A polycrystalline diamond element leaching assembly includes a polycrystalline diamond element, a protective leaching cup surrounding at least a portion of the polycrystalline diamond element, and a protective layer positioned between the polycrystalline diamond element and the protective leaching cup. A method of processing a polycrystalline diamond element includes covering a selected portion of a polycrystalline diamond element with a curable resin layer, curing the curable resin layer to form a protective layer, and exposing at least a portion of the polycrystalline diamond element to a leaching agent. Another method of processing a polycrystalline diamond element includes depositing a curable resin within a protective leaching cup and positioning a polycrystalline diamond element within the protective leaching cup such that the curable resin is displaced so as to surround at least a portion of the polycrystalline diamond element.

Disclosed is a method for processing ash, particularly fly ash, in which method several elements are separated from the ash. In the method both noble metals and rare earth elements are separated.

A method of producing enriched .sup.47Sc comprises irradiating a V structure comprising .sup.51V with at least one incident photon beam having an endpoint energy within a range of from about 14 MeV to about 44 MeV to convert at least some of the .sup.51V to .sup.47Sc and form a .sup.47Sc-containing structure. The .sup.47Sc of the .sup.47Sc-containing structure is separated from additional components of the .sup.47Sc-containing structure using a chromatography process. Systems and apparatuses for producing enriched .sup.47Sc are also described.

A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

A method for extracting and separating rare earth elements comprising providing a rare earth-containing ore or tailings, grinding the rare earth-containing ore to form powdered ore; leaching the powered ore with at least one mineral acid, forming a leach solution comprising at least one metal ion, rare earth elements and a solid material, separating the solid material from the leach solution to form aqueous-metal concentrate, precipitating the aqueous-metal concentrate to selectively remove the metal ion from the leach solution and obtain a precipitate of the rare earth elements; heating the precipitate of the rare earth elements in air to form oxide of the rare earth elements, mixing the oxide of the rare earth elements with an ammonium salt and heating in a dry air/nitrogen, forming a mixture of anhydrous rare earth salts in an aqueous solution, and separating the rare earth elements from the aqueous solution by means of an electrowinning process.

A method for extracting and separating rare earth elements comprising providing a rare earth-containing ore or tailings, grinding the rare earth-containing ore to form powdered ore; leaching the powered ore with at least one mineral acid, forming a leach solution comprising at least one metal ion, rare earth elements and a solid material, separating the solid material from the leach solution to form aqueous-metal concentrate, precipitating the aqueous-metal concentrate to selectively remove the metal ion from the leach solution and obtain a precipitate of the rare earth elements; heating the precipitate of the rare earth elements in air to form oxide of the rare earth elements, mixing the oxide of the rare earth elements with an ammonium salt and heating in a dry air/nitrogen, forming a mixture of anhydrous rare earth salts in an aqueous solution, and separating the rare earth elements from the aqueous solution by means of an electrowinning process.

A method of processing a pyrite-containing slurry including removing pyrite from the pyrite-containing slurry and forming (i) an inert stream and (ii) a pyrite-containing material. Using the pyrite-containing material in a downstream leach step in which pyrite in the pyrite-containing material generates acid and heat that facilitates leaching a metal, such as copper or nickel or zinc or cobalt, from a metal-containing material.

A method of processing a pyrite-containing slurry including removing pyrite from the pyrite-containing slurry and forming (i) an inert stream and (ii) a pyrite-containing material. Using the pyrite-containing material in a downstream leach step in which pyrite in the pyrite-containing material generates acid and heat that facilitates leaching a metal, such as copper or nickel or zinc or cobalt, from a metal-containing material.

A process of extracting copper from copper sulphide minerals which is enhanced at solution potentials exceeding 700 mV SHE, in the absence of any microorganism, by contacting the minerals in a pre-treatment phase using an acid solution at a high chloride content containing dissolved copper.