| Vacuum distillation at 10^(-5) Torr was carried out to refine indium and gallium metal under various conditions. Recovery of both metals decreased with the increase of temperature and reaction time. Activation energies of indium and gallium for vacuum distillation were found to be 32.9㎉/mole and 83.2㎉/mole, respectively, and distillation rates of both metals were controlled by evaporation rate at the interface. It was possible to produce 99.999% indium metal from the starting material of 99.97% at 1000℃ within 1 hour. When gallium of 99.9% purity was refined at 1050℃, Bi, Pb, Zn and Mg were eliminated to less than 1ppm but only 25% of Fe and 80% of Ca were eliminated to produce 99.99% gallium metal within 2 hours. |
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