| 摘要 |
A process for removing impurities such as Fe, Si and Ga from aluminium comprises removing the heat from molten aluminium substantially only through the metal-air interface with or without a flux covering so that discrete crystals, having an aluminium content higher than the starting material, are formed which drop under the influence of gravity. These crystals may be compacted to expel some of the mother liquor, not more than half the area of the bath being tamped at each stroke and the whole area being covered at least once every 10 minutes preferably once every 3-5 minutes. The mother liquor is then drained off and the crystals are remelted in at least two stages to give first a mass of higher purity than at the start and finally the very purest fraction. The addition of boron to remove titanium as the boride is also referred to. |
