Abstract: Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.

Abstract: The present disclosure is directed, in certain embodiments, to processes for recovering metals from polymetallic nodules. The processes may include one or both of (i) a weak acid wash of the polymetallic nodule material and (ii) nano-filtration and/or limestone neutralization of recycled manganese-rich stream to remove magnesium from process streams to improve the recovery of target metals, including manganese. The processes may include cobalt and/or nickel solvent extraction to improve metal(s) recovery.

Abstract: Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.

Abstract: Processes are provided for treating mineralized silicates by selective leaching of Ni and Co values carried out in concert with sequestration of gaseous CO2 as mineral carbonates. These processes may be applied to extract Ni and Co values from disparate laterite ores.

Abstract: The invention provides for the orchestrated treatment of disparate fractions of a shale deposit to recover vanadium values, with distinct steps of beneficiation that together provide a combined vanadium-enriched concentrate amenable to subsequent combined steps of hydrometallurgical vanadium extraction.

Abstract: Processes are provided for the selective recovery of lithium from brines using aqueous redox reactions, involving lithium extraction into a particulate ferric phosphate solid in the form of an iron (III) heterosite, in the presence of a reducing agent capable of reducing ionic lithium, at a controlled lithium extraction pH. Lithium elution involves exposing the loaded lithium ferrous phosphate solids, in the form of lithium iron (II) triphylite, to an oxidizing agent capable of mediating the oxidation of the sequestered atomic lithium. This is carried out at a controlled acidic lithium elution pH. Conditions in the lithium extraction and elution steps are provided so that a concentrated liquid lithium eluate is provided to subsequent steps of impurity removal and lithium carbonate precipitation.

Abstract: Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.

Abstract: Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.

Abstract: The invention provides for the orchestrated treatment of disparate fractions of a shale deposit to recover vanadium values, with distinct steps of beneficiation that together provide a combined vanadium-enriched concentrate amenable to subsequent combined steps of hydrometallurgical vanadium extraction.

Abstract: Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.

Abstract: Processes are provided for the selective recovery of lithium from brines using aqueous redox reactions, involving lithium extraction into a particulate ferric phosphate solid in the form of an iron (III) heterosite, in the presence of a reducing agent capable of reducing ionic lithium, at a controlled lithium extraction pH. Lithium elution involves exposing the loaded lithium ferrous phosphate solids, in the form of lithium iron (II) triphylite, to an oxidizing agent capable of mediating the oxidation of the sequestered atomic lithium. This is carried out at a controlled acidic lithium elution pH. Conditions in the lithium extraction and elution steps are provided so that a concentrated liquid lithium eluate is provided to subsequent steps of impurity removal and lithium carbonate precipitation.

Abstract: Hydrometallurgical processes are provided for the recovery of metal values, including cesium, from epithermal mineral deposits, including pharmacosiderite-containing ores. Aspects of the process involve the preferential formation of a cesium alum, and preparation of cesium hydroxide from the cesium alum.

Abstract: The invention provides hydrometallurgical processes for the recovery of rare earth values from ore, using simple crushing without beneficiation to produce an enriched and purified mixed rare earth concentrate. Ore is crushed to a relatively coarse particle size, and then treated with relatively small amounts of acid, at a relatively modest elevated temperature, to render the rare earth elements extractable in a subsequent water leach.

Abstract: Hydrometallurgical processes are provided for the recovery of metal values, including cesium, from epithermal mineral deposits, including pharmacosiderite-containing ores. Aspects of the process involve the preferential formation of a cesium alum, and preparation of cesium hydroxide from the cesium alum.

Abstract: The invention provides hydrometallurgical processes for the recovery of rare earth values from ore, using simple crushing without beneficiation to produce an enriched and purified mixed rare earth concentrate. Ore is crushed to a relatively coarse particle size, and then treated with relatively small amounts of acid, at a relatively modest elevated temperature, to render the rare earth elements extractable in a subsequent water leach.

Abstract: In an example of a method for recovering lead from a lead material including lead sulfide, methane sulfonic acid is selected as a leaching acid for the lead material. The lead material is exposed to a solution including the methane sulfonic acid and i) ferric methane sulfonate or ii) oxygen, which leaches lead from the lead sulfide in the lead material, and generates a liquid leachate including a lead-methane sulfonate salt. The liquid leachate is purified, and lead is recovered from the purified liquid leachate using electrolysis.

Abstract: In an example of a method for recovering lead from a mixed oxidized lead material, methane sulfonic acid is selected as a leaching acid for the mixed oxidized lead material. The mixed oxidized lead material is exposed to a solution including the methane sulfonic acid, which leaches lead from any of a lead oxide or a lead carbonate in the mixed oxidized lead material, and generates a liquid leachate including a lead-methane sulfonate salt. The liquid leachate is purified, and lead is recovered from the purified liquid leachate using electrolysis.

Abstract: In an example of a method for recovering lead from a lead material including lead sulfide, methane sulfonic acid is selected as a leaching acid for the lead material. The lead material is exposed to a solution including the methane sulfonic acid and i) ferric methane sulfonate or ii) oxygen, which leaches lead from the lead sulfide in the lead material, and generates a liquid leachate including a lead-methane sulfonate salt. The liquid leachate is purified, and lead is recovered from the purified liquid leachate using electrolysis.

Abstract: In an example of a method for recovering lead from a mixed oxidized lead material, methane sulfonic acid is selected as a leaching acid for the mixed oxidized lead material. The mixed oxidized lead material is exposed to a solution including the methane sulfonic acid, which leaches lead from any of a lead oxide or a lead carbonate in the mixed oxidized lead material, and generates a liquid leachate including a lead-methane sulfonate salt. The liquid leachate is purified, and lead is recovered from the purified liquid leachate using electrolysis.

Abstract: The present invention relates to methods for recovering precious metals including silver and gold, rare metals including indium and gallium, base metals including copper, lead and zinc or a combination of precious, rare and base metals from complex oxide ores, sulfide ores or oxide and sulphide ores using an acid chloride oxidizing leach.