This review paper discusses the extraction processes of niobium and tantalum, encompassing hydrometallurgical, pyrometallurgical and electrometallurgical methods. The hydrometallurgical approach discussed includes ore preparation, leaching, solvent extraction, solid–liquid separation, fractional crystallisation and precipitation. The pyrometallurgical processing includes calcination, roasting and smelting techniques. And the electrometallurgical methods include electrowinning, electrofining processes along with two basic approaches of electrometallurgy called aqueous processing and fused-salt processing. Environmental concerns in relation to the extraction of these metals and newer development trends are also discussed within each process. The paper also compares existing methodologies, and provides the author's opinion on the three processes including the current state of the arts.
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