Provided is a method for electrowinning neodymium compound. The method includes providing a fluoride-based electrolyte through an opening defined in an electrolytic bath including a cathode and an anode. The method includes providing granules, each including a neodymium compound and having at least one cavity defined therein, through the opening defined in the electrolytic bath. The method includes dissolving at least a portion of the granule in a molten salt of the fluoride-based electrolyte. The method also includes reducing neodymium at the cathode. The cavity is defined inside or on the surface of the granule, and the apparent density of the granules is lower than the density of the molten salt. The method proposed has an improved process compared to those of the related art.

Methods are provided for forming high temperature coating over ceramic components, such as ceramic turbomachine components. In various embodiments, the method includes the step or process of at least partially filling a reactor vessel with a reaction solution containing a solution-borne rare earth cation source. A silicon-containing surface region of a ceramic component is submerged in the reaction solution, and a solvothermal growth process is carried-out. During the solvothermal growth process, the reaction solution is subject to elevated temperature and pressure conditions within the reactor vessel in the presence of a silicate anion source, which reacts with the solution-borne rare earth cation source to grow a rare earth silicate layer over the silicon-containing surface region of the ceramic component.

Disclosed are rare earth phosphate particles that include aggregated particles formed of a plurality of primary particles of a rare earth phosphate represented by LnPO.sub.4, wherein Ln represents at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu. The cumulative volume particle size at a cumulative volume of 50 vol %, D.sub.50, of the aggregated particles is from 0.1 m to 20 m as measured through particle size distribution analysis using a laser diffraction and scattering method. The rare earth phosphate particles are to be distributed in a substrate or on a surface of a substrate and used to cause scattering of light.

A method is provided for separating and/or purifying different metal oxalates by mixing the different metal oxalates in an aqueous solution comprising oxalic acid and an organic base so that at least one metal oxalate is soluble and at least another metal oxalate is not soluble. Different rare earth metal oxalates and/or transition metal oxalates can be separated.

The film is formed using one of two film-forming materials. The first film-forming material contains: particles containing a crystal phase of a rare earth element fluoride; particles containing a crystal phase of a rare earth element oxide; and particles containing a crystal phase of a rare earth element ammonium fluoride double salt. The second film-forming material contains: particles containing a crystal phase of a rare earth element fluoride; and particles containing a crystal phase of a rare earth element oxide and a crystal phase of a rare earth element ammonium fluoride double salt. If a spray coated film is to be formed by means of thermal spraying using this film-forming material or film-forming slurry in particular, it is possible to form a rare earth element oxyfluoride spray coated film without the need for excessive heat.

A system including a material is described. The material includes at least one rare earth (R), hydrogen (H), and at least one dopant (D). The material includes R, H, and D with R:H:D in a ratio of 1:x:y, where x is greater than 2 and less than 3, and y is at least 0.4 and less than 1.

The present disclosure describes an eco-friendly bio-based process for effectively recovering a rare earth metal from a rare earth metal source, particularly a low-grade phosphate mineral such as monazite, through solvo-chemical extraction.

The present disclosure describes an eco-friendly bio-based process for effectively recovering a rare earth metal from a rare earth metal source, particularly a low-grade phosphate mineral such as monazite, through solvo-chemical extraction.

Despite the abundance of scandium, its commercial applications continue to be limited by the absence of reliable, secure, stable and long-term production. The subject-matter disclosed herein provides for a method for extracting Rare Earth Elements (REE), scandium and/or Rare-Earth Oxides (REO) from ore and mineral concentrates, the method comprising: providing Rare Earth Elements (REE) and/or scandium bearing feedstock; a high-pressure caustic (HPC) leaching step, comprising leaching the feedstock in an alkali solution at a first temperature for a target period of time and at a given pressure to produce a leachate slurry; extracting a solid residue from the leachate slurry; leaching of the solid residue in a mineral acid to form a primary leach solution; extracting scandium and/or REE from the primary leach solution; and/or precipitating REE remaining in the raffinate to form a mixed REE-carbonate to thereby facilitate the extraction of REO.

Despite the abundance of scandium, its commercial applications continue to be limited by the absence of reliable, secure, stable and long-term production. The subject-matter disclosed herein provides for a method for extracting Rare Earth Elements (REE), scandium and/or Rare-Earth Oxides (REO) from ore and mineral concentrates, the method comprising: providing Rare Earth Elements (REE) and/or scandium bearing feedstock; a high-pressure caustic (HPC) leaching step, comprising leaching the feedstock in an alkali solution at a first temperature for a target period of time and at a given pressure to produce a leachate slurry; extracting a solid residue from the leachate slurry; leaching of the solid residue in a mineral acid to form a primary leach solution; extracting scandium and/or REE from the primary leach solution; and/or precipitating REE remaining in the raffinate to form a mixed REE-carbonate to thereby facilitate the extraction of REO.