The extraction experiment was conducted using several
self-devised apparatuses shown in Fig. 2. Nd–Fe–B alloy
scrap(Fe–31 mass%Nd–1 mass%B, Mass of scrap: wscrap ¼
70{250 g), which was pulverized into chips less than a few
mm in size, was placed in an iron crucible with slits of 1–
2 mm width. The crucible was fixed to and suspended from
the top of a stainless steel reaction vessel. A tantalum
crucible for recovering the Mg–Nd alloy was placed in the
bottom part of the reaction vessel. Lumps of Mg
(99.95 mass%, Mass of Mg: wMg ¼ 30{70 g) were placed
in the tantalum crucible, and the reaction vessel was sealed
by TIG welding. The extraction was carried out by placing
the reaction vessel in an electric furnace. The bottom part of
the reaction vessel was heated to a temperature of 1073–
1273 K (High temperature zone: T bottom) by controlling the
output of the furnace, while the top part was adjusted to a
temperature of 1002–1207 K (Low temperature zone: T top) by
supplying coolant gas from the top of the furnace through a gas tube. The experiment was conducted for approximately
86–259 ks (24 to 72 h).