A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196° C. to about 3000° C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

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.

An extractant which makes it possible to extract both light rare earths and heavy rare earths from an aqueous phosphoric acid solution, likely to be present in this solution, and which is characterised in that it comprises: a compound of formula (I) below: ##STR00001##
wherein R1 and R2, identical or different, are a hydrocarbon group, saturated or unsaturated, linear or branched, in C6 to C12; R3 is a hydrocarbon group, in C1 to C6, or a hydrocarbon group, saturated or unsaturated, monocyclic, in C3 to C8; R4 and R5, identical or different, are a hydrogen atom or a hydrocarbonate group, saturated or unsaturated, linear or branched, in C2 to C8; and a surfactant. Applications of this extractant include treatment of aqueous solutions from the leaching of natural phosphates by sulphuric acid and aqueous solutions from the leaching of urban minerals by phosphoric acid, in view of making profitable use of the rare earths present in these solutions.

The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

The invention relates to a hydrometallurgical process which makes it possible to selectively recover at least one “heavy” rare earth metal, i.e. a rare earth metal with an atomic number at least equal to 62, that is in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets. It also relates to a hydrometallurgical process which makes it possible to selectively recover, on the one hand, at least one heavy rare earth metal present in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets and, on the other hand, at least one “light” rare earth metal, i.e. a rare earth metal with an atomic number at most equal to 61, that is also in this acidic aqueous phase. The invention has in particular an application in the recycling of rare earth metals present in spent or scrapped permanent magnets of the type Neodymium-Iron-Boron (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, and also in the recycling of samarium present in spent or scrapped permanent magnets of the type samarium-cobalt (or SmCo).

Disclosed herein is a method for extracting precious metals from supported catalysts. The precious metal in one embodiment is rhodium. The supported catalyst may be from equipment, such as a used catalytic converter. The method is carried out at low temperature, and does not require harsh conditions, such as the use of a strong acid. The method involves contacting the catalytic material with a polar molecule and a reactive gas.

A process for recovering chromium from hexavalent chromium-containing wastewater comprises the following steps: (1) extracting hexavalent chromium in wastewater to an organic phase by using an extracting agent, and separating hexavalent chromium from a water phase, so as to acquire a hexavalent chromium-loaded organic phase; (2) reducing the hexavalent chromium-loaded organic phase by using an aqueous solution of an organic reducing agent, reducing hexavalent chromium into trivalent chromium, reversely extracting trivalent chromium into the water phase, and separating the organic phase from the water phase to acquire a solution of the trivalent chromium and a renewable organic phase, wherein the organic reducing agent is one or a mixture of alcohols, aldehydes and carboxylic acids having the carbon atom number ranging 1 to 3; and (3) performing solvent evaporation on the solution of trivalent chromium, catalyzing, and recovering the trivalent chromium.

A method for extracting rare earth elements from aqueous solution, comprising: (i) acidifying an aqueous solution containing said rare earth elements with an inorganic acid to result in an acidified aqueous solution containing said rare earth elements and containing the inorganic acid in a concentration of 1-12 M, wherein said rare earth elements are selected from lanthanides, actinides, or combination thereof, and (ii) contacting the acidified aqueous solution with an aqueous-insoluble hydrophobic solution comprising a rare earth extractant compound dissolved in an aqueous-insoluble hydrophobic solvent to result in extraction of one or more of the rare earth elements into the aqueous-insoluble hydrophobic solution by binding of the rare earth extractant compound to the one or more rare earth elements, wherein the rare earth extractant compound has the following structure:

##STR00001##

provided that at least one of the conditions (a)-(d) applies.

The present application relates to methods for the simultaneous leaching and extraction of precious metals. For example, the present application relates to methods of leaching and extracting gold and/or palladium from a substance comprising gold and/or palladium such as a gold and/or palladium-containing ore in one step using a compound of Formula I: (I).

The present application relates to methods for the simultaneous leaching and extraction of precious metals. For example, the present application relates to methods of leaching and extracting gold and/or palladium from a substance comprising gold and/or palladium such as a gold and/or palladium-containing ore in one step using a compound of Formula I: (I)