ABSTRACT
This chapter aims to an account of the sources and various treatment procedures for the metal as it occurs in nature. The cleaner flotation is then performed in four cleaner stages. The first cleaner flotation stage consists of five 8.5-m3 cells, the second of four 4.8-m3 cells, the third and the fourth stages consist of six cells each of 1.7 m3. The concentrate is dried, screened in multideck screens, and then treated further by a sequence of operations involving pneumatic tables, magnetic separation, and electrostatic separation to produce separate fractions of cassiterite, tantalite, and stibioitantalite. The chapter outlines some of the essential process flowsheet details as practised at some of the major niobium sources in the world. Niobium is not an abundant element. It is never present in free, native, or elemental form. It almost always occurs in partnership with tantalum and is found in nature as an oxide in association with other minerals.
