Method for separating Dy and Tb from alloy containing both
An object of the present invention is to provide a method for separating Dy and Tb from an alloy containing Dy and Tb as constitutional metals without using a solvent extraction method. The method of the present invention as a means for resolution is characterized by comprising vaporizing Dy by subjecting the alloy to a heat treatment in an atmosphere of a pressure Pt(Pa) that, when a Dy—Tb composition in the alloy is Dy x Tb y (atomic composition ratio) and a heat treatment temperature is t, satisfies formula 1: Pt Tb <Pt<Pt Dy ×(x/(x+y)), wherein Pt Dy is a vapor pressure (Pa) of Dy alone at the temperature t and Pt Tb is a vapor pressure (Pa) of Tb alone at the temperature t.
1. A method for separating Dy and Tb from an alloy containing Dy and Tb as constituting metals characterizing by comprising vaporizing Dy by subjecting the alloy to a heat treatment in an atmosphere of a pressure Pt(Pa) that, when a Dy—Tb composition in the alloy is Dy x Tb y (atomic composition ratio) and a heat treatment temperature is t, satisfies formula 1: Pt Tb <Pt<Pt Dy ×(x/(x+y)), wherein Pt Dy is a vapor pressure (Pa) of Dy alone at the temperature t and Pt Tb is a vapor pressure (Pa) of Tb alone at the temperature t;
wherein the method is characterized in that the vaporized Dy is captured in a getter, wherein a material of the getter is Fe, and wherein the form of the getter is a particle or powder form having a particle size of 1 mm or less.
2. The method according to claim 1 characterized in that the heat treatment temperature t is 900° C. to 1500° C.
3. The method according to claim 1 characterized in that Dy is vaporized from the alloy until x/(x+y) becomes 0.1 or less.
4. The method according to claim 1 characterized in that each of Dy and Tb contained in the alloy is derived from an R—Fe—B based permanent magnet.