METHOD FOR PREVENTING DROP OF SOLIDIFIED EVAPORATED METALLIC IMPURITY IN MELTING FURNACE AND SOLIDIFIED EVAPORATED ALUMINUM IN MELTING FURNACE FOR NIOBIUM REFINING, AND MELTING FURNACE THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for preventing the solidified Al which is the impurity from being dropped into an ingot in refining Nb using a vacuum melt ing furnace. ;SOLUTION: Nb-Al alloy 19 is melted in vacuum by heating means 17, 18, and stored on a hearth 14 arranged in a melting furnace and Al is evaporated to refine Nb. The refined Nb is moved to a water-cooled crucible 16 to cast an Nb ingot 15. A rotary body 20 having a cooling means is provided on the water-cooled crucible 16, and a net 22 which is formed by knitting stainless steel wire is mounted on a lower part of the rotary body 20 in an attachable/ detachable manner to adhere the evaporated Al to the net and solidify it thereon in an approximately uniform and dense manner.;COPYRIGHT: (C)1999,JPO