A study on solvent extraction of niobium from nitric acid solution: Pt. 5

The behaviour of extraction of niobium with TBP in presence of molybdenum and zirconium, uranium, or praseodymium in the aqueous phase is studied. The dependence of extraction of niobium with TBP on the concentrations of zirconium in 1 ∼ 8 mol/l HNO3 is described. The results show: 1. In the concentrations of 1 x 10-3 mol/l<[Zr]<5 x 10-2 mol/l, due to the action of zirconium, DNb is increased with increasing of Zr concentration when the concentration of nitric acid is higher than 4 mol/l, and DNb is decreased with the concentration of nitric acid is higher than 4 mol/l, and DNb is decreased with increasing of Zr concentration when the concentration of nitric acid is lower than 4 mol/l. 2. DNb increases when molybdenum and zirconium are present simultaneously in aqueous phase. DNb appears minimum when the concentration of molybdenum and zirconium are less than 1 x 10-2 mol/l and the concentration of nitric acid is at 3 mol/l