The concentrated ore undergoes solvent extraction and ion exchange processes to separate rare earth elements from each other due to their similar chemical properties. Terbium is isolated as terbium oxide (Tb₄O₇) or terbium fluoride (TbF₃).
Reduction using calcium in a vacuum or inert atmosphere furnace:
TbF3 + 3Ca→Tb(metal)+3CaF2
This reaction yields terbium metal sponge or ingots after cooling.
The terium metal is further refined to remove any impurities, ensuring high purity for industrial or commercial use. This may involve additional steps such as vacuum distillation or electrorefining.
Finally, the refined erbium metal is formed into various shapes, such as ingots, sheets, or powders, depending on its intended application. This is done through processes such as melting, casting, and milling.