chamber. The inner container is located within the outer chamber. The inlet conduit allows fluid to flow from an exterior of the outer container to the inner chamber. The intermediate conduit allows fluid flow from the inner chamber to the outer chamber. The outlet conduit allows fluid flow from the outer chamber to the exterior of the outer chamber. A first reaction media located in the inner chamber, and a second reaction media located in the outer chamber. In use, the waste solution is forced along a removal path through the inlet conduit, the first reaction media, the intermediate conduit, the second reaction media, and the outlet conduit.

Abstract: The present invention relates to the use of fine metal particles for the recovery of silver from a silver-bearing photographic waste solution. In particular, the metal particles are encapsulated in a hydrophilic colloid that allows for the permeability of water and silver ions. When contacted with the silver-bearing photographic waste solution, the hydrophilic colloid will imbibe water and swell. At the same time, the silver ions can permeate the colloid matrix and come into contact with the metal particles, preferably iron particles, at which point a metal-metal exchange reaction takes place.

Abstract: A method for preparing ultra-pure silver from a crude silver halide matrix containing metallic and/or non-metallic impurities, said method comprising; roasting the crude silver halide matrix to substantially remove carbonaceous material; treating the roasted crude silver halide matrix with ammonium hydroxide to dissolve the silver halides and form an ammonium hydroxide reaction mixture; adding an initial reducing agent to the ammonium hydroxide reaction mixture to precipitate a crude silver powder mixture; separating the crude silver powder mixture from the ammonium hydroxide reaction mixture dissolving the crude silver powder mixture in nitric acid to form a crude silver nitrate solution; adding a first selective reducing agent to the crude silver nitrate solution to precipitate a silver/contaminant matrix and form a partially purified silver nitrate solution; separating the partially purified silver nitrate solution from the precipitated silver/contaminant matrix; adding a second selective reducing

Abstract: A method for preparing ultra-pure silver from a crude silver mixture containing metallic and/or non-metallic impurities, said method comprising; dissolving the crude silver mixture in nitric acid to form a crude silver nitrate solution; adding a first selective reducing agent to the crude silver nitrate solution to precipitate a silver/contaminant matrix and form a partially purified silver nitrate solution; separating the partially purified silver nitrate solution from the precipitated silver/contaminant matrix; adding a second selective reducing agent to the partially purified silver nitrate solution to precipitate silver powder; and isolating the silver powder.

Abstract: An organic-inorganic polymer comprising aluminosilicate having grafted thereon an organic radical having a —SH or —S(—CH2)n—S— group wherein n is from 0 to 4.

Abstract: Metal ions and/or complexes of metal ions are removed from a solution by formation of an insoluble chelated complex of the metal ions and a polymeric precipitating agent. A two-step process of mixing the influent with the precipitating agent is used to induce rapid precipitation and obtain large, self-agglomerated precipitate without addition of flocculating agent and/or pH adjustment. In addition, parallel loops are employed to simultaneously discharge treated metal-free solution and effectively collect/remove the precipitate-containing sludge without interfering with each other. The metal capturing capacity of the polymeric precipitant is maximized by forcing the influent solution through layers of the collected precipitate and by recycling unsaturated metal-precipitant complexes in the processing loop.

Abstract: There is provided a method for removing silver from photoprocessing solutions containing hardening agents which comprises:a) adding a chelating agent to the photoprocessing solution in an amount sufficient to inhibit the precipitation of the high valent cations of the hardening agents;b) adding a base to adjust the pH of the photoprocessing solution to a value above 5.5; andc) adding a chemical precipitant for the silver contained in the photoprocessing solution;and optionally adding as a final component a flocculating agent which causes the precipitate to grow in size.

Abstract: Value metal, for example, silver in a spent silver bearing photographic solution is efficiently recovered in an exchange mass comprising a particulate inert substrate, for example, cellulosic fibers, synthetic fibers or sponge particles, co-mingled and interlocking with elongate particles of replacement metal, for example, strands of steel wool; the substrate defines a non-channeling random flow paths for liquid flow, and inhibits carriage of recovered value metal by the flowing liquid.

Abstract: There is provided a process for converting a silver-mercapto-s-triazine precipitate to a solid containing silver and a solution containing mercapto-s-triazine by contacting the silver-mercapto-s-triazine precipitate with one or more reducing agents. In preferred embodiments, at least one of the reducing agents has a redox potential more negative than about -0.9 V vs. Normal Hydrogen Electrode, NHE.

Abstract: Spent solutions from photographic processors are fed into a conduit (18) to which subsequently are added precipitating agents from a first source (22) and flocculating agents from a second source (28); so that, well grown or ripened clumps of flocculated solids are formed along the conduit before being emptied into a gravity collecting vessel and shipping container (38) from which clarified liquids are displaced by a mass (50) of accumulated flocculated solids, typically through a filter (58, 142, 150, 158, 162, 166, 220)for removal of any unsettled fines. Many of the clumps of flocculated solids become enlarged enough to individually extend across and substantially fill a cross-sectional area of the conduit. As a result, the enlarged clumps substantially block passage of and strain from the solution remaining fine particles which then adhere to the clumps.

Abstract: A silver recovery device (30) is described for removing silver from a silver-containing solution. The device (30) comprises an ion-exchange resin bed (34) and a pump (62) for directing the solution through the resin bed (34). The pump (62) is positioned downstream of the resin bed (34) and the resin bed (34) is held within a retaining space (36) of variable dimensions. Higher liquid flow rates are thereby achievable, without fluidization of the resin.

Abstract: A process for recycling polyester contained in waste materials is provided. The polyester is converted into a corresponding acid salt of a polybasic organic acid and a polyol. The process steps generally include first combining materials containing polyester with an alkaline composition to form a mixture. The mixture is heated, causing the polyester to convert to the acid salt and polyol. The polyol is evaporated and separated from the acid salt.

Abstract: An agent for treating metal ions in an aqueous solution, comprising a solid porous carrier and, supported thereon, an organic reagent (hereinafter referred to as a "redox reagent") which is capable of converting metal ions (inclusive of metal complex ions) contained in an aqueous solution to zero valent metal or monovalent metal ions by a redox reaction and which is capable of carrying out oxidation-reduction reversibly.

Abstract: The present invention is a method for cleaning and preparing photographic manufacturing equipment surfaces. An aqueous solution of potassium iodide and ferric ethylenediamine tetraacetate is prepared. The solution is flushed over the surfaces of the photographic manufacturing equipment removing deposited silver halide and silver. A high purity water flush is then performed.

Abstract: An improved apparatus and method for recovering metallic silver from solutions containing silver ions by reducing silver ions and oxidizing an element in the electromotive series above silver, such as iron. The apparatus provides plug flow of solution into the reaction media and thereby eliminates the principal cause of channelling and premature failure of the media. A distribution chamber distributes solution uniformly to a porous pad of tangled threads or fibers ahead of the media. This ensures a planar flow front of solution as it enters and passes through the media. In a preferred embodiment, the pad is resilient and is supported by a highly open grating. By eliminating the flow and pressure imbalances or gradients at the entry to the media which are inherent in previous apparatus designs, the invention prevents or greatly retards the onset of channelling or plugging of the media.

Abstract: Photoemulsion is reduced with a combination of reducing sugar and sodium borohydride, resulting in increased silver recovery.

Abstract: A silver recovery element (10) for treating a photographic developer solution containing silver ions comprises a substrate (20) having thereon a hydrophilic colloid layer containing physical development nuclei. The invention also comprises a process for recovering silver from a photographic developer solution containing silver ions, such process comprising contacting the solution with the silver recovery element. The contacting is for a time sufficient to reduce the concentration of silver in the solution to a desired level. The recovery element and process for its use are useful in treating a seasoned photographic developer solution containing silver ions.

Abstract: An effluent precipitation and neutralization chamber for mixing and neutralizing spent photographic developer and fixer. The fixer inlet discharging into a vertically oriented conduit located within the vessel, which contains iron therein and defines a gravity flow path for flow of the fixer within the vessel from the inlet to the bottom of the vessel. A layer of steel wool is positioned on the bottom of the vessel in the flow path of the fixer. Baffles inside the chamber promote mixing of the developer and fixer. The desilvered fluid is diluted with wash water before it is discharged from the chamber. A wash water inlet tube is aligned with an open ended vessel that surrounds the discharge outlet to dilute the mixed and neutralized developer and fixer.

Abstract: A novel composition for use in reducing and recovering metals, such as silver, and for use in stripping adhesive polymer layers from various polymer bases, such as polyester, and processes for using same are provided. The composition and variations thereof can be useful in separating an adhesive polymeric layer from the film for recovery of either. The composition comprises a reducing sugar/alkaline solution that is particularly useful for recovering silver from polyester photographic film where a silver halide light-sensitive emulsion layer is adhered to the polyester film by a polymeric adhesive resin, such as resins containing copolymers of polyvinylidene chloride and polyvinyl chloride. Processes for separation and recovery are also disclosed and claimed.

Abstract: An effluent precipitation and neutralization chamber for mixing and neutralizing spent photographic developer and fixer. A baffle and long folded ribbons inside the chamber promote mixing of the developer and fixer. A source of iron ions such as fine steel wool is immersed in the fluids. Ion exchange between the steel wool and the photographic fixer recovers silver from the fixer. The desilvered fluid is diluted with wash water before it is discharged from the chamber. A wash water inlet tube is directly aligned with the discharge outlet opening in the chamber so that wash water can flow almost directly into the outlet tube to dilute the mixed and neutralized developer and fixer.

Abstract: An element and a process for recovering silver from a photographic developer solution containing silver ions. The silver recovery element (10) comprises a support (12) having a hydrophilic colloid layer (16) containing physical development nuclei on at least one of two opposing outer surfaces. Raised portions (20) space adjacent surfaces in the element's rolled-up configuration. The element can be contacted with the developer solution to recover silver from the solution.

Abstract: A process for treating a photographic developer solution containing silver ion comprises contacting the solution with a silver recovery element (10), which comprises a substrate (12) having thereon a hydrophilic colloid layer (16) containing physical development nickel. The contacting is carried out for a time sufficient to reduce the silver concentration in the developer solution to a desired level. The process is useful for treating a seasoned or unseasoned photographic developer solution containing silver ions.

Abstract: Aqueous iodine-iodide etching solutions are employed in the recovery of precious metals. Elemental iodine is precipitated from spent etching solutions and used to supply both the iodine and iodide of new etching solutions. Prior to extraction of the elemental iodine, used solutions, if not substantially contaminated, may be oxidized and recycled for further precious metal recovery. Aqueous etching solutions of hydriodic acid and iodine, or of ammonium iodide and iodine may be employed. Etching in such solutions, as well as in solutions of iodine and an alkali metal iodide, such as potassium iodide, may be accelerated by the use of small amounts of hydrogen peroxide (or equivalents) during etching.

Abstract: An effluent precipitation and neutralization chamber for mixing and neutralizing spent photographic developer and fixer. A baffle and long folded ribbons inside the chamber promote mixing of the developer and fixer. A source of iron ions such as fine steel wool is immersed in the fluids. Ion exchange between the steel wool and the photographic fixer recovers silver from the fixer. The desilvered fluid is diluted with wash water before it is discharged from the chamber.

Abstract: A method for processing residual liquids comprising organic complexes of heavy metals, sulphur and nitrogen compounds and amongst others originating from fixing baths and the like of the photographic and photochemical industries, whereby the residual liquid is sprayed in at least one spraying chamber or area with addition of nitrates and calcium ions into a hot, oxidizing gas flow, in particular originating from industrial installations or combustion furnaces.

Abstract: In a method of recovering silver from an aqueous suspension, the suspension is admixed with a solution capable of converting silver halide to metallic silver to cause flocculation of the silver, the flocculated silver is separated from the aqueous phase, and the silver is recovered.

Abstract: Equipment and methods for an efficient, low cost silver recovery apparatus for recovering silver from a silver-containing solution. The apparatus comprises a replaceable silver recovery subassembly, stackable container, lid, lock ring which is locked or sealed to make the container tamperproof, and an L-shaped connector by which an anodic silver reducing, hollow core metal coil in the replacement subassembly is releasibly connected to an effluent port of the recovery apparatus. The silver recovery subassembly comprises a mesh bag which is a carrier of the metal coil and containment filter for influent sludge and particulates produced during silver reduction. The mesh bag, with support by the container and lid provides a capturing net for incoming sludge as well as particulates which form during the silver reduction process.

Abstract: A method to reduce dissolved silver present in spent, waste, photographic processing fluids containing thiosulfate, is described. This process involves adjusting the pH to a low level prior to the addition of finely ground steel to the solution. With the pH at the low level, e.g. 2.5, the reaction of dissolved silver to precipitated silver, is facilitated. However, the pH must then be raised or neutralized, e.g. 7-8.5, in order to insure that the dissolved silver is essentially all precipitated. This material can now be safely shipped without treatment as a hazardous material and, after filtering the solids therefrom, can be safely disposed.

Abstract: A method is disclosed for the quantitative removal and concentration of desired transition metal ions from a source solution which may contain larger concentrations of other metal and H.sup.+ ions. The method comprises bringing the source solution into contact with a compound comprising a pyridine containing ligand covalently bonded through an organic spacer silicon grouping to a solid inorganic support. The pyridine portion(s) of the compound has an affinity for the desired metal ions to form a complex thereby removing the desired metal ions from the source solution. The desired metal ions are removed from the compound by contacting the compound with a much smaller volume of a receiving solution having a greater affinity for the desired metal ions than does the pyridine ligand portion of the compound. The concentrated metal ions thus removed may be recovered by known methods.

Abstract: A system for recovering silver from photographic film comprises a wash mixer adapted to hold the film and wash water comprising water, a proteolytic enzyme and a floculant. The mixer is adapted to rotate about its longitudinal axis and comprises spiral fins disposed at the inside surface thereof and a swivel joint coaxial with the axis of rotation.

Abstract: A non-toxic process for the recovery of silver from silver containing photographic emulsion coated paper or film substrates is provided. The process includes the use of a stripping formulation comprised of an alkaline bleach solution which is capable of holding stripped animal protein, silver and silver halide in solution during separation of the substrate materials. The solution containing the silver, silver halide and animal protein is treated with a strong or highly ionized acid which results in controlled precipitation of hydrolyzed animal protein, silver and silver halide. Waste fluids are neutralized with an alkali metal hydroxide, the precipitate is dried to a sludge, carbon content of the sludge is control burned and the residue is smelted with appropriate fluxes in order to achieve silver ingot.

Abstract: A silver controller comprising a container, a core member fitted within the container, a filler material around the core member, and a fluid deflector extending around the filler material. The container has an inlet and an outlet and a base. The inlet is located at a higher level than the outlet. The core member has an aperture that is distal the base. The core member has a flange that extends outwardly above the aperture of the core member. The filler material is a metal above silver in the electromotive force series. The fluid deflector is connected to the flange and extends downwardly therefrom so as to be below the aperture in the core member. A plating shield is placed exterior of the fluid deflector. The plating shield is connected to the flange member at one end and generally abuts the bottom of the container at the other end. The plating shield is of a perforated metal suitable for allowing the passage of fluids therethrough.

Abstract: An improved canister for the recovery of silver from acidic, waste fluids is described. This canister comprises both inner and outer element, each removable from the other, with fitted top and bottom sections. The novel canister thus described, provides a rapid flow of waste material through the system and is efficient and easy to use and manufacture than prior art elements. Plugging of the canisters due to intermittent use is also reduced in the element of this invention.

Abstract: A sealed, pressurized system for processing silver bearing solutions, such as photographic solutions, for the purpose of removing the silver comprises a series of interconnected sealed containers each of which contains several spaced apart reels or masses of steel wool through which the silver bearing solution is slowly pumped under pressure and intermittently.