Abstract: A process for treating zinc sulphide materials wherein the sub-divided material is firstly leached, under pressure at less than 119.degree. C., with a sulphate leach solution low in sulphuric acid and having a high iron content together with zinc and impurities in a manner causing iron to precipitate and subsequently leaching the residue and redissolving the iron precipitate with spent electrolyte containing regenerated sulphuric acid resulting from the treatment of the leach liquor obtained from the first leach step and wherein the leach solution from the subsequent leach step constitutes the starting leach solution for the first leach step. The second leach step is carried out in two phases; a first leach phase conducted at elevated pressure and elevated temperature (less than 119.degree. C.) in the presence of oxygen and a second phase at atmospheric pressure and without the supply of free oxygen to the leach solution.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.

Abstract: A process for precipitating iron as a jarosite from a sulphate solution containing ferric iron, free acid and valuable non-ferrous metals, characterized by cooling the solution; partially neutralizing the free acidity, and then clarifying the solution; heating the clarified solution to a temperature not exceeding the boiling point at atmospheric pressure, in the presence of at least one ion selected from the group consisting of sodium, potassium and ammonium ions, and in the presence of recycled jarosite, and without the addition of any further neutralizing agent, so that substantially all of the ferric iron is precipitated as a jarosite; and separating precipitated jarosite from the solution; thereby producing a jarosite contaminated with only minor amounts of non-ferrous metals, and a solution which may be further processed by established procedures for the recovery of dissolved valuable non-ferrous metals therefrom. The invention also contemplates a dilution step, and recycle of jarosite.

Abstract: A method for the recovery of zinc from zinc oxide ores and/or roasted zinc sulfide or concentrates, wherein the zinc ore source is leached under substantially neutral conditions to produce a residue having a relatively high content of undissolved zinc, the residue is dried, and then suspended in a hot gas stream preferably in a smelting cyclone under reducing conditions to thereby volatilize off zinc and other readily volatile metals as their oxides. The oxide mixture thus produced is recovered and then subjected to a neutral leaching which selectively removes zinc values as well as other metal values.

Abstract: The invention provides a process for extracting zinc from a sulphur- and zinc-containing ore which involves (a) leaching the sulphur ore or concentrate with an aqueous solution of cupric chloride, which can be regenerated by means of a regenerating agent and air; (b) subjecting the solution thus obtained to liquid-liquid extraction by means of an organic phase, preferably containing a solvent, comprising an acid organophosphorus compound; and (c) recovering the zinc contained in the said organic phase after the said extraction, preferably by elution. If justified by the composition of the ore, the following optional recovery steps may then be performed:(1) if lead is present, recovery of lead by cementation (i.e., precipitation) or by crystallization of lead dichloride followed by cementation of the crystallizate;(2) if copper is present, recovery of copper by cementation or by liquid-liquid extraction; and(3) if precious metals, e.g.

Abstract: A process for the recovery of copper and zinc values from copper and zinc containing sulphidic ore includes subjecting ground ore to a flotation operation. An initial copper concentrate is floated in a first flotation step, and the initial copper concentrate is fed to a second flotation step to float a relatively zinc free copper concentrate. Remaining ore from the first flotation step is fed to a third flotation step to float an initial zinc concentrate, and remaining ore from the third flotation step is fed to a fourth flotation step to float a copper and zinc containing material. An intermediate concentrate containing from about 5 to about 25% copper and from about 2 to about 25% zinc, with a total of at least about 12% copper and zinc, is produced by selecting at least the remaining ore from the second flotation step, and a zinc concentrate containing at least about 20% zinc is produced by at least selecting a portion of the initial zinc concentrate.

Abstract: In a hydrometallurgical treatment for eliminating one or more metal impurities from a solution containing a metal to be extracted and said metal impurities, a silicate is added to the solution forming in situ dissolved silicic acid and precipitating the metal impurities at a pH of between 1.5 and 4.5 to form a solid silicate residue.

Abstract: A process for treating zinc sulphide materials wherein the sub-divided material is firstly leached, at less than 119.degree. C., with a sulphate leach solution, low in sulphuric acid and having a high iron content together with zinc and impurities in a manner causing iron to precipitate and subsequently leaching the residue and re-dissolving the iron precipitate with spent electrolyte containing regenerated sulphuric acid resulting from the treatment of the leach liquor obtained from the first leach step and wherein the leach solution from the subsequent leach step constitutes the starting leach solution for the first leach step.

Abstract: A process for the production of a sulphidic copper concentrate from a complex sulphidic concentrate containing as its main constituents copper, iron and at least one non-ferrous metal selected from the group consisting of zinc, lead, nickel and cobalt, comprising mixing the complex sulphidic concentrate with a copper-containing predominantly chloridic solution thereby to form a suspension, and treating the suspension thus obtained at elevated temperature and pressure at a pH-value of below 3, thereby to form a sulphidic copper concentrate, thereby the non-ferrous metals being extracted from the concentrate without formation of significant amount of acid. Precious metals may also be present. Advantageously the ratio by weight of the complex concentrate added to the copper-containing predominantly chloridic solution to the copper content of the solution is such that the predominantly chloridic solution after being at least partly freed from copper by an exchange reaction has a potential at 60.degree. C.

Abstract: A process for treating sulfide ores to reduce the sulfur content or recover the metal content therefrom comprises the use of enzymatic action to solubilize the sulfur and metal content.A nutrient, such as a saccharide, is used along with yeast spores which feed on the sugar and produce enzymes which act on sulfur in the sulfide ore to cause the sulfur to go into solution and to dissolve those metals which are soluble in strongly acidic solution. Sulfuric acid can be formed from the sulfide ores or from free sulfur by reaction with water, with evolution of hydrogen sulfide gas. Oxidation of at least a portion of the hydrogen sulfide can be achieved to regenerate sulfuric acid.

Abstract: The present invention relates to a process for treating residues from a primary leaching of ferriferous zinc ores by sulphuric acid, with a view to recover a leadbearing by-product, such process comprising a secondary leaching of said residues, by sulphuric acid, within several countercurrent stages, at a temperature comprised between 85.degree. and 100.degree. C., the solid residues of the successive stages being circulated from the first to the last stage, the residue of this last stage being the said lead bearing by-product, whereas the various solutions separated from the second to the last stage are each recycled within the leaching operation of the respectively foregoing stage, and the dual zinc and iron sulphates solution, as separated from the first stage, being the principal product of the treatment.

Abstract: Certain sulfonylthiosemicarbazides, metal complexes thereof and solutions of said compounds in essentially water-immiscible, liquid hydrocarbon solvents are disclosed. The sulfonylthiosemicarbazides have the general structural formula: ##STR1## wherein R and R.sup.1 are as defined in the specification and claims hereof. Particular metal values are recovered from their aqueous solutions by using sulfonylthiosemicarbazides dissolved in essentially water-immiscible, liquid hydrocarbon solvents. The extraction process involves contacting the metal value containing aqueous solution with the solution of the sulfonylthiosemicarbazide in essentially water-immiscible, liquid hydrocarbon solvent and stripping the metal from the loaded organic phase.

Abstract: Particulate matter collected by an environmental air quality control device may be in part toxic in nature and thus not readily disposable. By separating the toxic portion of the particulate matter from a nontoxic portion, disposal of nontoxic portion may be more easily accomplished. This separation may be readily effected where the toxic portion is soluble and the nontoxic portion is insoluble, thus allowing the toxic soluble portion to be formed into a solution with a dissolving liquid. The nontoxic insoluble portion then may be filtered from the toxic solution, rinsed, dried and disposed of accordingly.

Abstract: Process and apparatus for the electrowinning of metals from sulphide ores wherein a sulphide ore is initially leached in a water soluble sulphide solution, alkali is then added, and the resulting solution is electrolyzed so as to deposit metal at the cathode and obtain water soluble sulphide as a by-product. The process is particularly suitable for obtaining antimony from stibnite.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.

Abstract: A process is disclosed for the separation and recovery of zinc from material in which it is contained as a sulfide. Zinc sulfide containing material is chlorinated in an aqueous medium in the presence of elemental chlorine and ferric/ferrous ions to form a solution containing zinc chloride, iron chloride and elemental sulfur. The solution is treated with elemental chlorine and alkali to precipitate the iron (e.g. at about pH 3 to 4). Zinc chloride is recovered from the solution by means known to those skilled in the art such as by electrolysis. The precipitated iron is recycled for use as a secondary chlorinating solution to treat the solid residue of the initial chlorination leaching step.

Abstract: Process for extraction and separation of metals utilizing the advantages of liquid-liquid extraction with cation exchangers without requiring the equivalent addition of alkali. The process is based on a combination of leaching the metal-containing raw materials with an organic acid (cation exchanger) and a subsequent use of the formed metal cationic complex in a liquid-liquid extraction process. In the said extraction process, the organic solution of metal complexes is used to recover and separate metal ions from an aqueous solution of metal salts.

Abstract: A process for precipitating iron as a jarosite from a sulphate solution containing ferric iron, free acid and valuable non-ferrous metals, characterized by cooling the solution; partially neutralizing the free acidity, and then clarifying the solution; heating the clarified solution to a temperature not exceeding the boiling point at atmospheric pressure, in the presence of at least one ion selected from the group consisting of sodium, potassium and ammonium ions, and in the presence of recycled jarosite, and without the addition of any further neutralizing agent, so that substantially all of the ferric iron is precipitated as a jarosite; and separating precipitated jarosite from the solution; thereby producing a jarosite contaminated with only minor amounts of non-ferrous metals, and a solution which may be further processed by established procedures for the recovery of dissolved valuable non-ferrous metals therefrom. The invention also contemplates a dilution step, and recycle of jarosite.

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: Sulfidic minerals containing metal values such as copper, silver, nickel, cobalt, molybdenum, zinc, iron, or mixtures thereof are leached in two stages. In the second stage, preleached minerals are oxidized with nitrogen dioxide to enable the metal values to be solubilized in the aqueous acidic leach liquor in that stage. During the reaction, the nitrogen dioxide is reduced to nitric oxide. The nitric oxide is oxidized to nitrogen dioxide by oxygen. The acidic metal bearing liquor from the second stage flows to a first stage where it preleaches fresh minerals. The metal bearing liquor is delivered from the first stage to metal recovery while preleached minerals are delivered to the second stage.

Abstract: Process for purifying an iron containing zinc sulfate solution which comprises precipitating iron from said solution as a slurry in at least one of the following forms at a pH which is maintained lower than 4: basic sulfate, jarosite or goethite; filtering said slurry on a planar horizontal filter and forming a cake on said planar filter; washing the cake directly on the planar filter with water supplied onto the cake without forming a newslurry with washing water and thus freeing the cake from water soluble zinc and copper compounds promptly before hydrolysis thereof insolubilizes said compounds as basic sulfates, whereby the solid residue in the cake does not contain substantially more insoluble zinc content than it contained in the slurry being fed to the filtration.

Abstract: A method for treating nonferrous metal hydroxide sludge waste to separate and recover the nonferrous metals therein wherein the waste is first mixed with an alkali hydroxide or carbonate, dried, and then roasted and the water-insoluble residue in the roasted material is treated with sulfuric acid to produce an acid-insoluble residue and a sulfuric acid solution containing copper, aluminum and chromium and thereafter, separating the copper from this solution by liquid-liquid extraction and thereafter, separating the aluminium, chromium, zinc and nickel from the remaining solution by separate liquid-liquid extraction steps.

Abstract: In the recovery of copper, nickel or zinc from sulfide ores by leaching with ammonium sulfate solution containing free ammonia in the presence of oxygen to form a leach solution containing dissolved copper, nickel or zinc ammonia sulfate complex, an alkaline metal hydroxide (preferably calcium hydroxide) is introduced into the leaching operation to precipitate the sulfate ion formed and to release ammonia combined therewith as ammonium ion.

Abstract: The process of leaching manganiferous ocean nodule ores with HCl whereby the manganese and other metals present, such as iron, zinc, cobalt, nickel, copper, and like are converted from oxides, silicates or other insoluble forms to water soluble chlorides, and are thereafter separated, purified, and the manganese recovered as MnO.sub.2 by oxidation with chlorine to provide a material suitable for use in metallurgical applications, may be improved by controlling the chlorine pressure and the pH of the leaching reaction in order to first leach out the metals other than manganese; as chloride, and thereafter recovering the manganese in the form of its silicate, aluminate, oxide, or the like.

Abstract: Mercury and caustic values are recovered from caustic sludges in a process which comprises intermixing the caustic sludge with a liquid under pressure or agitation to produce a caustic slurry which is separated into a caustic liquor, metallic mercury and a remaining sludge which is suitable for roasting in a retort to recover better than 99 percent of the mercury in the sludge.The process recovers valuable mercury and caustic materials and eliminates pollution of natural resources which was formerly caused when these sludges were disposed of in landfill operations. In addition, the process reduces potential hazards to personnel handling the caustic sludges and requires no addition of chemicals which produce undesirable by-products and add to the cost of the recovery process.

Abstract: A hydrometallurgical process for the treatment of a soluble silicate-bearing material for the recovery of its valuable metal content by leaching the silicate-bearing material at an elevated temperature with an aqueous solution of a mineral acid, precipitating silicic acid during the same stage in an easily settling and filtering form, the silicate-bearing material being added at such a rate that its concentration calculated as SiO.sub.2 corresponds to the simultaneously precipitating silicic acid quantity, and by finally separating the solid material from the valuable-metal-bearing solution.

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: 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: A process for the treatment of zinc calcine containing zinc oxides, zinc sulfates and zinc ferrites, which comprises neutral leaching, hot acid leaching, jarosite precipitation and recycling of the jarosite containing pulp whereby there is obtained increased zinc extractions, improved settling and filtering characteristics of the leach pulp, simplified operation and process control and increased ammonium removal.

Abstract: Zinc is recovered from a material containing zinc and iron. The material is leached with sulphuric acid to produce a final pH of 3-5.5. Zinc powder is added to the leaching solution to precipitate polluting metals. Zinc is now extracted with a solution of a dialkyl phosphoric acid in an organic solvent. Zinc is extracted from the organic solution with sulphuric acid. Zinc is recovered from the sulphuric acid solution as metal or as zinc sulphate.

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: Ores or mineral mixtures containing zinc sulphides and magnesium and/or calcium in the form of carbonates, oxides and/or hydroxides are leached with an aqueous sulphur dioxide bearing solution to selectively dissolve magnesium and/or calcium leaving the zinc sulphides in the undissolved residue in concentrated form. During the dissolution reaction, the pH is maintained within the range of about 1 to about 4 by the addition of sulphur dioxide to the leach solution at a rate at least sufficient to replace sulphur dioxide taken up in the dissolution of magnesium and/or calcium thereby promoting selective dissolution of the magnesium and calcium compounds and non-dissolution of the zinc sulphides.

Abstract: A process for extracting non-ferrous metal values from an oxide ore. The process comprises leaching the ore with a solution containing at least one alkali metal chloride or alkaline earth chloride salt in the presence of an oxygen-containing gas at a temperature and pressure sufficient to solubilize the non-ferrous metal values into the solution of the metal chloride salt.

Abstract: A process and a product formed thereby for the recovery of chromium values from aqueous solutions (e.g., waste liquors) comprises contacting an acidic solution containing sulfate ion and trivalent chromium ion with at least about 4 molar equivalents of MgO or Mg(OH).sub.2 per 3 molar equivalents of trivalent chromium in addition to the amount required to neutralize the free acid to a pH of about 4 to form an amorphous, dense solid, grainy, easily settleable, trivalent chromium-containing precipitate in an alkaline solution according to the equation: 3Cr.sub.2 (SO.sub.4) + 8 MgO .fwdarw.Cr.sub.2 (OH).sub.4 SO.sub.4 .multidot. 4Cr(OH).sub.3 .multidot. 4H.sub.2 O + 8 MgSO.sub.4. The trivalent chromium-containing product can be readily separated from the water and is a useful source of chromium for subsequent processing. The water remaining after separation of the precipitate contains less than 0.5 mg/l chromium.

Abstract: A process for treating a residue from the sulfuric acid leaching of roasted zinc blende, comprising(a) leaching the residue in a single stage with sulfuric acid and a metal sulfide supplied in a quantity sufficient for transforming the iron into divalent iron, the temperature being maintained between about 60.degree. C and the boiling point,(b) heating the mass to a temperature above the melting point of sulfur, separating a first fine-grained residue of low zinc and iron contents and high lead content, and separating a coarse-grained residue containing sulfur, compounds of iron and any excess metal sulfide from (a),(c) adjusting the pH of the residual solution to at most about 2, at a temperature between about 80.degree.

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: After separating brine from the slime and drying the same with solids therein, dried solids are subjected to roasting in an oxydizing temperature of 350.degree. to 400.degree. C, and then leaching the roasted material with predetermined acid and withdrawing sulfur oxides from waste gases generated during the roasting step.

Abstract: A process of leaching silicated zinc ores with sulfuric acid in which the ore is reacted at elevated temperature with at least a stoichiometric amount of sulfuric acid, treating products of the reaction with a predetermined quantity of hot water, filtering the zinc sulfate solution from precipitated silica, washing with a further predetermined quantity of hot water (the total amount of hot water used being determined so as to obtain the desired concentration of zinc in solution). The zinc is later recovered electrolytically. A 1 to 6N sulfuric acid solution may be used in which case a gelatinous mass is formed upon reaction and then it is evaporated at 100.degree. C of at least 60% of its water content. Alternatively the ore can be malaxated with about 20% stoichiometric excess concentrated sulfuric acid, and filtered at out at elevated temperature.

Abstract: The zinc-containing dust from an iron-making (blast) furnace or a steel-refining (e.g. converter) furnace is recovered and extracted with water saturated with carbon dioxide to solubilize the zinc. The zinc solubilized in the CO.sub.2 -saturated water is then precipitated by the elimination of carbon dioxide therefrom.

Abstract: A process for the re-utilization of the sulphate residues from the electrolytic treatment of zinc.The residues are digested hot with concentrated HCl in the presence of CaCl.sub.2. PbCl.sub.2 crystallizes on cooling. FeCl.sub.3 is extracted with TBP circulating in the direction of a series of columns and FeCl.sub.3 is extracted in a first column, washed in a second column and re-extracted a third column. The solution which issues is treated with NH.sub.3, resulting in precipitation of the majority of the hydroxides of the metals contained therein, which are subsequently separated, while Ag, Zn and Cu are complexed. Ag is precipitated with (NH.sub.4).sub.2 S.NH.sub.3 is recovered by means of lime. CaCl.sub.2 is re-cycled to the start of the process and Cu and Zn are leached together with the mineral.Application of the process to the recovery of the metals contained in the residues from the digestion of blends.

Abstract: Zinc values are leached or converted in a solution containing excess SO.sub.2 or HSO.sub.3.sup.- ions, selectively extracted from that solution into an organic phase containing organo acid phosphates and stripped from the organic phase for further processing.

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 process for recovery of zinc values contained in thermally activated iron containing copper and zinc sulfides in which said activated sulfides have been subjected to an acid leach in aqueous sulfuric acid to produce a solution of ferrous sulfate and a solids residue containing copper and zinc values. The solids residue containing copper and zinc values is reacted with an acidic copper sulfate solution to precipitate copper values as a simple copper sulfide with concurrent dissolution of iron and zinc values to form a solution of ferrous sulfate containing said dissolved zinc values and said solution of ferrous sulfate is separated from the simple copper sulfides and reacted with H.sub.2 S for precipitation of zinc values therefrom as zinc sulfide. Any nickel and cobalt values present in said activated sulfides is dissolved in said solution of ferrous sulfate and reacted with the H.sub.2 S at elevated temperature for selective precipitaton.

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: The method comprises the steps of crushing of the ore, neutralization by a mixture of water and sulphuric acid, introduction of a controlled quantity of sulphur dioxide gas at a pH value between 1.5 and 4 for promoting dissolution of nickel, copper and a desired quantity of manganese, leaching of the ore with sulphuric acid at a pH value between 1 and 3 for selectively dissolving the nickel and copper, separation of the solid and liquid phases, and separation of the metals contained in the liquid phase.

Abstract: Metal values are extracted from manganiferous ocean floor nodule ore by treating the ore with hydrochloric acid, thereby producing chlorine and a starting pulp containing a solution of the metal chlorides and a solid residue. The starting pulp is subjected to at least two subsequent acidifications with HCl, each acidification being followed by addition of fresh ore, thereby producing chlorine and a final pulp containing a concentrated solution of metal chlorides and a solid residue. The solid residue is separated from the concentrated solution and substantially all the metal values, except manganese and alkali and alkaline earth metals, are separated from the solution. The manganese is separated from the solution by treatment with chlorine, at least the major portion of which was produced in the preceding leaching steps, while maintaining the solution at a pH of between about 3 and 7 by addition of a neutralizing agent such as MgO or Mg(OH).sub.2 whereby the manganese is precipitated in the form of MnO.sub.

Abstract: This invention relates to a process for hydrometallurgical treatment of concentrates of sulphides of copper, nickel, cobalt, lead and iron and copper-containing mattes. A first embodiment of the process includes subjecting a finely ground slurry of a sulphide concentrate to an oxidation leach at elevated temperature and pressure in the presence of an oxygen-bearing gas to preferentially leach cobalt and nickel and to convert galena to lead sulphate. The reaction mixture is heated to a further elevated temperature, in the absence of oxygen, to convert a portion of chalcopyrite to insoluble simple copper sulphides and ferrous sulphate solution and to decompose complex insoluble ferric compounds. The resulting mixture is subjected to differential flotation whereby a lead concentrate and a copper concentrate are obtained.

Abstract: Copper, zinc and nickel are recovered from sulfide concentrates prepared from ores of one or more such metals by subjecting such concentrate to a leaching operation which comprises slurrying the concentrate in an aqueous solution containing ammonium sulfate and free ammonia and vigorously agitating the slurry at 50 to 80.degree. C. and below 10 psig. in the presence of free oxygen while vigorously recirculating said oxygen from above the surface of the slurry to a substantial depth below such surface. The resulting pregnant leach solution contains copper, zinc, and/or nickel in dissolved form complexed with ammonia and such solution is treated to recover the dissolved metal. The undissolved sulfidic residue from the leaching operation is subjected to a secondary flotation operation to produce a sulfide concentrate containing the metal values not dissolved in the leaching operation, and such concentrate is treated to recover such values, as by smelting or by releaching.

Abstract: An improvement in conventional processes for recovering metal values from sulfide ores containing lead, zinc and silver sulfides in which process the metal sulfides are converted to chlorides by chlorination followed by solubilization of the chlorides with a sodium chloride leach and subsequent recovery of the metals from their chlorides in accordance with a conventional flow sheet including crystallization, cementation, precipitation, fused salt electrolysis, etc., with chlorine being recovered for reuse by electrolysis of the sodium chloride leach solution substantially depleted of lead, silver and zinc, the improvement being a pollution-free process which comprises:1. recycling the sodium chloride solution depleted of a major percentage of lead and silver to the sodium chloride or brine leaching step; and2.

Abstract: Process for extraction and separation of metals utilizing the advantages of liquid-liquid extraction with cation exchangers without requiring the equivalent addition of alkali. The process is based on a combination of leaching the metal-containing raw materials with an organic acid (cation exchanger) and a subsequent use of the formed metal cationic complex in a liquid-liquid extraction process. In the said extraction process, the organic solution of metal complexes is used to recover and separate metal ions from an aqueous solution of metal salts.