Methods for removing an oxyanion from an aqueous source containing said oxyanion, comprising contacting said aqueous source with an aqueous-insoluble hydrophobic solution containing an oxyanion extractant compound dissolved in an aqueous-insoluble hydrophobic solvent to result in formation of an oxyanion salt of said extractant compound and extraction of said oxyanion salt into said aqueous-insoluble hydrophobic solution, wherein said extraction results in an extraction affinity (D) of said oxyanion of at least 1, wherein D is the concentration ratio of said oxyanion in the organic phase divided by the concentration of said oxyanion in the aqueous phase; wherein said extractant compound has the following composition:

##STR00001##

wherein at least one of R.sup.1-R.sup.10 is or contains a hydrocarbon (R) group containing at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms.

A method of recovering metal compounds from solid oxide fuel cell scrap includes processing the solid oxide fuel cell scrap to form a powder, digesting the processed scrap, extracting lanthanum oxide and cerium oxide from a solution containing the digested processed scrap, extracting a zirconium compound from the solution after extracting the lanthanum oxide and cerium oxide, and extracting scandium compound from the solution extracting the zirconium compound from the solution.

A new 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: 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; anda surfactant. It also relates to the applications of this new extractant: 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.

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.

The present applications 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).

##STR00001##

The present invention relates to a process for efficiently enriching and recovering noble metals of platinum and palladium based on solvent extraction, wherein isoamyl alcohol is used as extracting agent and 2-methoxyphenyl thiourea is used as extraction-assisted complexing agent. 2-methoxy-phenyl thiourea is added to aqueous phase to react with platinum and palladium, and isoamyl alcohol is used as extracting agent to extract the organic phase, thus realizing the purpose of separating and extracting noble metals from base metals while enriching noble metals of platinum and palladium. The present invention, which can not only realize the separation of noble metals and base metals, but also enhance the enrichment and recovery ratios of noble metals of platinum and palladium, with low cost reagents, small influence on the environment and simple technical process, thus is a new and efficient extraction and enrichment system for noble metals.

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.

Provided are a platinum-group metal recovery agent represented by the following general Formula (1) and a platinum-group metal recovery method for recovering platinum from a hydrochloric acid solution containing platinum using the platinum-group metal recovery agent. (In Formula (1), X is a methylene group, an oxygen atom, or an ethylene group; n is 3 when X is a methylene group; and n is 2 when X is an oxygen atom or an ethylene group.)

##STR00001##

Rare earth extractant compounds having the following structure: ##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from alkyl groups containing 1-30 carbon atoms and optionally containing an ether or thioether linkage connecting between carbon atoms, provided that the total carbon atoms in R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is at least 12; R.sup.5 and R.sup.6 are independently selected from hydrogen atom and alkyl groups containing 1-3 carbon atoms; and provided that at least one of the conditions (i)-(iv) apply as follows: presence of a distal branched group in at least one of R.sup.1-R.sup.4 (condition i), asymmetry in R.sup.1-R.sup.4 (condition ii), presence of amine-containing ring (condition iii), or presence of lactam ring (condition iv). Also described are hydrophobic water-insoluble solutions containing at least one extractant compound of Formula (1), as well as method for extracting rare earth elements from aqueous solution by contacting the aqueous solution with the water-insoluble solution.

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.