Abstract: A method of treating sulphidic mattes containing from 5% to 60% iron; from 15% to 40% sulphur together with soluble non-ferrous metals such as copper, cobalt, nickel and zinc and also optionally insoluble non-ferrous metals which term includes platinum group metals gold and silver by a leaching process to effect substantial separation of the non-ferrous metals from iron as well as from insoluble residue material. The matte is contacted in a finely subdivided form with sulphate in acid medium at a temperature of from 70.degree. C. to 120.degree. C. and an oxygen partial pressure of from 50kPa to 1,000kPa. The quantity of sulphate present is at least the stoichiometric amount required for dissolving the soluble non-ferrous metals present but is limited to ensure that a substantial proportion of iron which dissolves simultaneously with the soluble non-ferrous metals precipitates out as it is replaced by dissolving non-ferrous metals.

Abstract: The process for recovering recyclable sulphur from a strongly colored solution obtained from the production of sulphur dyestuffs containing alkali metal sulfides, alkali metal polysulfides, sulphur dyestuffs or mixtures thereof comprising(a) mixing said solution at an alkaline pH with a decolorizing amount of an iron or zinc compound which is a hydroxide or the salt of an inorganic acid whereby a precipitate is formed,(b) separating the precipitate to isolate a decolorized solution, and either(c) precipitating elemental sulphur from the decolorized solution by adding sulphur dioxide or alkali metal thiosulfate under acidic conditions, and(d) separating the precipitated elemental sulphur, or(e) recycling the decolorized solution for use in the manufacture of sulphur dyestuffs.

Abstract: A method is provided for reconditioning a hydrogen sulfide removal system, such as a Stretford process system in which elemental sulfur is formed, after the system has become contaminated with sulfur-feeding bacteria to an extent that operation thereof is substantially impaired. The method includes adding a bactericide to the washing solution employed in the system to destroy the bacteria and adding a non-ionic surfactant to the solution to remove dead bacteria from the surfaces of particulate sulfur formed in the system so that the particles can agglomerate in the intended manner to enable sulfur removal from the solution.

Abstract: A method of treating pyrite bearing polymetallic material comprises heating the material in an atmosphere of reducing gases at a temperature of 450.degree. to 500.degree. C. for a period of 30 to 60 min.Gases such as hydrogen, or products of conversion of natural gas or mazut can be used to provide the reducing atmosphere.The roasted copper-containing material is cooled at a rate of 2 to 4 deg. per min and is then subjected to magnetic separation.The operation of magnetic separation is carried out in two stages with the intensity of the magnetic field ranging from 1000 to 2000 oersted, whereafter copper sulphides are removed from the roast, with a magnetic field intensity ranging from 4500 to 6000 oersted.

Abstract: A method for the removal of carbon or carbon compounds from a waste stream generated in an unsupported slurry catalyst process utilized for the hydroconversion of heavy hydrocarbonaceous black oil which stream comprises vanadium sulfide, nickel sulfide and carbon or carbon compounds is disclosed. The carbon or carbon compound is removed by contacting the waste stream with sulfur dioxide at oxidizing conditions to yield a solid residue which contains metal sulfides.

Abstract: Flue gas having a content of sulfur dioxide is passed upwardly through a scrubbing tower against a descending flow of recycled aqueous sodium aluminate-sodium hydroxide liquor. The sulfur dioxide in the gas is converted to sodium and aluminum sulfates and sulfites and the liquor removes any fly ash present in the gas. Underflow is continuously discharged from the tower and is sent to an evaporator for removal of excess water. Make-up solutions of sodium sulfate and aluminum sulfate are added, as necessary. Carbonaceous reducing agent is added to the discharge from the evaporator. The mixture is continuously fed into a reducing furnace where the sulfates and sulfites are reduced to sulfides. The product of the furnace (molten sodium and aluminum sulfides) is charged into a continuous hydrolyzer. Hydrogen sulfide is evolved and collected, and, if desired, its sulfur content is converted to elementary sulfur. The underflow from the hydrolyzer is filtered.

Abstract: Removing hydrogen sulfide from geothermal steam condensate is described whereby the hydrogen sulfide that is present in the condensate from a geothermal steam plant is oxidized with a peroxygen compound such as hydrogen peroxide in the presence of catalytic quantities of sodium vanadate under neutral to alkaline conditions.

Abstract: A process for removing hydrogen sulfide from geothermal steam comprising adding free oxygen to the steam and contacting the steam with an oxidation catalyst at a pressure of at least 30 psig and a temperature not greater than the saturation temperature of the steam. The catalyst may comprise activated carbon, a refractory inorganic oxide or a metal phthalocyanine and is wetted with an aqueous solution of thiosulfates, sulfates or polysulfides. The hydrogen sulfide is converted and steam of reduced hydrogen sulfide content is obtained.

Abstract: A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a regenerable washing solution containing solubilized vanadium thiocyanate ions, a carboxylate complexing agent and one or more water-soluble quinones capable of solubilizing tetravalent vanadium. The molar ratio of vanadium to quinone(s) in the washing solution is selected to substantially reduce or eliminate the formation of contaminant sulfate salts. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the washing solution, is separated from the regenerated solution.

Abstract: H.sub.2 S is removed from a stream of gas such as coal gas at a relatively elevated temperature (300.degree.-400.degree. F.) in a process which employs sulfates or hydroxides of nickel, iron, or zinc as sulfur absorbents. The absorbents are converted to metal sulfides during the absorption process and are regenerated by aeration. Acids produced during sulfur absorption and absorbent regeneration steps are neutralized through the addition of a base. In a preferred embodiment ammonia is also removed and elemental sulfur is produced during the process.

Abstract: This invention relates to a process for the removal of sulfur compounds from a gas stream. More specifically, this invention relates to an improvement in the iron oxide method of sulfur removal from a gas stream through the use of hydrogen peroxide.

Abstract: The process for recovering recyclable elemental sulfur from a strongly colored solution containing alkali metal sulfides, alkali metal polysulfides, or mixtures thereof comprising(a) mixing said solution at an alkaline pH with a decolorizing amount of an iron or zinc compound which is a hydroxide or the salt of an inorganic acid whereby a precipitate is formed,(b) separating the precipitate to isolate a decolorized solution,(c) precipitating elemental sulfur from the decolorized solution by adding sulfur dioxide or alkali metal thiosulfate under acidic conditions, and(d) separating the precipitated elemental sulfur.

Abstract: At least one of sulfur dioxide and a gaseous hydrosulfide is contacted with at least one of a sulfur-containing salt and a gaseous basic nitrogen compound to produce a solid, sulfur-containing composition.

Abstract: A process is provided for the production of hydrogen and sulphur from a gas containing hydrogen sulphide. Such a process comprises passing the gas through a cracking zone at a temperature of from about 850.degree. C. to 1600.degree. C., cooling the cracked gas to a temperature of from about 110.degree. C. to 150.degree. C., and separating the condensed elemental sulphur. The uncracked hydrogen sulphide is separated and returned to the cracking zone; the remaining gas is withdrawn as hydrogen-rich gas.

Abstract: An improved method for the oxidation of water-soluble inorganic sulfide ions in aqueous systems is disclosed. The method uses a soluble metallic ion catalyst in the presence of an oxidizing agent. The improvement comprises adding to the system a water-soluble anionically-charged polymer having a molecular weight of from 1,000-100,000. Additionally, certain organic phosphonate materials can be used in combination with the polymer.By the use of the polymer or polymer-phosphonate treatment the efficiency of the metallic ion catalyst and the sulfide oxidation step is improved.

Abstract: A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a substantially quinone-free aqueous washing solution containing, inter alia, solubilized vanadium, thiocyanate ions, and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the washing solution, is separated from the regenerated solution.

Abstract: A process for the removal of hydrogen sulphide from gases or liquid hydrocarbons, comprising contacting the gas or liquid hydrocarbon with an aqueous alkaline solution, preferably having a pH value of 8 to 10, comprising(a) an anthraquinone disulphonic acid or a water-soluble sulphonamide thereof(b) a compound of a metal which can exist in at least two valency states and(c) a sequestering agent comprising a compound of formula I: ##STR1## wherein R is an aliphatic residue containing from 1 to 12 carbon atoms and which is optionally substituted or interrupted by one or more hydroxy, or carboxyl groups; a carbonyl group, a phenyl group; or an aralkyl group containing 7 to 10 carbon atoms; and n is an integer of from 1 to 4; as well as salts, especially alkali metal and ammonium salts, and esters of compounds of formula I.

Abstract: A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a regenerable washing solution capable of absorbing the hydrogen sulfide and converting the hydrogen sulfide to hydrophobic elemental sulfur particles. After oxidative regeneration of the washing solution, the sulfur particles are transferred to a nonaqueous carrier liquid to thereby form a substantially nonaqueous sulfur slurry which is then heated to melt the sulfur and form a dense liquid sulfur product which separates by gravity from the carrier liquid.

Abstract: A method for producing ammonia and hydrogen sulfide in a molar ratio (NH.sub.3 /H.sub.2 S) from about 2.8 to about 3.7 from an aqueous ammonium thiosulfate solution by a method consisting essentially of: (a) contacting the aqueous ammonium thiosulfate solution with hydrogen sulfide at a temperature from about 260.degree. to about 360.degree. F. (125.degree. to 182.degree. C.) at a pressure greater than 100 psig to react at least about 70 percent of the thiosulfate to produce an aqueous solution containing ammonium polysulfide; and (b) heating the resulting aqueous ammonium polysulfide solution to produce ammonia and hydrogen sulfide in a molar ratio (NH.sub.3 /H.sub.2 S) from about 2.8 to about 3.7 and sulfur.

Abstract: Hydrated alkali metal sulfides used to remove sulfur from fossil fuels to form alkali metal polysulfides which are recycled to alkali metal sulfides and elemental sulfur by thermal or thermal reduced pressure decomposition of the alkali metal polysulfides or by conversion of the hydrolysis products entirely by H.sub.2 S.

Abstract: A process of reacting in the liquid phase a hexacoordinated ruthenium(II) complex with oxygen in the presence of a source of hydrogen ions under conditions forming hydrogen peroxide and the corresponding hexacoordinated ruthenium(III) complex and reacting the hexacoordinated ruthenium(III) complex with hydrogen sulfide to form elemental sulfur and regenerate the hexacoordinated ruthenium(II) complex, the hexacoordinated ruthenium(III) complex having a reduction potential of not more than +0.68. Five or six of the ligands of the ruthenium complexes are non-labile in both valence states.

Abstract: Flue gas having a content of sulfur dioxide is passed upwardly through a scrubbing tower against a descending flow of recycled aqueous sodium aluminate-sodium hydroxide liquor. The sulfur dioxide in the gas is converted to sodium and aluminum sulfates and sulfites and the liquor removes any fly ash present in the gas. Underflow is continuously discharged from the tower and is sent to an evaporator for removal of excess water. Make-up solutions of sodium hydroxide, sodium sulfate and aluminum sulfate are added, as necessary. Carbonaceous reducing agent is added to the discharge from the evaporator. The mixture is continuously fed into a reducing furnace where the sulfates and sulfites are reduced to sulfides. The product of the furnace (molten sodium and aluminum sulfides) is charged into a continuous hydrolyzer. Hydrogen sulfide is evolved and collected, and, if desired, its sulfur content is converted to elementary sulfur. The underflow from the hydrolyzer is filtered.

Abstract: In methods for combusting carbonaceous sulfur-containing fuels in a fluidized bed wherein the fluidized bed contains at least one calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate and calcium bicarbonate to absorb sulfur oxides formed during the combustion of the carbonaceous fuel thereby producing calcium sulfoxy compounds having the formula CaSO.sub.x wherein x is 3 or 4, an improvement comprising (a) withdrawing a stream of fluidized bed solids containing said calcium sulfoxy compounds and mixing the fluidized bed solids and said calcium sulfoxy compounds with water to produce a slurry; (b) reacting the CaSO.sub.x compounds with NH.sub.3, H.sub.2 O and CO.sub.2 to produce water-soluble ammonium sulfoxy compounds such as NH.sub.4 (HSO.sub.x) where x is 3 or 4 and CaCO.sub.3 ; and (c) separating the ammonium sulfoxy compounds from the fluidized bed solids and CaCO.sub.3.

Abstract: A process for thermal activation of chalcopyrite-pyrite ore concentrates for activation of iron values in both chalcopyrite and pyrite constituents whereby said iron values can be selectively removed in a subsequent acid leach. Controlled oxidizing conditions are maintained in an oxidizing heating zone for removal of up to about 90% of total sulfur to be removed for conversion of pyrite and chalcopyrite to their acid-leachable forms, measured by a preferable oxidation of 10 to 15% of iron in the concentrate to ferromagnetic oxides, whereby remaining total sulfur to be removed is removed in a reducing zone with the assistance of a low H.sub.2 S/(H.sub.2 +H.sub.2 S) ratio by scavenging of H.sub.2 S by said oxides.

Abstract: The process of the invention is for the separate recovery of elemental sulfur and residual sulfides and metal salt solution from reaction slurries obtained from leaching of metal sulfides in ores and concentrates.

Abstract: A process for treating a pyrite concentrate containing silver, copper and zinc to recover the metals contained therein is disclosed. The process includes the partial roasting of the concentrate to open the pyrite matrix to solution penetration followed by hydrometallurgical steps, including ferric sulphate leaching, reduction leaching, solid-liquid separation and metal extraction steps, to recover the copper and zinc separately and silver in concentrated form.

Abstract: A process for treating a pyrite concentrate containing silver, copper, lead and zinc to recover the metals contained therein is disclosed. The process includes the partial roasting of the concentrate to open the pyrite matrix to solution penetration followed by various hydrometallurgical steps, including oxidation and reduction leaching, solid-liquid separation and metal extraction steps, to recover the copper and silver together, and the lead and zinc separately.

Abstract: A method for converting calcium sulfoxy compounds selected from the group consisting of CaSO.sub.x and Ca(HSO.sub.x).sub.2 where x is 3 or 4, into calcium carbonate by a method consisting essentially of: (a) converting the Ca(HSO.sub.x).sub.2 compounds into CaSO.sub.x compounds by reacting the CA(HSO.sub.x).sub.2 compounds with CaCO.sub.3 in the presence of water; (b) reacting the CaSO.sub.x compounds with NH.sub.3 and CO.sub.2 in the presence of water to produce NH.sub.4 HSO.sub.x and CaCO.sub.3 ; (c) separating the NH.sub.4 HSO.sub.x and CaCO.sub.3 ; (d) reacting the NH.sub.4 HSO.sub.x with H.sub.2 S to produce ammonium polysulfide (NH.sub.4).sub.2 S.sub..omega. wherein .omega. is from 1 to about 4; (e) decomposing the ammonium polysulfide to produce NH.sub.3, H.sub.2 S, elemental sulfur and water; and (f) recovering the elemental sulfur from the NH.sub.3, H.sub.2 S and water.

Abstract: Non-ferrous metal sulfides are converted to recover metals therefrom in a high speed rotary converter, wherein an oxygen-containing gas is used for said conversion, with sulfur trioxide added to the converter along with the oxygen-containing gas to assist in control of temperatures of the charge during conversion, the sulfur trioxide being reduced to sulfur dioxide within the converter and exhausted therefrom.

Abstract: The invention concerns catalysts for treating residual gases, containing hydrogen and carbon derivatives of sulphur, by the Claus reaction. These catalysts have a specific area of at least 80 m.sup.2 /g and essentially comprise active alumina and a titanium compound. They enable carbon compounds of sulphur to be destroyed and the Claus reaction proper to be obtained with good yields.

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: A method is disclosed for scrubbing SO.sub.2 and NO.sub.x containing gases with iron sulfide. The reaction proceeds only to the formation of FeS.sub.2 and FeSO.sub.4 without significant formation of sulfur or iron oxide. The reaction products are subsequently regenerated to FeS by heating and can be recycled for further scrubbing operations; elemental sulfur is recovered as a by-product.

Abstract: A reactant gas is mixed intimately with a liquid and/or particulate solution in a pressurized container and agitated with high energy. Mixing occurs initially by spraying the liquid and gas together to form an emulsion with great surface contact between the reactants, and the emulsion mix is improved and maintained by agitating in the container. The container is carried on oscillatable supports and is driven by an imbalance drive for vertical oscillation in any of several configurations. Loose mixing balls or bodies are optionally carried in the container to increase the agitation and to grind solid particles carried into the solution. The grinding bodies also source protective reaction-deposited layers from the solid particles to speed the reaction. Pressure and temperature of the process is readily controlled.

Abstract: An effluent alkali salt solution obtained in the desulfurization of a hydrogen sulfide-containing gas by washing with an alkali wash solution is subjected to a two stage precipitation treatment at different temperatures to recover valuable components such as a vanadium compound, chelating agent, ADA, and active alkali salts while removing inactive salts such as sulfate and thiosulfate.

Abstract: Chromates are removed from aqueous alkali metal chlorate solutions by either of two processes. In the first process, a water-soluble sulfide is added to react with the chromate, and then a ferrous salt is added. The soluble sulfate is converted to elemental sulfur and the chromate is converted to an insoluble trivalent Cr-containing material which is removed from solution. In the second process an "iron mud" is prepared by reacting a ferrous salt with sodium hydroxide and added so as to precipitate insoluble trivalent chromium-containing material.

Abstract: A continuous process is disclosed for removing sulfur dioxide from stack gases or other gaseous effluents without prior gas cleaning or dust removal and for converting the sulfur values to industrially useable elemental sulfur. The uncleaned gaseous effluent is scrubbed using a buffered absorbent to absorb the SO.sub.2 and remove particulate material, and the undissolved particulate material is removed from the scrubbing liquor as by filtration. The scrubbing liquor is then contacted with sulfide ion to form elemental sulfur while regenerating the absorbent in the liquor. Most of the liquor is separated from the precipitated sulfur and solid impurities, and the remaining material is heated to permit gravity separation of molten sulfur, scrubbing liquor and impurities. The separated scrubbing liquor is recycled for the scrubbing steps.The process is particularly advantageous when employing a sulfide ion source, such as sodium bisulfide or the like, to precipitate elemental sulfur.

Abstract: Process and apparatus for removing sulfur dioxide from gases such as stack gases. The gases are scrubbed with an alkali metal compound in an aqueous solution to form alkali metal sulfite/sulfate salts which are then reacted with barium sulfide to precipitate barium sulfite/sulfate and form alkali metal sulfide/bisulfide in solution. The alkali metal sulfide/bisulfide is oxidized to form elemental sulfur and regenerated wash liquid; and the barium sulfite/sulfate is reduced by roasting to form the barium sulfide required. In a preferable embodiment, coal is used as both the reductant and fuel in the roasting of the barium sulfite/sulfate and the stack gases from the roasting are scrubbed along with the primary stack gases. As an optional step a portion of the alkali metal sulfite salts may be oxidized to sulfate prior to reaction with barium sulfide.

Abstract: A process for producing a fuel gas and sulfur from a hydrocarbon fuel wherein a fuel oil containing sulfur is at least partially combusted in a fluidized bed of sorbent material which produces a substantially sulfur free fuel gas and a sulfided sorbent. The sulfided sorbent is passed to a second fluidized bed which regenerates the sulfided sorbent and produces a sulfur dioxide containing gas. The latter gas is contacted with granular coal in the presence of steam to reduce the sulfur dioxide to elemental sulfur.

Abstract: A process for removing hydrogen sulfide and/or mercaptans from hydrogen sulfide and/or mercaptans-containing gases using aqueous iodine slurry and/or solution to recover elemental sulfur as one product and to generate hydriodic acid which is dehydrated, pressurized, and decomposed into iodine for recycling and into hydrogen for recovering as another product.

Abstract: Elementary sulfur is obtained from sulfur-containing materials which release sulfur oxides (SO.sub.x) in the presence of oxygen by fluidizing such materials in a bed with an oxygen-containing gas (e.g., air), and passing the resulting SO.sub.x -containing gases through a bed (preferably fluidized) of carbonaceous or carbon-containing solids (such as coke or coal) at an elevated temperature to reduce SO.sub.x to elemental sulfur, the bottom of the bed of carbonaceous or carbon-containing solids being at about the level of the top of the bed of sulfur-containing materials.

Abstract: Sulfur and hydrogen are produced from hydrogen sulfide according to the present invention by bringing hydrogen sulfide into contact, at a temperature exceeding the boiling point of sulfur, with at least one member selected from the group consisting of the sulfides of molybdenum, tungsten and ruthenium to give rise to a gaseous mixture consisting of hydrogen sulfide, hydrogen and sulfur, cooling the produced mixture to separate therefrom the sulfur component in the condensed form and leave behind a gaseous mixture wherein the hydrogen component makes up the majority of the total weight thereof and subsequently removing hydrogen sulfide from this mixture by means of condensation or absorption.

Abstract: The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149.degree. C (300.degree. F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.

Abstract: A SO.sub.2 -containing gas is contacted with an ammonia solution, the resulting ammonium sulfite solution is vaporized to SO.sub.2 and NH.sub.3 , SO.sub.2 is partially reduced to H.sub.2 S and the resulting gas containing both SO.sub.2 and H.sub.2 S is first contacted with a catalyst to produce sulfur and then made free of sulfur by solvent washing; recovered NH.sub.3 is used to re-constitute the ammonia solution.

Abstract: A process for treating a hydrogen sulfide-containing feed gas, deficient in thiocyanate ion precursors, to convert the hydrogen sulfide to elemental sulfur in which said gas is contacted with an aqueous alkaline washing solution containing a water-soluble metal vanadate, and a water-soluble anthraquinone disulfonate to yield an effluent gas of reduced sulfur content. Thiocyanate ion precursors are added to the solution to reduce the chemical consumption of the anthraquinone disulfonate. The solution is thereafter regenerated by contact with an oxygen-containing gas; elemental sulfur is recovered from the solution; and the regenerated solution is recycled to the gas-contacting step.

Abstract: The invention provides a cyclic process for recovering copper from sulfide ores containing copper and iron which comprises reacting the sulfide ore with sulfur dioxide gas at a temperature of at least about 500.degree. C. to form elemental sulfur, removing the elemental sulfur, reacting the residual solids with concentrated sulfuric acid at a temperature of about 180.degree. to 500.degree. C. to form copper sulfate and sulfur dioxide gas, recycling the sulfur dioxide gas for reaction with additional ore, roasting the remaining solids at a temperature of about 400.degree. C. to 900.degree. C., leaching the roasted solids with an aqueous solution to solubilize the copper sulfate and recovering copper from the solubilized copper sulfate. In another embodiment of the invention, the roasting step is eliminated by removing magnetite from the solids remaining after removal of the elemental sulfur.

Abstract: This invention provides a method for treating manganese oxide ores in an aqueous medium, with hydrogen halide or sulfuric acid, and a hydrogen sulfide or a metal sulfide, e.g. an ore. A leach liquor containing the desirable metal halides is then separated from the solid, insoluble residue. Any iron value in either the manganese oxide ore or in any metal sulfide ore present is not dissolved or is converted to an insoluble iron oxide. Elemental sulfur is also obtained.The metal values in the leach liquor are recovered by crystallization of the manganese halide and liquid ion exchange extraction of the other metal values present.

Abstract: A chemical process for treating metal sulfide materials, such as copper sulfide concentrates, to produce water-soluble metal chlorides and preclude the production of undesirable sulfur oxides. Such a metal sulfide material is contacted with an effective amount of a chlorinating reagent solution at a temperature below the boiling point of the reagent solution. The reaction proceeds until the metal sulfides are converted into metal chlorides and elemental sulfur is formed. The chlorinating reagent solution contains a chlorinating agent having a labile chlorine atom capable of reacting with the metal values to form metal chlorides, and at least one liquid hydrocarbon solvent which is capable of solubilizing both the chlorinating agent and the elemental sulfur produced during the reaction. The metal chloride product, which is insoluble in the reagent solution, is recovered from such solution by conventional means, e.g. by filtration, for conversion into the metal or metals.

Abstract: A method of treating solid waste material containing minor amounts of water soluble chromium compounds with a reductant, particularly sulfide ions, to convert the soluble chromium to an insoluble state, and produce a solid waste from which substantially no chromium can be leached by water, as by exposure to rain.

Abstract: A commercially feasible method is provided for controlling depositions of solid sulfur within plant equipment utilized in absorptive-regenerative processes for the removal of H.sub.2 S from sour gas streams which eliminates costly shutdowns and manual cleaning of the plant equipment and permits removal of solid sulfur therefrom in conjunction with that produced during the regular process itself. The method comprises adding ammonia to such H.sub.2 S removal systems during running thereof in order to solubilize any solid sulfur and remove the same with the sulfur produced by circulating alkali absorption solution employed. Ammonia may be added to either the sour gas stream or directly to the absorption solution, and moreover can be added intermittently to remove preexisting sulfur deposits or on a semi-continuous basis as needed to substantially prevent undesirable sulfur buildup. The present method finds application in connection with known desulfurization processes such as the Stretford, Ferrox and Takahax.

Abstract: A process is disclosed for the production of sulfur which comprises the oxidation of a sulfide solution in the presence of a catalyst comprising a metal phthalocyanine compound to produce sulfur and a polysulfide effluent, decomposition of the polysulfide effluent with steam at a temperature of from about 115.degree. to about 125.degree.C. and a pressure of 10 psig, to about 20 psig. to produce a vaporous phase effluent containing water, hydrogen sulfide and ammonia, the oxidation of at least a portion of the vaporous effluent with an oxygen-containing gas in the presence of a catalyst comprising a metal phthalocyanine compound dispersed on a solid support, said catalyst being in contact with a liquid phase comprising a thiosulfate-containing compound, at a temperature of from about 115.degree. to about 125.degree.C. and a pressure of from about 10 psig. to about 20 psig. to produce steam, sulfur and a thiosulfate compound and the recovery of the resultant sulfur.