Process Applications and Challenges in Mineral Beneficiation and Recovery of Niobium from Ore Deposits – A Review

Niobium and tantalum recovery from the primary source and from tin slag, an industrial challenge: A review

“…The mineralogy of Nb and Ta deposits was reported by Nzeh et al [ 19 ] Basically, Nb usually occurs with carbonites and sulphides, while Ta occurs in pegmatites deposits. The most important industrial resources of Nb and Ta are columbite, tantalite, columbite/tantalite (coltan), and pyrochlore.…”

“…Its composition may vary between 40% to 75% Nb 2 O 5 and from 1% to 40% Ta 2 O 5 . [ 1,19 ] Columbite deposits are found in Brazil, Australia, and Nigeria. [ 20 ] Ta can also be extracted from microlite, wodginite, and struvite, but columbite/tantalite is still the leading resource.…”

“…The increase in metal concentration is a necessity to make feasible Nb and Ta extraction from their mineral deposits, and it was reported that the best scenario may present 25% Nb/Ta or 50% of their combination. [ 19 ] The techniques used in the industry to reach the metal content are the fourth flotation, using hydrofluoric acid (HF), fluorosilicic acid (H 2 SiF 6 ), oxalic acid (H 2 C 2 O 4 ), and hydrochloric acids (HCl) activators, pH stabilizers, and silicate depressants. Other techniques that can be used are concentration techniques, the reverse gangue flotation, direct flotation, gravity concentration (jigs, shake tables, sluices, air floaters, and spiral concentrators), magnetic separation, electrostatic separation, mineral decomposition, and leaching dissolution.…”

“…Other techniques that can be used are concentration techniques, the reverse gangue flotation, direct flotation, gravity concentration (jigs, shake tables, sluices, air floaters, and spiral concentrators), magnetic separation, electrostatic separation, mineral decomposition, and leaching dissolution. [ 19 ] Density separation is driven by the metal content, high Ta concentration, increasing the ore density, and making suitable the gravity concentration processes. [ 18 ] Coltan can be magnetically concentrated, removing nonmagnetic components such as cassiterite, and concentrating Nb and Ta in a paramagnetic stream without ilmenite.…”

“…The fluoride decomposition or dissolution depends on temperature, acidity, and concentration of F − . [ 19 ]…”