Abstract: An improved method for processing of nickel-bearing ores, particularly saprolite and limonite, to recover the valuable minerals contained therein, comprising leaching the ore with nitric acid to form a slurry; separating the iron values by precipitation, removing the iron values; forming a liquid/solid residue in which nickel, cobalt and magnesium are in solution, and manganese and aluminum, when present, are solid residues in oxide form; conducting a liquid-solid separation and removing the solids; and recovering the nickel, cobalt, and manganese from the liquid-metal concentrate. The leachate is recovered and nitric acid from the leachate is recycled.

Abstract: Disclosed is a method of efficiently leaching copper not only from a readily-soluble copper ore but also a poorly-soluble copper sulfide ore partially containing or consisting of chalcopyrite and/or covellite by means of ore heap leaching under versatile conditions for actual operation. Also disclosed is a method of leaching copper from a copper sulfide ore, including leaching copper from an ore including a copper sulfide ore by heap or dump leaching with the use of a sulfuric acid solution containing ferric (III) ions and iodide ions at a total iodine concentration of 8 to 100 mg/L as a leaching solution.

Abstract: Apparatus and methods for mercury and precious metal recovery are provided. The apparatus includes a granulometric separator for separating a feed by particle size; a centrifugal concentrator in flow communication with the granulometric separator for isolating and concentrating an elemental mercury-containing fraction of the feed; and an accumulator tank for collecting elemental mercury from the elemental mercury-containing fraction. The accumulator tank has an inlet in flow communication with the centrifugal concentrator; an outlet; a plurality of baffles defining a serpentine flow path to slow the flow of the elemental mercury-containing fraction from the inlet to the outlet; and a mercury accumulation area for collecting elemental mercury settling from the elemental mercury-containing fraction.

Abstract: The invention relates to a method for removing silver from a chloride solution in a copper recovery process. According to this method, silver is removed using fine-grained copper powder and mercury. Silver removal occurs in at least two stages and mercury is fed into the solution at a certain molar ratio with regard to the silver in the solution.

Abstract: Processes for extracting and recycling alkali metal compounds present in the char produced from the catalytic gasification of carbonaceous materials are provided involving at least contacting the char with and alkali metal hydroxide followed by carbon dioxide. Both the alkali metal hydroxide and carbon dioxide treatments serve to convert at least a portion of the insoluble alkali metal compounds in the char into soluble species which can be recovered and recycled.

Abstract: Mercury is removed from solutions contaminated with mercury, the solution contaminated with mercury being introduced into a distillation column above the column bottom, solvent being distilled off and solution depleted in mercury being stripped off at the column bottom.

Abstract: A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

Abstract: Process for removing mercury from flue gases of high-temperature plants, in particular power stations and waste incineration plants in which a bromine compound is fed to the multistage furnace and/or the flue gas in a plant section downstream of the furnace, the temperature during contact of the bromine compound with the flue gas being at least 500° C., preferably at least 800° C. The combustion is carried out in the presence of a sulphur compound, in particular sulphur dioxide. Subsequently to the furnace, the flue gas is subjected to an optional multistage cleanup for removing mercury from the flue gas, which cleanup comprises a wet scrubber and/or a dry cleanup.

Abstract: A method for stabilization of liquid mercury in which powdered copper particles are cleaned with a chemically reactive fluid suitable for removing surface oxidation from the surface. “Clean” powdered copper particles are mixed with liquid mercury to form a powdered copper/liquid mercury mixture. The mixture is then hardened to form an amalgam. Amalgams in which the amount of mercury is greater than 50% by weight of the total amalgam may be produced in accordance with the method of this invention.

Abstract: Mercury salt-containing discharge effluents such as from B-5 fixatives and PVA fixatives are treated to remove mercury therefrom. The present method contemplates plates the addition of aluminum to the effluent to cause the precipitation of elemental mercury therefrom. The remaining effluent, after precipitation, can be decanted and post treated while recovering precipitated elemental mercury. The decanted effluent, once subjected to post treatment, by first rendering the effluent highly basic, is the neutralized. Neutralization causes the precipitation of sodium chloride. A water conditioner is then added thereto. Subsequently, the so-treated decanted effluent is then filtered through a filtering medium such as filter paper or the like. A second filtration step may then be carried out by passing the so-filtered effluent through a mixed bed or through a filter paper.

Abstract: A three-stage process for removing mercury contaminants from alcoholic alkali metal alkoxide solutions is provided, in which mercury is depleted in a first filtration through inert fibrous material, followed by a second filtration through pulverized coal, and then by concentration by distillation, to preferably provide a mercury content below 0.1 ppm.

Abstract: The present invention relates to a process for cleaning mercury-contaminated soils that is simple, efficient and safe to use. This process can also be used to clean soils contaminated with additional metals, such as zinc, copper and lead, at a lower pH. The invention involves treating contaminated soils with solid hypochlorite in a continuous counter-current process.

Abstract: In a process for decontaminating suspensions containing silt, pollutants and water, particularly mercury and hydrocarbon pollutants, the suspensions are heated under pressure to boiling temperature, then passed through a throttling device wherein the pressure is reduced so that, by flashing, a three-phase mixture comprising steam, residual water and solids is formed which mixture is then superheated in a pipe reactor whereby the pollutants are enriched in the steam phase, the solids are then separated out of the mixture and the steam phase is condensed for collection of the pollutants with the condensate.

Abstract: The present invention relates to a process for cleaning mercury-contaminated soils that is simple, efficient and safe to use. This process can also be used to clean soils contaminated with additional metals, such as zinc, copper and lead, at a lower pH. The present invention involves screening the contaminated soil to remove unwanted materials, leaching the contaminated soils with hypochlorite in a screw reactor, thickening, leaching with hypochlorite and sodium chloride, thickening again and then separating the mercury-containing liquids from the clean soil. This invention also relates to a process which uses sulfide to treat the mercury-containing liquids.

Abstract: A process for the recovery of mercury from mercury-containing caustic sludge, generated from a mercury cell, chlor-alkali plant, wherein mercury is removed from the caustic sludge by treatment in a hydraulic mineral separator. The process provides a ready method for removal of mercury from caustic sludge which can allow recovery of the mercury for re-use. Alternatively, the process provides a smaller volume of mercury-contaminated material to be treated and/or land-filled.

Abstract: A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents.

Abstract: Heavy metals are efficiently removed from contaminated soil by a process which comprises leaching or washing the soil with a mild leachant solution comprised of an aqueous solution of an acid and a salt. Heavy metals are also efficiently removed from paint chips by washing with an aqueous acid. The heavy metals are recovered from the leachant be cementation.

Abstract: A method for processing hetrogeneous metal-containing deposits recovered from the cleaning of synthesis gas produced during the thermal treatment of wastes containing metals, including volatile metals, in equipment having a heating enclosure and a waste liquid container. The method comprises the steps of directing all of the liquids and residual solutions to the waste liquid container and directing all of the residual gases into the heating enclosure.

Abstract: Heavy metal values can be removed and separated from a substance having a suitable amount of the heavy metal values by contacting the substance with a fluid containing sulfur trioxide to prepare a corresponding heavy metal sulfate, which is followed by leaching the sulfate therefrom and separating the leached sulfate. For example, mercury metal, oxide or sulfide, or methyl mercury, such as can be found in used fluorescent lamps and household batteries, in industrial flue sands, fly ash, contaminated soils, etc., can be removed by contact of crushed lamps or batteries, samples of the flue sands, fly ash, or contaminated soils, etc., with a mixture of sulfur trioxide in air to form mercuric sulfate, which is leached with a suitable leaching agent such as water, aqueous hydrochloric acid, hot dilute sulfuric acid, or concentrated sodium chloride solution, and sequestered by use of an ion exchange resin or precipitated as sulfides for further isolation of mercury value.

Abstract: A method for eliminating mercury from mercury containing liquids by contacting the mercury-containing liquid with a plurality of fibers wherein the fibers making up the plurality of fibers have a coating of silver on the surface of the fibers, and a silver-coated fiber for use in the method are disclosed.

Abstract: This invention relates to a hydrometallurgical process for the treatment of mercury contaminated muds. More particularly, this process pertains to a hydrometallurgical process for the treatment of Environmental Protection Agency designated K106 muds discharged from a mercury chlor-alkali plant.

Abstract: Describes a process for separating metallic mercury from soil containing same by producing an aqueous pulp of the contaminated soil in a mixing tank (12), screening the pulp in screening means (14) to separate a coarse fraction, further screening the pulp in screening means (17) (19) to produce a fines fraction, charging said fines fraction to solid-solid separating means (20) (24) to provide a first aqueous soil slurry (83) that is substantially free of metallic mercury and a second aqueous soil slurry (75) (81) containing metallic mercury, charging the second aqueous soil slurry to froth flotation cell means (28), thereby to provide a metallic mercury-containing froth (90) and an aqueous soil slurry (87) substantially free of metallic mercury, removing the froth from the flotation cell, and separating metallic mercury that settles out of the froth (95). Soil slurry substantially free of metallic mercury is flocculated (32), dewatered (35), filtered (36) and removed to a landfill (9).

Abstract: A process is described for treating spent batteries of any type, comprising essentially the following stages:a) disintegrating the spent batteries in water to a piece size of less than 7 mm followed by stirring in water, then screening to obtain a pulverlent aqueous turbid fraction (underscreen fraction) and a coarse fraction (overscreen fraction);b) stirring the pulverulent aqueous turbid fraction at a pH of between 7 and 8, followed by filtering by which the solids are separated from the aqueous solution, which is fed to water treatment;c) removing mercury both from the coarse fraction of point a) and from the separated solids of point b) in an indirectly heated continuously rotating mercury removal furnace operating in total absence of air and to which calcium hydroxide has been added, to obtain residues essentially free of mercury.

Abstract: A process and solution for transforming insoluble mercury metal into a soluble compound. The process includes oxidizing elemental mercury to form mercury cations, contacting the mercury cations with a complexing agent to form a soluble complex, and dissolving the soluble complex with a solvent. The solution contains an oxidizing agent, a complexing agent and a solvent.

Abstract: This invention relates to a hydrometallurgical process for the treatment of mercury contaminated muds. More particularly, this process pertains to a hydrometallurgical process for the treatment of Environmental Protection Agency designated K106 muds discharged from a mercury chlor-alkali plant.

Abstract: In a method of recovering elemental mercury from soil, the soil contaminated with elemental mercury is first sized in a screening and pressure-washing step. The fine soil particles which pass through the screening device contain essentially all of the elemental mercury. The screened soil particles are fed in the form of a slurry into a gravitational separator. The resulting soil tailings and discharged and a residue comprising heavy materials and elemental mercury is then fed into a gravitational concentrator for a further separation step. The method allows the recovery of more than 99.5% of elemental mercury.

Abstract: Insoluble mercury salts and any mercury in mercury-containing material are converted into a soluble form by controlled chlorination. The soluble forms of mercury in the chlorination solution are reduced with iron, preferably iron powder, to elemental mercury. After separation from the reduced solution, the solids from the reduction containing entrained mercury, are subjected to a separation for the separation and substantially quantitative recovery of substantially pure mercury. Separation by elutriation through a body of mercury is preferred. Prior to separation, the reduction solids may be kneaded for coalescence of fine mercury particles, followed by slurrying of the kneaded material. Any selenium in the reduced solution may be recovered in a reduction with a suitable reductant, preferably by adding strong sulfuric acid in the presence of the ferrous chloride formed in the preceding reduction, and excess sulfur dioxide.

Abstract: The effluent from mercury collected during the photochemical separation of the .sup.196 Hg isotope is often contaminated with particulate mercurous chloride, Hg.sub.2 Cl.sub.2. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg.sub.2 Cl.sub.2 contaminant. The present invention is particularly directed to such filtering.

Abstract: Process for removing mercury from flue gases of high-temperature plants, in particular power stations and waste incineration plants in which a bromine compound is fed to the multistage furnace and/or the flue gas in a plant section downstream of the furnace, the temperature during contact of the bromine compound with the flue gas being at least 500° C., preferably at least 800° C. The combustion is carried out in the presence of a sulphur compound, in particular sulphur dioxide. Subsequently to the furnace, the flue gas is subjected to an optional multistage cleanup for removing mercury from the flue gas, which cleanup comprises a wet scrubber and/or a dry cleanup.