To obtain an aluminum refined product having high purity by a segregation solidifying method by promoting the separation of residual molten metal having high impurity concn. from the refined product.
The molten raw material of aluminum is held in a refining furnace with the atmospheric temp. kept at in the range of (primary crystal crystallizing temp.-90°C) to (primary crystal crystallizing temp.-10°C), and α-Al crystal is crystallized on a cooling body dipped in the molten raw material. The cooling body stuck with a prescribed quantity of the α-Al crystal is pulled up from the molten raw material and held in the space in the furnace between the molten raw material and the furnace cover, and the α-Al crystal stuck to the cooling body is separated from the molten raw material and recovered as the refined product. The residual molten metal having high impurity is centrifugally separated by rotating the cooling body at 0.1-0.4 m/sec peripheral speed of the outer periphery at the time of puling up, too. At the time of combining the rotation of the cooling body with the atmospheric control in the furnace, the separation of the residual molten metal having high impurity is further promoted.
WATANABE YASUHIKO
SANO TAKESHI
KUBOTA NOBORU