Patent ID: 6309441
Filing Date: 2001-10-30
Classification: C22B,H01F

Abstract:
A reduction-melting process to form rare earth alloy compositions used in permanent magnets comprising the steps of:adding to a molten slag halide flux containing a reducing agent at least one rare earth oxide, at least one transition metal compound and a boron containing-compound to be reduced;placing a non-consumable electrode in contact with the electroslag halide flux;passing a current through said electrode into the molten flux to reduce the rare earth oxide, the transition metal compound and the boron containing-compound while forming oxide byproducts in the slag;collecting a rare earth-transition metal-boron reduced compound droplets falling through the slag;forming a refined ingot of said rare earth-transition metal-boron reduced droplets in a cooled crucible; andsolidifying the slag containing oxide byproducts.