Abstract: An improved liquid-liquid extraction process for separating metals from each other in which an aqueous solution containing metals is mixed with an organic solution containing an extraction agent that releases hydrogen ions. A mixture of aqueous dispersed phase and an organic continuous phase is formed and the pH of the aqueous dispersed phase is controlled by the addition of a neutralizing agent to the mixture of the aqueous dispersed phase and the organic continuous phase on the basis of pH measurements made with pH electrodes immersed in the mixture of the phases. These direct measurements permit accurate adaptation of the rate of addition of the neutralizing agent to the rate at which hydrogen ions are being released so that the pH of the aqueous dispersed phase is kept substantially constant. The phases are separated from each other after transfer of metal ions from the aqueous to the organic phase, and the separated metal values are recovered.

Abstract: Phase disengagement between aqueous copper sulfate solutions and organic phases containing a liquid ionic change reagent is greatly facilitated when the dispersed medium from the mixture stage is contacted counter-currently to the direction of phase separation with a small amount of the respective separated phase having uniform appropriate droplet size.

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: Organic acids are added to ammoniacal leach liquors containing base metals such as copper, nickel and cobalt. Ammonia and carbon dioxide are then stripped from the leach liquor by heating the leach liquor sufficiently to drive off the ammonia and carbon dioxide. The resulting loss of ammonia and carbon dioxide causes the pH of the leach liquor to drop and enables the metal values to load onto the organic acid. Metal values are selectively stripped from the loaded organic acid.

Abstract: Copper values are extracted from aqueous solution by dihydroxy azoarenes dissolved in a water immiscible organic solvent.

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: The recovery of non-ferrous transition metals such as copper and nickel from acidic hydrometallurgical leach liquors with a 2-picolylamine chelate exchange resin is improved by the in situ reduction of Fe.sup.+.sup.3 present in the leach liquor with a water soluble reducing agent during the resin loading cycle. The chelate resin functions not only as a selective sorbent for the desired metal values, but also as a catalyst for the in situ reduction of Fe.sup.+.sup.3 to Fe.sup.+.sup.2. A suitable reducing agent such as SO.sub.2 or HCHO is fed into the chelate resin column with the leach liquor. When the loading cycle is completed, regeneration with sulfuric acid gives an enriched eluent with a high non-ferrous metal:Fe ratio. For example, using SO.sub.2 with a copper leach liquor feed, subsequent regeneration at about 70.degree. C gives better than 90 percent recovery of the copper as a highly enriched copper sulfate solution with a Cu:Fe ratio of about 10,000.

Abstract: A process is described for recovering metals which are present in aqueous solution as complex metal ammine ions having an ammonia co-ordination of at least two. According to the process, the complex metal ammine bearing solution is contacted with a cationic ion exchange resin in the ammonium form to effect loading of the complex metal ammine ions from the solution onto the resin. The loaded resin is then stripped by contacting it with a controlled volume of aqueous ammonium salt stripping solution having an ammonium ion concentration of at least two molar. The free ammonia and ammonium salt concentrations in the stripping solution are controlled such that the controlled volume of stripping solution is effective to substantially completely strip the free ammonia and metal values from the resin.

Abstract: A process for separating zinc and copper values from an aqueous solution of copper and zinc salts having a pH of between about 0.5 and 6 is provided comprising:A. contacting said aqueous solution with the copper salt of di-(2-ethylhexyl) phosphoric acid to form a zinc-containing organic phase and a copper-containing aqueous phase;B. separating said zinc-containing organic phase from said copper-containing aqueous phase; andC. stripping said organic phase to form a solution of a zinc salt and di-(2-ethylhexyl) phosphoric acid.

Abstract: A hydrochloric acid leach solution is subjected to a first cycle of extraction by an organic solvent, solvent washing and stripping so that the stripping liquor contains iron, zinc, cadmium and gallium while the liquor constituted by the first raffinate at the outlet of the extraction unit mainly contains nickel, cobalt and copper. In a second extraction cycle, the stripping liquor contains copper while the second raffinate mainly contains cobalt and nickel. In a third extraction cycle, the stripping liquor contains cobalt while the third raffinate mainly contains nickel.

Abstract: Ammoniacal leach solutions containing nickel and copper (and possibly other base metal values) are treated by first extracting copper leaving nickel in the raffinate. The nickel in the raffinate is subsequently extracted with an organic extractant. The nickel loaded organic extractant is subsequently stripped with a highly concentrated ammonium salt solution to yield a strip concentrate from which nickel or nickel oxide is recoverable without electrolytic treatment. To prevent build up of copper in the nickel extraction circuit, part or all of the organic from the nickel strip circuit is recycled back to the copper extraction circuit where copper on the organic is eventually stripped. In the copper extraction circuit, the nickel on the recycled organic is replaced by copper from the aqueous, preventing build up of nickel on the organic leaving the copper extraction circuit.

Abstract: A method of separating gold from palladium or at least one of gold and palladium from solutions containing the chloride complexes of at least the relevant ones of these metals together with other platinum group metals and wherein base metals may be present in the solution said method comprising contacting the solution for a sufficient length of time to result in extracting of substantially all the required gold and for palladium values present therein, with a suitable quantity of a water insoluble non-volatile solvent extractant in an organic phase and having functional groups of the formula R.sup.1 --S--R wherein R.sup.1 and R may be the same or different and have a carbon atom thereof joined directly to the sulphur atom; R.sup.1 and R being chosen so that neither of them have active functional groups capable of acting as ion exchangers or complexing groups and thereafter separating the two phases and recovering the extracted gold and palladium.

Abstract: This invention provides a process for separating the halide of cobalt, and optionally nickel, from a pregnant aqueous solution, the aqueous solution also containing a manganese halide. The process comprises initially extracting the cobalt halide and a portion of any manganese halide which is present into an organic extract. The nickel halide is then separately extracted from the solution. The manganese halide is preliminarily preferentially stripped from the organic extract containing cobalt and manganese utilizing an aqueous solution comprising halide ions. The cobalt halide in the extract can then be stripped into an aqueous solution together with the remaining manganese to form a strip solution. The manganese is then preferentially extracted from the strip solution, leaving a manganese-free, substantially pure cobalt solution. Any nickel can be selectively extracted from the manganese remaining in the pregnant solution.

Abstract: This invention relates to the purification of industrial effluents containing cyanide ions, and cyanide precursors like acetone-cyanohydrin. More particularly, the invention relates to the purification of such effluents by utilizing a complexing compound followed by treatment with an anion exchange resin and optionally cation exchange resin to remove the cyanide complexes. The cyanide values are recovered from the resin by acid regeneration.

Abstract: A process in which copper, nickel, cobalt and molybdenum are recovered by direct leaching of comminuted raw manganese nodules with an aqueous ammoniacal leach solution containing cuprous ions. During the process cuprous ions reduce the nodules, are consumed, and are oxidized to cupric ions. The cuprous ions are regenerated by reducing the cupric ions with a reducing gas.

Abstract: A process for the recovery of metal values, principally zinc and copper, from an aqueous acidic purge stream in a hydrometallurgical process by contacting the stream containing the iron, copper and zinc sulfates, along with trace amounts of other metallic sulfates with calcium oxide to bring the pH in the range 3.0-4.0, thence with sufficient ammonia to form the soluble tetrammine sulfates of copper and zinc, then separating the copper from the zinc, e.g. by hydroxy oxime-solvent extraction and thereafter recovering the zinc as zinc oxide by converting the zinc tetrammine sulfate to the hydroxide and removing ammonia from the complex.

Abstract: An improvement in the process of extracting metal from aqueous acidic solution using a quaternary ammonium thiocyanate extractant wherein a special amount of thiocyanate ion is introduced into the aqueous solution prior to or contemporaneously with the extraction. Results achieved are better extractions with little or no additional loss of thiocyanate ion in the aqueous raffinate.

Abstract: In the electrolytic refining of silver that contains a significant amount of copper, the electrolyte is withdrawn from the refining cell, preferably continuously but alternatively at intervals, and is contacted with an immiscible liquid phase containing a selective complexing agent for cupric ions. The liquid phase carries away at least some copper from the electrolyte without the need to remove the silver first. The treated electrolyte, depleted of copper, is re-usable and is normally returned to the cell. In a continuous-withdrawal system a steady copper level can be maintained in the electrolyte. The complexing-agent phase can be regenerated and copper recovered from it.

Abstract: A method of leaching copper values from copper dross obtained from pyro-metallurgical lead bullion by contacting finely-divided particles of the copper dross with an aqueous ammoniacal solution, preferably a solution of ammonium carbonate and ammonium hydroxide, to dissolve copper from the dross. The leaching will usually be carried out in a gas containing free oxygen and the leaching solution may advantageously contain sulphate ions in addition to carbonate ions.

Abstract: Metal can be recovered from metal-containing waste by means of liquid extraction processes. The waste is leached with sulphuric acid. The resulting metal sulphate solution is contacted with an organic solution of a reagent, so as to extract iron and zinc to the organic solution. The organic solution is washed with sulphuric acid in two steps, viz. with weaker acid in the first step, so as to transfer zinc to the washing solution, and with stronger acid in the second step, so as to transfer iron to the washing solution. Zinc and iron have now been separated, and are recovered from the washing solutions in known ways, for example by crystallization. If the waste contains other metals, in addition to iron and zinc, additional selective liquid extraction processes are added, before or after the iron-zinc-extraction.

Abstract: Uranium values are obtained from phosphate rock by acidifying phosphate rock containing uranium values and at least one other heavy metal with a mineral acid so as to obtain a crude acid, solvent extracting the crude acid with an organic solvent so as to separate a raffinate from a relatively pure, wet process phosphoric acid and treating said raffinate with a base so as to raise the pH to 1-2 whereby uranium hydroxide or phosphate and other heavy metal hydroxides or phosphates are coprecipitated. The uranium content of the coprecipitate after drying is at least as high as 0.3% which is comparable to that of uranium ores of the highest quality.

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: In a process for the production of adipic acid by nitric acid oxidation of cyclohexanol and/or cyclohexanone wherein copper and vanadium values are recovered by ion exchange means, the improvement which comprises utilizing the off-gas from the nitric acid oxidation to treat the solution being passed to the ion exchange zone.

Abstract: A system utilizing membrane extraction is provided to recover metal values. The system may be used to separate metal ions from an aqueous solution through the membrane by an organic liquid containing a chelating agent. This invention also contemplates the recovery of metal values from an organic phase, containing the metal complexed with a chelating agent, by an aqueous phase using membrane extraction. In the former case, the metal ion is passed through the membrane from the aqueous phase to the organic phase where it forms a complex with a chelating agent present in the organic phase. In the latter case the metal is extracted from the organic phase into the aqueous phase through the membrane. In both cases a chelating exchange reaction is involved at the interface between the membrane and one of the two phases. This hydro-metallurgical process employs membranes with metal ion diffusivity in the range of about 10.sup..sup.-5 to about 10.sup..sup.-8 cm.sup.2 /sec.

Abstract: O-Nitrosophenols adapted for the liquid-liquid extraction of metals, e.g., copper, from aqueous solutions and a nitrosation process for the preparation of the phenols.

Abstract: Ocean floor nodules are treated with aqueous hydrogen halide to produce a pregnant leach solution which is subjected to selective solvent extraction to isolate metal values contained in the ore.

Abstract: Method for treating basic salts to preferentially extract copper without using a base to maintain the required pH. The liberation of unreacted hydrogen ions during the ion exchange reaction is eliminated by partially dissolving the basic salt mixture with an amount of acid that is equivalent to the non-copper content of the basic mixture. An amount of organic ion exchange extractant is selected so that the exchangeable hydrogen ion on the extractant is equivalent to or in excess of the amount of copper in the metal bearing liquor.

Abstract: A process in which copper, nickel, cobalt and molybdenum are recovered by leaching comminuted raw manganese nodules with an aqueous ammoniacal leach solution containing cuprous ions. An improvement is disclosed in which the metal values are extracted directly from the leach slurry with an organic extractant. To accomplish such extraction the amount by weight of solids in the slurry is maintained at less than 20 percent, the pH of the slurry is lowered to 9.5, the volumes of slurry and organic are maintained at a ratio so that the organic is the continuous phase and the organic and slurry are mixed with gentle agitation.

Abstract: Quinoline-2-carboxylic acids having in the 4-position a halogen atom or an optionally substituted hydrocarbyl group attached through an oxygen atom, optionally substituted by a hydrocarbyl group in the 3 position and optionally substituted in any of the 5, 6, 7 and 8 positions by halogen atoms, nitro or cyano groups, or optionally substituted hydrocarbyl groups each attained directly or through an oxygen atom, and containing in the substituents in the 3, 4, 5, 6, 7 and 8 positions a total of at least 3 carbon atoms form complexes with metals, especially copper. These complexes may be extracted by organic solvents from aqueous solutions of metal salts treated with the quinoline-2-carboxylic acids.

Abstract: This invention provides a process for separating metal values from an anhydrous mixture of metal halides in a fluid state, i.e. vapor or liquid; the separation is made by contacting a fluid mixture containing a halide of at least one less-noble metal selected from the group consisting of iron and manganese, and a halide of at least one more-noble metal selected from the group consisting of copper, cobalt and nickel, with an elemental metal. This procedure is especially effective in the refining of ocean floor nodule ores.

Abstract: Naphthenohydroxamic acid is prepared by reaction at 25.degree.C to 30.degree.C, equimolar quantities ofA. an ester of naphthenic acid,B. hydroxylamine dissolved in an alcohol/water/alkali metal sulfate slurry wherein the water content of the slurry is insufficient to hydrolyze the ester during conversion to naphthenohydroxamic acid, andC. an alkali metal hydroxide dissolved in alcohol.Naphthenohydroxamic acid is useful as a chelating agent in hydrometallurgy to recover metal values from dilute solution.

Abstract: A process is disclosed which is directed to recovering gold and/or silver values from activated carbon, wherein gold and/or silver has been adsorbed thereon. The process comprises eluting the activated carbon with water soluble alcohols or ketones either alone or with aqueous solutions thereof and a strong base may be added to further facilitate elution.

Abstract: A compound having the general formula ##SPC1##In which R.sup.1 , R.sup.2, R.sup.3 and R.sup.4 may be the same or different and represent hydrogen, a straight or branched chain alkyl radical having 1 to 20 carbon atoms, an aralkyl radical having 7 to 20 carbon atoms which may be substituted by one or more alkyl groups having 1 to 4 carbon atoms, or may be of the type: ##SPC2##Wherein R.sup.5 and R.sup.6 are each a hydrogen atom or a methyl group, and each R represents the others of R.sup.1, R.sup.2, R.sup.3 and R.sup.

Abstract: This invention provides a process for selectively removing metal values from ocean floor nodule ore by a two-stage procedure. In the first stage, the ore is leached with an aqueous solution of sulfuric acid or a hydrogen halide to preferentially remove nickel and copper. In the second stage, the ore is leached with a reducing agent to preferentially remove cobalt and manganese. The two leach solutions can then be further treated to separate the individual metal values, e.g., by liquid ion exchange procedures.