A sprayed article is disclosed including a substrate and a sprayed coating deposited thereon and containing a rare earth oxyfluoride as main phase. Provided is a slurry for suspension plasma spraying, which is a spray material used for suspension plasma spraying in an atmosphere including an oxygen-containing gas, contains 5-40 mass % of rare earth fluoride particles having a maximum particle diameter (D100) of 12 m or less, and contains one or more types of solvent selected from among water and organic solvents. A rare earth acid fluoride-containing sprayed film, in which process shift and particle generation hardly occur, can be stably formed on a base material by carrying out suspension plasma spraying in an atmosphere including an oxygen-containing gas. A spraying member provided with this sprayed film exhibits excellent corrosion resistance to halogen-based gas plasma.

A sprayed article is disclosed including a substrate and a sprayed coating deposited thereon and containing a rare earth oxyfluoride as main phase. Provided is a slurry for suspension plasma spraying, which is a spray material used for suspension plasma spraying in an atmosphere including an oxygen-containing gas, contains 5-40 mass % of rare earth fluoride particles having a maximum particle diameter (D100) of 12 m or less, and contains one or more types of solvent selected from among water and organic solvents. A rare earth acid fluoride-containing sprayed film, in which process shift and particle generation hardly occur, can be stably formed on a base material by carrying out suspension plasma spraying in an atmosphere including an oxygen-containing gas. A spraying member provided with this sprayed film exhibits excellent corrosion resistance to halogen-based gas plasma.

The present invention provides a method for recovery, extraction and separation of rare earth elements from rare earth containing materials such as ore and tailings. In accordance with preferred embodiments, the method of the present invention includes grinding rare earth-containing ores to form ore powder and leaching the powered ore with at least one mineral acid. Further, the method of the present invention includes forming a leach solution of metal ions, forming an aqueous-metal concentrate, and precipitating the aqueous-metal concentrate to selectively remove the metal ions from the leach solution. Further, the method of present invention includes the steps of obtaining a precipitate of the rare earth elements, mixing the precipitate with ammonium salt and subjected the mixture to an electrowinning process.

A sintered rare earth oxyfluoride compact is composed of Ln.sub.aO.sub.bF.sub.c (wherein Ln is a rare earth element; and a, b, and c each independently represent a positive number, provided that they are not equal to each other) or Ca-stabilized LnOF as a primary phase and LnOF unstabilized with Ca as a secondary phase. The intensity ratio of the XRD peak of the (018) or (110) plane of the unstabilized LnOF to the highest XRD peak of Ln.sub.aO.sub.bF.sub.c is preferably 0.5% to 30%.

A coating material containing an oxyfluoride of yttrium and having a Fisher diameter of 1.0 to 10 m and a tap density TD to apparent density AD ratio, TD/AD, of 1.6 to 3.5. The coating material preferably has a pore volume of pores with a diameter of 100 m or smaller of 1.0 cm.sup.3/g or less as measured by mercury intrusion porosimetry. A coating containing an oxyfluoride of yttrium and having a Vickers hardness of 200 HV0.01 or higher. The coating preferably has a fracture toughness of 1.010.sup.2 Pa.Math.m.sup.1/2 or higher.

Disclosed are a material for spray for plasma spray coating having high plasma resistance and a method for producing the same. The material for plasma spray comprises an yttrium compound, and the numbers of moles of Y (yttrium), O (oxygen), and F (fluorine) in the yttrium compound satisfy 1.5<(O+F)/Y<2.0.

Disclosed are a material for spray for plasma spray coating having high plasma resistance and a method for producing the same. The material for plasma spray comprises an yttrium compound, and the numbers of moles of Y (yttrium), O (oxygen), and F (fluorine) in the yttrium compound satisfy 1.5<(O+F)/Y<2.0.

Provided is a slurry for suspension plasma spraying, which is a spray material used for suspension plasma spraying in an atmosphere including an oxygen-containing gas, contains 5-40 mass % of rare earth fluoride particles having a maximum particle diameter (D100) of 12 ?m or less, and contains one or more types of solvent selected from among water and organic solvents. A rare earth acid fluoride-containing sprayed film, in which process shift and particle generation hardly occur, can be stably formed on a base material by carrying out suspension plasma spraying in an atmosphere including an oxygen-containing gas. A spraying member provided with this sprayed film exhibits excellent corrosion resistance to halogen-based gas plasma.

Provided is a slurry for suspension plasma spraying, which is a spray material used for suspension plasma spraying in an atmosphere including an oxygen-containing gas, contains 5-40 mass % of rare earth fluoride particles having a maximum particle diameter (D100) of 12 ?m or less, and contains one or more types of solvent selected from among water and organic solvents. A rare earth acid fluoride-containing sprayed film, in which process shift and particle generation hardly occur, can be stably formed on a base material by carrying out suspension plasma spraying in an atmosphere including an oxygen-containing gas. A spraying member provided with this sprayed film exhibits excellent corrosion resistance to halogen-based gas plasma.

An yttrium oxyfluoride is represented by YOF and is stabilized by a fluoride represented by CaF.sub.2. Preferably, the number of moles of Ca with respect to 100 mol of yttrium is from 8 to 40 mol. A powder material is made of a first powder mixture including a calcium fluoride powder represented by CaF.sub.2 and an yttrium oxyfluoride powder represented by YOF, or a second powder mixture including a calcium fluoride powder represented by CaF.sub.2, an yttrium fluoride powder represented by YF.sub.3, and an yttrium oxide powder represented by Y.sub.2O.sub.3. A production method involves firing a molded product of the first or second powder mixture under predetermined conditions.