Removal of non-metallic impurities from molten metal - by contact with fused alkali(ne earth) halide flux and vigorous agitation

摘要

Molten metal (esp. Al) is poured into a vessel and its surface covered with =0.69 g/cm2 of fused salt flux. The rate of addn of metal is controlled to give a residence time in the vessel of =0.5 mins. during which metal and flux are agitated. The compsn. of the flux can be varied according to the metal being treated, impurities contained and risk of contamination of the metal by the flux. The need for a protective atmos. is obviated and capital/running costs considerably reduced. Method is suitable for the prodn. of fault free ingots used for subsequent forming.