Abstract: This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

Abstract: A compound heavy metal chelating agent, which relates to the field of chemical and environmental protection technology, includes dithiocarboxylate functionalized ethoxylated pentaerythritol core hyperbranched polymer and alkylene diamine-N,N?-sodium bisdithiocarboxylate with a molar ratio in a range of 1:1.0 to 1:10.0. The two different structural types of components have the synergistic positive effect. While chelating heavy metals, the compound heavy metal chelating agent alternately combine with heavy metals to form insoluble chelating super-molecular deposits, which has both chelation and flocculation functions. The compound heavy metal chelating agent meets the standard for treating heavy metal wastewater, and low concentration heavy metal wastewater. It has a wide adaptability range, and does not need to add coagulant. Moreover, it is simple in preparation method, easily available for raw materials, low in cost, and easy to be industrialized.

Abstract: An ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group and its applications as a heavy metal chelating agent are disclosed, which relates to the field of chemical and environmental protection technology. The hyperbranched polymer has a chemical formula of C[CH2OCH2CH2OCOCH2CH2N(CSSM)CH2CH2NHCSSM]4, wherein M is Na+, K+ or NH4+. A preparation method of the hyperbranched polymer is simple, the raw materials are easily available, and it is easy to be industrialized. The hyperbranched polymer is able to be used as a heavy metal chelating agent. Its special three-dimensional space structure is able to alternately chelate with heavy metals to form a large three-dimensional molecular conjugate with low solubility, strong stability, and compactness, which is able to effectively treat wastewater and waste containing heavy metals.

Abstract: Disclosed herein is a treated ore solid comprising a reduced amount of a contaminant, for example arsenic, compared to the ore solid prior to treatment. Also disclosed are temperature and pressure modifications, parameters, and methods for treating an ore solid by pressure oxidation leaching of enargite concentrates. The disclosed methods and processes may be applied to copper sulfide orebodies and concentrates containing arsenic. In some cases, the disclosed methods and systems extract, remove, or reduce contaminants, for example arsenic, from an ore containing solution at moderately increased temperature, pressure, and oxygen concentration, and in the presence of an acid.

Abstract: The present invention relates to a process for the selective and ecoefficient recovery of lead and silver jointly as a concentrate product from hydrometallurgical residues.

Abstract: A polymer, a composition, and uses for either are disclosed. The polymer is derived from at least two monomers: acrylic-x and an alkylamine, and has attached to the polymer backbone a functional group capable of scavenging at least one metal. The polymer has a polymer backbone with a fluorescing quantity of conjugated double bonds, thereby providing a method for controlling metal scavenging via fluorescence. These polymers have many uses in various media, including wastewater systems.

Abstract: Systems and methods for removing impurities from a feed fluid in a single vessel. A method generally includes, in single vessel, contacting a feed fluid passing through the vessel with a copper-based material for removing oxygen from the feed fluid; and contacting the feed fluid passing through the vessel with an adsorbent for removing at least one of water, carbon dioxide, and oxygenated hydrocarbons from the feed fluid.

Abstract: A method and composition for the reduction of the emission of selenium into the environment from the burning of fossil fuels with the use of two chemistries, either individually or in combination with each other. The method uses polydithiocarbamic compounds, including polydithiocarbamic compounds derived from a polymer produced from acrylic-x and alkylamine in conjunction with a scrubber process to capture selenium and reduce its emission in aqueous phase blowdown. The method and composition also helps reduce corrosion in the scrubber process.

Abstract: A composition comprising a polymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals is disclosed. These polymers have many uses in various mediums, including wastewater systems.

Abstract: A method for selectively processing a polymetallic oxide solution containing a plurality of base metals comprising at least one of: Cu, Co, Ni, Zn associated with iron, comprising acid leaching the solution; recovering a filtered leachate; oxidizing the leachate; and adjusting the pH of the leachate in presence of a complexing agent; wherein the acidic solution is one of: i) a hydrochloric acid solution and ii) a sulfuric acid solution at a pH lower than about 1.5, and the complexing agent is one of: i) ammonium chloride and ii) ammonium sulfate, the step of adjusting the pH comprising raising the pH to a range between about 2.5 and about 3.5.

Abstract: Provided is a manufacturing device of an aluminum nitride single crystal including a crucible. An aluminum nitride raw material and a seed crystal are stored in an inner portion of the crucible. The seed crystal is placed so as to face the aluminum nitride raw material. The crucible includes an inner crucible and an outer crucible. The inner crucible stores the aluminum nitride raw material and the seed crystal inside the inner crucible. The inner crucible is also corrosion resistant to a sublimation gas of the aluminum nitride raw material. The inner crucible includes either, a single body of a metal having an ion radius larger than an ion radius of an aluminum, or includes a nitride of the metal. The outer crucible includes a boron nitride. The outer crucible covers the inner crucible.

Abstract: A method and composition for the reduction of the emission of selenium into the environment from the burning of fossil fuels with the use of two chemistries, either individually or in combination with each other. The method uses polydithiocarbamic compounds, including polydithiocarbamic compounds derived from a polymer produced from acrylic-x and alkylamine in conjunction with a scrubber process to capture selenium and reduce its emission in aqueous phase blowdown. The method and composition also helps reduce corrosion in the scrubber process.

Abstract: Processes for improving copper/iron selectivity in a solvent extraction circuit by contacting an acidic aqueous solution containing dissolved copper and iron ions with a solvent extraction composition including an orthohydroxyaryloxime, a selectivity modifier, and an equilibrium modifier, wherein the ratio of selectivity modifier to orthohydroxyaryloxime is from 0.001 to 0.05, thereby decreasing the copper:iron transfer ratio, are provided herein.

Abstract: A Cu2O spherical assembly particle composition is composed of Cu2O spherical assembly particles, each of which is formed by agglomerating a plurality of Cu2O ultrafine particles that have an average diameter in the range from 1 to 100 nm and a standard deviation on the diameter in the range from 0 to 10%. The Cu2O spherical assembly particles have an average diameter in the range from 0.1 to 10 ?m and a standard deviation on the diameter in the range from 0 to 40%. This Cu2O spherical assembly particle composition is composed of Cu2O assembly particles with excellent uniformity, so it shows excellent properties such as realizing a good electric conductivity during a curing process for wiring. Accordingly, the spherical Cu2O assembly particle composition may be usefully used as precursors for solar energy conversion, magnetic storage medium, catalyst, gas sensor, and copper wire formation.

Abstract: A method of preparing basic metal carbonate selected from the group consisting of zinc carbonate, nickel carbonate, silver carbonate, cobalt carbonate, tin carbonate, lead carbonate, manganese carbonate, lithium carbonate, sodium carbonate, and potassium carbonate from metals comprising: contacting the metal with an aqueous solution comprising an amine, carbonic acid, and oxygen under conditions where the metal is converted into basic metal carbonate; and recovering the basic metal carbonate.

Abstract: A cleaning agent for a silver-containing composition is provided which can readily remove silver adhered to an object to be cleaned with excellent operability and low environmental loads. This cleaning agent for the silver-containing composition includes an iron nitrate aqueous solution and used to remove silver derived from a composition containing silver nanoparticles having an average diameter of 1 nm to 100 nm adhered to the object to be cleaned.

Abstract: Uses for a composition comprising a polymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals are disclosed. These polymers have many uses in various mediums, including wastewater systems.

Abstract: A process for recovering a metal chloride or mixed metal chloride from a solid waste material comprising recoverable metal containing constituents produced by lead, copper or zinc smelting and refining processes, said process comprising the steps of: (i) heating the solid waste material; (ii) treating the heated material of step (i) with a gaseous chloride to form a gaseous metal chloride containing product; and (iii) treating the gaseous metal chloride containing product of step (ii) to recover the metal chloride or mixed metal chloride. The metal chloride may be further treated to extract the metal itself.

Abstract: The invention relates to a process for separating, in an aqueous medium, at least one actinide element from one or more lanthanide elements by using at least one molecule which sequesters the said actinide element to be separated and membrane filtration, the said process successively comprising: a) a step of bringing at least one molecule which sequesters the said actinide element in contact with the aqueous medium, the said molecule not being retained in the non-complexed state by the said membrane and being capable of forming a complex with the actinide element to be separated, comprising the said element and at least two of the said sequestering molecules, which complex is capable of being retained by the membrane; b) a step of passing the aqueous medium over the membrane in order to form a permeate on one side, comprising an aqueous effluent depleted of the said actinide element, and a retentate comprising the said complex.

Abstract: Disclosed is a method of manufacturing a metal oxide nano powder comprising preparing a first dispersed solution by adding a nano-sized metal powder to water and dispersing the metal powder within the water, performing a hydration reaction of the first dispersed solution at a temperature of about 30 to about 70° C. to generate a precipitation, and filtering and drying the precipitation to prepare a metal oxide powder. Also, disclosed is a metal oxide nano powder manufactured by the method described above, and having any one of a bar-form, a cube-form, and a fiber-form.

Abstract: The present invention relates to a process for separating at least one first substance from a mixture comprising this at least one first substance and at least one second substance, comprising the steps of (A) bringing the mixture comprising at least one first substance and at least one second substance into contact with at least one surface-active substance, (B) if required, addition of at least one dispersing medium to the mixture obtained in step (A) in order to obtain a dispersion, and (C) separation of the adduct of at least one first substance and at least one surface-active substance from the dispersion from step (A) or (B), for example by means of flotation, at least one additive which is either a monomolecular compound comprising amino and carboxyl groups or derivatives thereof or a polymeric compound obtainable by reaction of alkylene oxides and/or aziridines, or mixtures thereof, being added to the mixture comprising at least one first substance and at least one second substance.

Abstract: A process for the recovery of a metal sulfide from a metal ion containing solution, including the steps of: a) providing a slurry containing seed panicles of said metal sulfide; h) adding a sulfide ion containing solution to said slurry to form an activated seed slurry; c) mixing said activated seed slurry with said metal ion containing solution to thereby form a metal sulfide precipitate; and d) recovering said metal sulfide precipitate.

Abstract: A hydrometallurgical process for the recovery of metals selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, and gold (PM) from solids includes dissolving the PM and base metals in an acidic halide aqueous solution and precipitating the PM using substituted quaternary ammonium salts (SQAS). PM having multiple oxidation states may be oxidized or reduced to separate through differential solubility. Au-SQAS is separated by washing the precipitate with a suitable organic solvent. Rh-SQAS and other PM with multiple oxidation states are dissolved in a strong halide acid solution and oxidized to separate soluble Rh. Pb and Pd are separated by boiling the initial acidic halide aqueous solution of metals in an excess of SQAS. The Pb and Pd filtrate is oxidized and then Pd-SQAS is dissolved in aqueous ammonia and separated from insoluble Pb. A slurry of Ir-SQAS and Pt-SQAS are separated through dissolution of Ir-SQAS with NaNO2.

Abstract: An aqueous precipitation process for the preparation of particles comprising primarily silver sulfate, comprising reacting an aqueous soluble silver salt and an aqueous soluble source of inorganic sulfate ion in an agitated precipitation reactor vessel and precipitating particles comprising primarily silver sulfate, wherein the reaction and precipitation are performed in the presence of an aqueous soluble inorganic additive compound containing a cation capable of forming a sulfate salt that is less soluble than silver sulfate or a halide anion or an oxyanion capable of forming a silver salt that is less soluble than silver sulfate, the amount of additive being a minor molar percentage, relative to the molar amount of silver sulfate precipitated, and effective to result in precipitation of particles comprising primarily silver sulfate having a mean grain-size of less than 70 micrometers.

Abstract: This invention relates to the synthesis and isolation of colloidal silver particles through the use of thermomorphic polymers and the resulting composition. It further relates to the use of the resulting composition in the preparation of inks for printing with silver-containing inks.

Abstract: The present invention relates to a process for the removal of metal catalyst degradation products from a bleed stream of a catalytic chemical reaction process, wherein the catalyst is based on a metal selected from those in group VIII of the periodic table, chromium, copper, molybdenum, tungsten, rhenium, vanadium, titanium and zirconium, said process comprising treatment of the bleed stream with an alkali metal carbonate or ammonium carbonate source to form a solid complex or an aqueous solution of said solid complex, and removal of the solid complex or the aqueous solution of said solid complex from the bleed stream.

Abstract: A fuel cell includes an anode, a cathode, and an electrolyte membrane arranged between the anode and the cathode. A fuel deficiency countermeasure is implemented for the anode and a fuel deficiency countermeasure is implemented for the cathode. As a result, the fuel cell suppresses a decline in performance caused by a fuel deficiency.

Abstract: A method for processing waste copper liquid produces high copper content sludge, mainly by recycling a low copper content waste liquid from production of PCB in order to discharge a comparatively higher copper content sludge. First, the waste liquid is classified into an acidic low concentration copper waste liquid, an acidic high concentration copper waste liquid, and an oxidized acidic high concentration copper waste liquid. Then mix with a strong alkali to react and form a cupric oxide sludge that then undergoes dehydration and baking by applicable equipment to remove water and get a higher copper content sludge. It is therefore unnecessary to add other conversion agents to convert copper hydroxide into cupric oxide, thereby turning the valueless low copper content sludge from a waste liquid into a valuable recyclable high copper content sludge.

Abstract: A method for manufacturing metal nanoparticles, the method including forming a mixture by dissociating a metallic salt of a metal selected from the group consisting of Ag, Pd, Pt, Au and an alloy thereof as a metal precursor in fatty acid; and adding a metallic salt of a metal selected from the group consisting of Sn(NO3)2, Sn(CH3CO2)2, and Sn(acac)2 as a metallic catalyst into the mixture and mixing the mixture and the metallic salt. According to the method, metal nanoparticles have a uniform particle size distribution and a high yield by performing in a non-aqueous environment without using any organic solvent, and are environmentally friendly due to no use of a reducing agent.

Abstract: The present invention is directed to the use of a combination of a polymeric chelant and coagulant to treat metal containing wastewater. More particularly, the invention is directed at removing copper from CMP wastewater. The composition includes a combination of (a) a polymeric chelant derived from a polyamine selected from the group consisting of diethylenetriamine (DETA), triethylenetetraamine (TETA), tertraethylenepentaamine (TEPA), poly[vinylamine], and branched or linear poly[ethylenimine] (PEI); and (b) a water soluble or dispersible copolymer of a tannin and a cationic monomer selected from the group consisting of methyl chloride or dimethyl sulfate quaternary salt of dimethyl aminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminopropyl methacrylamide, dimethylaminopropyl acrylamide, and diallyl dimethyl ammonium chloride.

Abstract: The invention relates to a method for the treatment of material containing at least one valuable metal and arsenic to form a valuable metal-depleted scorodite sediment and a pure aqueous solution to be discharged from the process. According to the method, the valuable metals are first removed from the material to be treated and then arsenic precipitation from the solution is performed in two stages. By means of the method, the aim is to obtain as low a valuable metal content as possible in the scorodite sediment that will be formed. Likewise, the arsenic and valuable metal content of the aqueous solution that is formed during arsenic precipitation also remains so low that the water can be released into the environment.

Abstract: The present invention relates to a method for manufacture of silver-based composite powders for electrical contact materials. The invention relates also to electrical contact materials made from such composite powders. The process comprises a high energy dispersing process of wet silver oxide (Ag2O) with additional second oxide components in aqueous suspension. The high energy dispersing process can be conducted by high shear mixing or by high energy milling. Preferably high speed dispersing units working at rotating speeds in the range of 5,000 to 30,000 rpm or high energy mills such as attritor mills are used. The new process is versatile, economical and offers access to a broad spectrum of contact materials. The silver-based composite powders made according to the new process yield contact materials with a highly dispersed microstructures and superior material characteristics.

Abstract: A method for extraction a metal from a mineral ore including a refractory ore contained in a metal. The method includes concentration of refractory ore followed by micronization of the concentrate until gold is liberated by the extraction solution and mixing of micronized concentrate with concentration rejects or by-products to facilitate recovery of the treatment solution.

Abstract: A chemical process to leach copper concentrates in the presence of a concentrated solution of sulfates and chlorides. The process includes forming a high reactivity chemical paste containing a high concentration of ions in the liquid phase of the paste which react with copper ores and forms a series of soluble salts. The salts are extracted by a simple wash. Mixing equipment for handling high viscosity liquids is used. The total mixing time is about 5 minutes, after which the paste is poured into a rectangular mold, of several hundred meters per side, and is left to settle and breathe. During settling, water and sulfuric acid are added at intervals to replace that consumed by the reactions taking place during the aeration, until the reactions have virtually end. This treatment results in a dry, very resistant mass, containing the copper extracted in form of chlorine salts, and sulfate.

Abstract: An aqueous precipitation process for the preparation of particles comprising primarily silver sulfate, comprising reacting an aqueous soluble silver salt and an aqueous soluble source of inorganic sulfate ion in an agitated precipitation reactor vessel and precipitating particles comprising primarily silver sulfate, wherein the reaction and precipitation are performed in the presence of an aqueous soluble inorganic additive compound containing a cation capable of forming a sulfate salt that is less soluble than silver sulfate or a halide anion or an oxyanion capable of forming a silver salt that is less soluble than silver sulfate, the amount of additive being a minor molar percentage, relative to the molar amount of silver sulfate precipitated, and effective to result in precipitation of particles comprising primarily silver sulfate having a mean grain-size of less than 70 micrometers.

Abstract: This invention relates to the synthesis and isolation of colloidal silver particles through the use of thermomorphic polymers and the resulting composition. It further relates to the use of the resulting composition in the preparation of inks for printing with silver-containing inks.

Abstract: A silver oxide powder that replaces silver powder as a silver conductive paste filler has a specific surface area measured by the BET method is 1.0–25.0 m2/g, average primary particle diameter is 1–50 nm, and average secondary particle diameter is 1–1000 nm. The silver oxide powder is made by preparing a neutralization medium that is an aqueous solution containing one or both of sodium hydroxide and potassium hydroxide in a total amount of 0.5 mole/L or less, simultaneously adding an aqueous solution containing silver salt in an amount of 6.0 mole/L or less and an aqueous solution of at least one of sodium hydroxide and potassium hydroxide to the liquid medium to conduct a neutralization reaction, thereby obtaining a neutralized precipitate, maintaining the liquid at a pH in the range of 12±1.5 during the reaction, and subjecting the precipitate to filtration, washing, and drying.

Abstract: A method for producing a copper/palladium colloid catalyst useful for Suzuki couplings.

Abstract: The present invention provides silver oxide particles having an average diameter of less than or equal to 100 nm that are stable and can be transported in dry powder form. The surface of the silver oxide particles is coated with an extremely thin layer of a surfactant such as fatty acid. Nanosized silver oxide particles according to the invention are preferably formed via the addition of a strong base to a mixture including an aqueous silver salt solution and a surfactant dissolved in an organic solvent that is at least partially water miscible. The strong base causes silver oxide to precipitate from the mixture as nanosized particles, which are immediately encapsulated by the surfactant and thus protected from further crystal growth and Ostwald ripening. The nanosized surfactant coated particles of silver oxide can be washed and dried and then transported in dry form.

Abstract: This invention provides a method for preparing cerium oxide nanoparticles with a narrow size distribution. The cerium oxide nanoparticles obtained by the method of the invention are nearly all crystalline. The method comprises providing a first aqueous solution comprising cerium nitrate and providing a second aqueous solution comprising hexamethylenetetramine. The first and second aqueous solutions are mixed to form a mixture, and the mixture is maintained at a temperature no higher than about 320° K to form nanoparticles. The nanoparticles that are formed are then separated from the mixture. A further aspect of the present invention is an apparatus for preparing cerium oxide nanoparticles. The apparatus comprises a mixing vessel having a first compartment for holding a first aqueous solution comprising cerium nitrate and a second compartment for holding a second aqueous solution comprising hexamethylenetetramine. The mixing vessel has a retractable partition separating the first and second compartments.

Abstract: The oxide materials are of the class of ternary mesoporous mixed oxide materials including lanthanum, a metal M selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu and Zn, and zirconium or cerium such a mesoporous La—Co—Zr mixed oxide material designated as Meso LCZ[x] where x is the atomic ratio (La+Co)/La+Co+Zr. They are useful as catalysts since they show high activities for hydrocarbon oxidation and good resistance against poisoning agents. These highly ordered mesoporous mixed oxides are synthesized by: preparing an amorphous solution of a La-M precursor and adding a salt of zirconium or cerium thereto; acidifying the amorphous solution in the presence of a surfactant under conditions to obtain a clear homogeneous solution; adjusting pH of the solution under conditions to form a solid precipitate; separating the solution and surfactant from the precipitate; and calcinating the precipitate.

Abstract: Copper is extracted from aqueous copper leach solutions wherein the leach solutions have a temperature of at least 30° C.

Abstract: The invention provides a method of recovering a copper component or a manganese component from a cleaning agent containing copper oxide, a cleaning agent containing basic copper carbonate, a cleaning agent containing copper hydroxide, or a cleaning agent containing copper oxide and manganese oxide, the cleaning agents having been used for removing, through contact with a harmful gas, a phosphine contained as a harmful component in the harmful gas. Also, the invention provides a method of recovering a copper component or a manganese component from a cleaning agent containing basic copper carbonate, a cleaning agent containing copper hydroxide, or a cleaning agent containing copper oxide and manganese oxide, the cleaning agents having been used for removing, through contact with a harmful gas, a phosphine contained as a harmful component in the harmful gas.

Abstract: A method for recycling copper oxide includes: a first step in which a sodium hydroxide aqueous solution is added to acidic copper chloride waste etchant produced in the PCB industry, to obtain copper hydroxide slurry; and a second step in which the slurry obtained in the first step is heated and sintered to thereby prepare a needle-form copper oxide. Since copper oxide has a purity of more than 99.0 wt % and the needle-form crystal morphology, so that it has an excellent filtering ability and homogeneous particle size distribution.

Abstract: In a method of recovering copper from an industrial waste sludge or liquid, a first treatment agent and/or a second treatment agent is added into a waste feed to separate the coagulants therefrom. A bluish solution and a tail gas are thereby obtained. Alternatively, an acidic etching waste solution is added instead of the first treatment agent and/or the second treatment agent into the waste feed. Then, a converting agent/converting aid agent is added in the bluish solution. Thereafter, the solution is filtrated to obtain a solid copper oxide, a filtrate and a tail oxidizing gas. The filtrate is saturated by the aforementioned gases and fed back to the waste feed. The copper oxide thereby obtained has a high copper content compared to the conventional methods. All of the other resulting products are recycled without being disposed of in the environment.

Abstract: Stable copper hydroxide is prepared by removing ferrous ion from the beginning cupric solution. The ferrous ion is oxidized to ferric ion, and the ferric ion is precipitated by raising the pH of the solution to 3-4. The utilization of phosphate ion both increases the efficiency of oxidation and simultaneously precipitates ferric ion. A second raising the pH of the purified solution precipitates highly pure copper hydroxide that can be harvested.

Abstract: Methods for detecting gold and quantitating gold in ore samples utilizing a gold-specific protein are provided, including methods for multiple sample handling. Also provided are methods for extracting gold from mineral suspensions utilizing a magnetic mineral binding reagent and gold-specific protein, or hydrophobic reagent and gold-specific protein in conjunction with a flotation reagent.

Abstract: The present invention is directed to microemulsion techniques for rapidly preparing photochromic glass nanoparticles and to the photochromic glass nanoparticles so prepared. More particularly, the method of the invention comprises the combination of two microemulsions, one containing a water-soluble silver salt and a glass precursor and the other containing a halide salt and an initiator for glass formation, which process rapidly yields silver halide particles. This invention gives nanometer-sized silver halide particles embedded in glass, thus providing photochromic glass nanoparticles without further annealing, or at most mild annealing. These nanoparticles are valuable as added components to any macro-material that one might wish to have photochromic properties. The particles would impart photochromism while not affecting the physical properties of the material.

Abstract: Ozone is used to rapidly oxidize specific metallic elements. The insoluble oxidized compounds of the metals formed by the ozonation are then recovered for industrial use in a conventional sedimentation/filtration tank or pool. There is no requirement for pre-treating or neutralizing the acid mine discharge, even when iron is the dominant metal. If the pH of the untreated acid mine discharge is less than about 2.5, metals other than iron precipitated first. After that, the pH is raised and the iron is precipitated as ferric hydroxide. Aluminum is removed as hydrated aluminum compounds after removal of the iron prior to discharging the acid mine discharge to streams. Both the ozonation and neutralization processes are monitored and controlled using electrochemical sensors and feedback controllers.

Abstract: A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.