Refined magnesium material and method for producing the same

Abstract

A process for producing a refined magnesium material which is flame retardant by adding an alkaline earth metal. In the process, the dross in a thin film is formed on the surface of the molten magnesium material by contacting it with a dross-formable atmosphere gas while the molten magnesium material is subjected to a vertical vortex flow. The dross encloses the impurity floating on the surface of molten magnesium material through the vortex flow in a vertical direction. The resultant dross is accumulated at the corner of the crucible to prevent the re-diffusion of the impurity. The continuous application of the vortex flow against the molten magnesium material causes the thin film of dross to be continuously formed on the molten magnesium material and adhered thereto so as to enclose the impurity each time it is formed. Accordingly, the molten magnesium material is improved in cleanliness or refined. Solidifying the molten magnesium material by cooling serves to provide an ingot for casting which is extremely reduced in the porosity peculiar to the addition of an alkaline earth metal. Casting such the ingot serves to provide a product having good qualities.

Dependencies are inferred from the claim text.