Separation and isolation of tantalum and niobium from tantalite using solvent extraction and ion exchange

•Tantalum and niobium were successfully separated from each other in tantalite.•Solvent extraction succeeded in removing tantalum from the tantalite matrix.•Ion exchange separated niobium from the rest of the metal impurities.•Quantitative recoveries were obtained for both tantalum and niobium.

A step-wise separation process for niobium and tantalum from tantalite by extraction and ion exchange was developed. A tantalite mineral was dissolved by a fusion technique using ammonium bifluoride as flux. Tantalum and niobium form stable anionic fluoride complexes in fluoride solutions. This fact was used to develop an analytical method to separate tantalum and niobium from other metals within the tantalite mineral and from each other.Tantalum was separated from the rest of the mineral matrix by solvent extraction using methyl isoamyl ketone. The analytical results indicated that 98.9(9)% Ta2O5 was recovered from the organic portion while 101.6(3)% Nb2O5 and the rest of the elements were recovered from the aqueous solution. Niobium was subsequently separated from the tantalite matrix by anion exchange technique using Dowex Marathon resin and HCl solution as a mobile solvent. The analytical results indicated Nb2O5 recovery of 101(2)%.