Abstract: A novel class of extractants and a method of using the extractants in the hydrometallurgical recovery of nickel and cobalt metal. The extractants comprise a water immiscible organic solvent system containing solubilized mercaptide anion. In an important embodiment of the invention, the mercaptide anions are generated by adding compounds containing both a thiol group and an amine group such as aminoethanethiols or amides of thioglycolic acids to water immiscible organic solvents, preferably of polar character. These systems generate the required mercaptide anions by undergoing an internal acid dissociation.The extractants are used by being contacted with cobalt, nickel, or cobalt and nickel pregnant aqueous solutions. On mixing, the cobalt and/or nickel values are taken up by the organic as cobalt and nickel mercaptides. These may then be stripped of cobalt and nickel by treatment with an aqueous alkaline solution and carbon monoxide.

Abstract: A process for preparing hypochlorous acid in a sweep reactor is described in which gaseous chlorine is passed rapidly across the surface of an agitated aqueous solution of alkali metal hydroxide at a reduced temperature. The resulting gaseous product mixture of hypochlorous acid, chlorine monoxide, and unreacted chlorine is conveyed from the reactor to a suitable scrubber to produce an aqueous hypochlorous acid solution.The aqueous reaction product of the sweep reactor is a suspension of alkali metal chloride in alkali metal hypochlorite, which is withdrawn and filtered to separate the solid. The clarified aqueous solution of alkali metal hypochlorite is reacted with the aqueous hypochlorous acid solution from the scrubber, chlorine and lime to form an aqueous slurry of calcium hypochlorite. This slurry may be granulated by the spray graining technique, for example, to produce strong rounded granules of calcium hypochlorite.

Abstract: A process for preparing hypochlorous acid is described in which gaseous chlorine is reacted with an aqueous solution of alkali metal hydroxide in a finely divided mist form at an elevated temperature sufficient to prevent condensation of the gaseous product. Gaseous hypochlorous acid product is immediately separated from the resulting solid alkali metal chloride as it is formed and is then scrubbed with water to form an aqueous hypochlorous acid solution. This solution may be reacted with lime to produce calcium hypochlorite.

Abstract: This invention provides a two-stage leaching procedure for manganese nodules for obtaining directly from a second leaching stage a substantially pure stream of copper free of other metal values, the other metal values, including manganese, nickel and cobalt, having been previously extracted in an earlier leaching stage. Both leaching operations are carried out utilizing an ammoniacal aqueous solution on a reduced manganese nodule.

Abstract: Particulate waste comprising hydrolyzable metal chlorides, typically chlorinated byproducts from the chlorination of titaniferous material, is treated in an oxidizing atmosphere at elevated temperature for depleting it of chlorine and for subsequent recovery of values.

Abstract: The efficiency of a low total acid normality chlorine dioxide producing process in which a chlorate, a chloride and sulphuric acid are fed to a reaction medium in a single chambered generator-evaporator-crystallizer vessel is increased by the use of small quantities of methanol.

Abstract: An energy efficient process is disclosed for the hydrometallurgical oxidation of sulfidic minerals containing copper, silver, nickel, cobalt, molybdenum, or zinc values. A high density slurry, e.g., 67% by weight solids, is prepared from a particulate sulfide mineral and water. Nitrogen dioxide and preferably also oxygen are added to the slurry to oxidize the sulfidic minerals and to produce solubilized cations and nitric oxide. The nitric oxide is oxidized to nitrogen dioxide, thereby regenerating the principal oxidant. If oxygen is added to the slurry along with NO.sub.2, then the regeneration occurs in-situ.

Abstract: Fluorite ores and concentrates commonly contain sulphur as an impurity usually as the sulphate. This sulphur can be largely removed by heating the ore or a concentrate under reducing conditions.In the preferred process the ore or a concentrate is pelletized with carbon, heated to a temperature up to 900.degree. C. in a neutral atmosphere which is conveniently nitrogen or carbon dioxide or a mixture thereof.

Abstract: A process for extracting metal values from aqueous solutions of metal salts which comprises the steps of contacting the aqueous solution with a solution in a water-immiscible organic solvent of one or more o-hydroxyaryloximes containing at least 3 aliphatic or alicyclic carbon atoms and which are strong metal extractants and one or more alkylphenols optionally containing one chlorine atom or one cyano group, separating from the aqueous phase the solvent phase containing metal in the form of a complex with the o-hydroxyaryloxime contacting the solvent phase with an aqueous mineral acid, and separating the solvent phase from the aqueous phase containing metal in the form of a salt with the mineral acid.

Abstract: The invention relates to the recovery of chlorine values from iron chloride by-produced from the chlorination of a titaniferous material containing more than 5% by weight iron oxide, and particularly from the carbo-chlorination of ilmenite, which, for example, can be the first stage in the so-called chloride route to form titanium dioxide pigment.The iron chloride which may be ferric chloride or ferrous chloride is subjected to a combination of reduction and oxidation reactions. In the reduction reaction, ferric chloride is dechlorinated to ferrous chloride by a reducing agent suitable for producing a chloride compound for recycle to the chlorination process or for sale and in the oxidation reaction ferrous chloride is oxidized to ferric oxide and ferric chloride, the ferric chloride being recycled to the reduction reaction.

Abstract: The present invention provides a novel process for the preferential chlorination of alumina over silica in the carbo-chlorination of kaolinitic ores to produce aluminum chloride. The process comprises introducing small amounts of alkali metal compounds with oxyanions into the carbo-chlorination process. Preferred embodiments are directed to particular compounds of alkali metals with oxyanions selected from the group consisting of carbonates, sulfates, hydroxides, oxides, phosphates, and the like. The present invention results in significantly reduced energy, manufacturing, and equipment costs and thus represents a breakthrough in the utilization of domestic ores such as kaolinitic clay for the production of aluminum chloride or alumina through oxidation of the aluminum chloride.

Abstract: Nickel, cobalt and manganese are recovered from deep sea nodules by leaching with sulfurous acid. In addition, selective extraction of nickel and cobalt from copper is achieved by suitable adjustment of process variables such as leaching time and volume and concentration of acid.

Abstract: This invention provides a two-stage leaching procedure for manganese nodules for obtaining directly in one leaching stage the metal values other than manganese in one ammoniacal aqueous solution. The manganese nodules are reduced and then leached initially utilizing a solution of an ammonium salt, e.g., ammonium sulfate, to selectively leach out the manganese value, followed by a second stage leaching with an ammoniacal solution, to leach out the nickel, cobalt and copper values. The nickel, cobalt and copper values can then be individually separated from the second leach solution by liquid ion exchange extraction.

Abstract: Gypsum and magnetite which are both coarse and of good quality can simultaneously be produced by introducing calcium carbonate into an aqueous solution containing ferrous sulfate while an oxidizing gas is blown, and then carrying out a neutralizing and oxidizing operation at a pH of 5-6 and a temperature of 60-80.degree. C, and can be separately recovered by magnetic separation.

Abstract: A method is disclosed to produce chlorine dioxide from sodium chlorate by reacting the chlorate with HCl. The method comprises forming in a reaction vessel an aqueous reaction medium containing at least about 5.5 moles per liter of the sodium chlorate, sufficient HCl to provide an acid normality of at least about 0.002, and sufficient sodium chloride to saturate the reaction medium; boiling the reaction medium at a temperature of up to about 100.degree. C; and withdrawing a mixture containing chlorine dioxide gas, chlorine gas and water vapor from the reaction vessel.

Abstract: Titanium dioxide of improved properties for use as a pigment is obtained by a process in which a non-concentrated acid solution containing not more than 200 grams of TiO.sub.2 per liter of solution is partially hydrolyzed and filtered; and additional acid solution slowly added with heating to hydrolyze the remaining TiO.sub.2 and give a product which, on calcining has a color index of about 1500.

Abstract: Sulfidic minerals containing metal values such as copper, silver, nickel, cobalt, molybdenum, zinc, iron, or mixtures thereof are oxidized with nitrogen dioxide to enable the metal values to be solubilized in an aqueous acidic leach liquor. In practicing the invention, the minerals are added to an aqueous acidic leach liquor and a nitrogen dioxide containing gas is sparged through the slurry to oxidize the metal values. During the reaction, the nitrogen dioxide is reduced to nitric oxide. The nitric oxide is oxidized to nitrogen dioxide by oxygen, either in-situ, or in a separate off-gas oxidizer.

Abstract: Disclosed is a process for the recovery of nickel from nickel-containing wastes, which comprises the steps of slurrying the waste with a nickel brine solution; reacting the slurry by addition of an oxidizing agent solution, followed by anhydrous hydrogen chloride to obtain a nickel chloride containing reaction mixture; and, filtering the reaction mix to obtain the nickel chloride solution.

Abstract: Titanium dioxide component is removed from a mineral containing titanium dioxide component which is difficult to be separated by the conventional electrostatic separation.In the electrostatic separation from the mineral containing titanium dioxide component, the mineral is pretreated by a heat-treatment in an atmosphere of reducing, neutral or inert gas or a mixture thereof so as to change the electrostatic property of titanium dioxide and separating by an electrostatic separation.

Abstract: Undigested matte particles in autoclave leach residues containing iron oxide are separated from iron oxide by subjecting an aqueous slurry thereof to flotation without the use of a flotation reagent by bubbling air therethrough to form a froth containing said undigested matte particles which is recycled for further leaching and provide an iron oxide-containing tails which is removed and discarded.