Abstract: A method for selectively extracting metal values from manganese bearing ores such as marine nodules. The ore is initially leached to solubilize manganese and other desirable metals as nitrates. The resulting solution is then treated with manganous hydroxide to selectively precipitate metals such as copper, nickel and cobalt. The enriched mixture of metal hydroxides is separated from the manganese nitrate solution, which is decomposed to recover high purity MnO.sub.2.

Abstract: A mixture of metal hydroxides is leached with an ammoniacal carbonate solution, to dissolve nickel, copper and zinc. Metal is recovered from the leaching solution. The solid leaching residue is leached with sulphuric acid at a pH of 1.5- 3, to dissolve a further amount of nickel, copper and zinc. The acidic leaching solution is passed to the ammoniacal leaching process.

Abstract: This invention provides a leaching procedure for manganese nodules for obtaining directly from a leaching stage all of the metal values, including manganese, utilizing an ammoniacal aqueous solution. The manganese nodules are reduced and then leached utilizing an ammoniated solution of an ammonium salt comprising at least about 150 grams per liter of ammonium ion and at least 0.83 Normal in the anion, other than hydroxyl. The resultant leach solution comprises the dissolved manganese, nickel, cobalt and copper values from the nodule ore, and can subsequently be treated, as by liquid ion exchange, to separate out the individual metal values.

Abstract: A method for the selective recovery of cadmium, nickel and cobalt from a nickel-cadmium battery waste which comprises:A. leaching the waste with an ammoniacal carbonate solution to form an aqueous ammoniacal carbonate solution containing cadmium, nickel and cobalt (II) ammine complexes and a leaching residue. Any iron in the waste is in the leaching residue.B. adding air to the aqueous ammoniacal carbonate solution to oxidize the cobalt (II) ammine complex to cobalt (III) ammine complex.C. contacting the resulting aqueous ammoniacal carbonate solution with a substantially water insoluble organic solution which contains a hydroxyoxime which forms a nickel compound readily soluble in the organic solution with any nickel present but which does not affect cadmium and cobalt (III). Nickel is thereby removed.D. precipitating the cadmium as a carbonate by removing ammonia from the aqueous ammoniacal carbonate solution and then removing the cadmium in the form of a carbonate.E.

Abstract: A method is provided for separating cobalt from a nickel solution containing cobalt in the cobaltous state and an ammonium salt comprising subjecting said solution containing at least 0.2 grams per liter of ammonium ion to ozonation while maintaining the pH thereof from about 4.5 to 6, until said cobalt has been oxidized to the cobaltic state and simultaneously precipitating said cobalt in the cobaltic state at a temperature ranging from about 10.degree. to 90.degree. C.

Abstract: In a process for treating manganese nodules wherein the nodules are reduced so as to convert most of the nickel, copper and cobalt impurities to their metallic state while inhibiting the conversion of the iron and manganese impurities to their metallic state, the resulting reduced ore is wet ground, if necessary, slurried and treated with an aqueous ammoniacal solution containing free oxygen to extract the metallic nickel, copper and cobalt as their ammine complexes. The iron and manganese are removed from the aqueous ammoniacal solution containing iron and manganese as impurities by leaching the slurry of reduced ore by adding sodium chloride or ammonium chloride thereto and blowing air in the leach solution which also contains sulfur dioxide.

Abstract: A process in which copper, nickel, cobalt and molybdenum are recovered by direct leaching of comminuted raw manganese nodules after the nodules are reduced in a reduction circuit with an aqueous ammoniacal leach solution containing cuprous ions. An improvement is disclosed which results from recycling a portion of the metal values recovered back to the reduction circuit as a solid basic metal carbonate. The metal carbonate recycle enables the size of the reactors in the reduction circuit to be reduced. The recycle also increases the efficiency of the process by facilitating the solubilization of copper. Another aspect of the invention resides in the advantages of maintaining solubilized copper in amounts between 10 grams per liter and the solubility limit in the reduction circuit.

Abstract: Ammonium hydroxide is added to a mixture of high-temperature, high-pressure geothermal steam and brine to raise the pH of the brine to between 6.0 and 7.0 and precipitate out a gelatinous sludge of aluminum and iron hydroxides. The hydroxide sludge is suspended in the brine and sweeps out enough dissolved silica so that the temperature and pressure of the brine can be reduced with little, if any, formation of silica scale. Various metals and ammonium hydroxide may then be recovered from the brine, the ammonium hydroxide being recycled in the process.

Abstract: An ammonium carbonate leach solution containing dissolved nickel and/or cobalt values is sprayed into a flash chamber to flash a portion of the ammonia therefrom, resulting in the production of a fine precipitate of nickel and/or cobalt carbonate. The solution is introduced into a stripping tower wherein remaining ammonia is stripped therefrom to precipitate further nickel and/or cobalt carbonate on the previously precipitated carbonate, which function as nuclei to reduce deposition in the column.

Abstract: A continuous process is provided which has the primary purpose of removing NH.sub.3, H.sub.2 S, HCN, and (CN).sub.2 from the subject gas mixtures and the secondary purpose of producing (NH.sub.4).sub.2 SO.sub.4 and iron oxide for industrial uses. The gas mixture which contains tar and other condensible vapors, NH.sub.3, H.sub.2 S, HCN, and (CN).sub.2 together with small volumes of gas from the ammonia still of the system, and gas from a system H.sub.2 SO.sub.4 plant, is contacted in a single three-stage reaction chamber in the presence, if need be, of a tar solvent, additional NH.sub.3, and the reagent Fe(OH).sub.2, which itself is a product of a concurrent reaction between NH.sub.3 and FeSO.sub.4. The unpurified gas mixture's condensible vapors are largely prevented from condensing by maintaining a steady, elevated temperature, while the mixture is essentially freed of HCN, (CN).sub.2, NH.sub.3, and H.sub.2 S in the reactor before the gas mixture passes through a primary gas cooler.

Abstract: The present invention relates to an improved process for removing iron ions from an aqueous acid solution with a minimum removal of copper ions contained therein comprising the steps of combining an organic quaternary salt with the aqueous acid solution in an amount of at least about 0.01% by weight of said solution, adjusting the pH of the solution to a value in the range of from about 2.0 to about 2.5 so that iron ions contained in the solution are hydrolyzed and precipitated and then separating the precipitate from the solution.

Abstract: A hydrometallurgical process for separating iron and nickel contained in iron and nickel-bearing sulphide materials, comprising selective leaching of iron with respect to nickel with hydrochloric or other mineral acid to provide a leach solution and leached solids. The nickel contained in the leach solution is separated from the dissolved iron as nickel sulphide by precipitation with hydrogen sulphide in the presence of an iron-bearing substance in which the iron is present in a form selected from the group comprising oxides, hydroxides and combinations thereof.

Abstract: The invention is a process for winning nickel by treating an aqueous ammonium salt solution of nickel salts with a carbon monoxide-containing gas under reducing conditions to produce nickel carbonyl and subsequently recovering nickel therefrom. Optionally, the production of nickel carbonyl can be catalyzed, for example, by cyanide. Also, an essentially water-immiscible solvent for nickel carbonyl can optionally be employed. The aqueous ammoniacal solution is typically an aqueous ammoniacal ammonium chloride, carbonate, sulfate, hydroxide, or mixture thereof. The valuable metals associated with nickel, e.g., copper, cobalt, iron, and precious metals, are also separated and recovered by this process. The general nature of the process allows a wide variety of primary and secondary sources of nickel to be utilized by combining this process with a number of known ore-treatment steps.

Abstract: A method for recovering a heavy metal oxidation catalyst used in a liquid-phase oxidation process for producing terephthalic acid from the residue of the reaction mother liquor by stirring the residue together with water in the presence of molecular oxygen and a sulfur compound, subjecting the extracted mixture to a solid-liquid separation to separate the solid impurities, adding the aqueous solution containing the oxidation catalyst to an alkali metal or ammonium carbonate or an aqueous solution of an alkali metal or ammonium carbonate while maintaining the temperature of the system at about 26.degree.C to 70.degree.C, and recovering the heavy metal catalyst as a carbonate precipitate having high purity and good filterability and washability.

Abstract: In conventional processes for separating metals by selective precipitation, the precipitate is frequently in an amorphous form, eg a slime, which is difficult to filter, wash and handle generally. In the present process mixed solutions and/or sols of the metals are mixed with a suitable soluble organic polymer to form a viscous mixture. The latter is formed into discrete entities, e.g. drops, which are contacted with a reagent which converts each drop to a gelled entity containing at least one of the metals as a precipitate.In one form of the process, the same chemical reagent also serves to dissolve the other metal present in the initial drops. The metals are then easily separated by separating the gelled drops from the reagent. In another form, the reagent includes two different chemical reagents which contact the drop simultaneously, one to precipitate one metal in the gelled drops and the other to dissolve the other metal.

Abstract: A method is provided for separating nickel and cobalt from a cobalt-nickel precipitate, the cobalt being in the cobaltic state. The method comprises dissolving the precipitate in an ammonium sulfate solution containing NH.sub.3, acidifying the solution to a pH of about 1.5 to 3.0 and then cooling the solution to produce a nickel-ammonium sulfate precipitate highly enriched in nickel. The precipitate is separated from the solution and the solution passed through an ion exchange column selective to the removal of nickel, the solution remaining containing said cobalt substantially free of nickel, the cobalt solution being then sent to cobalt recovery.

Abstract: A method is provided for enriching nickel in a nickel-cobalt solution to a nickel-to-cobalt ratio of over 2000:1, wherein an aliquot portion of the solution is removed, the nickel precipitated from said aliquot portion in the nickelous state, the nickelous precipitate thereafter oxidized to the nickelic state and the oxidized nickel precipitate then mixed with the remaining nickel-cobalt solution to oxidize the cobalt therein to the cobaltic state which precipitates from the solution, thereby highly enriching the solution in nickel.