Preparation of 7N High-Purity Indium by Vacuum Distillation- Zone Refining Combination

Abstract:

High-purity indium finds extensive application in the aerospace, electronics, medical, energy, and national defense sectors. Its purity and impurity contents significantly influence its performance in these applications. High-purity indium was prepared by combining zone refining with vacuum distillation. Results show that the average removal efficiency of impurity Sb can approach 95%, while the removal efficiency of impurities Sn and Bi can reach over 95%, and the removal efficiency of Si, Fe, Ni, and Pb can reach over 85%. Ultimately, the amount of Sn and Sb impurities is reduced to 2.0 and 4.1 μg/kg, respectively, and that of most impurities, including Fe, Ni, Pb, and Bi, is reduced to levels below the instrumental detection limit. The average impurity removal efficiency is 90.9%, and the indium purity reaches 7N9.