Investigating Impurities Removal Behavior from Terbium by the Combined Plasma Melting and Directional Solidification

The combined argon plasma melting and directional solidification method (denoted as APDS) was innovatively proposed to enhance the purification efficiency of Tb metal in this work. Theoretical computation and experimental analysis were used to explore the removal behavior of the three impurity groups during APDS, which included high volatility impurities of Ca, Mg, Mn and Cr, medium volatility impurity of Ti, and low volatility impurities of Al and Ni. The evaporation removal ratio of Ca and Mg after APDS process exceeds 99.9