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

Despite its ubiquity during the binding and sensing of fluoride, the role of bifluoride (HF2–) and its binding properties are almost always overlooked. Here, we give one of the first examinations of bifluoride recognition in which we use computer-aided design to modify the cavity shape of triazolophanes to better match with HF2–. Computational investigation indicates that HF2– and Cl– should have similar binding affinities to the parent triazolophane in the gas phase. Evaluation of the binding geometries revealed a preference for binding of the linear HF2– along the north–south axis with a smaller Boltzmann weighted population aligned east–west and all states being accessed rapidly through in-plane precessional rotations of the anion. While the 1H NMR spectroscopy studies are consistent with the calculated structural aspects, binding affinities in solution were determined to be significantly smaller for the bifluoride than the chloride. Computed geometries suggested that a 20° tilting of the bifluoride (s...

An Overlooked yet Ubiquitous Fluoride Congenitor: Binding Bifluoride in Triazolophanes Using Computer-Aided Design

https://escholarship.org/content/qt7b39n188/qt7b39n188.pdf?t=p9jr5i

Selective recovery of niobium and tantalum from low-grade concentrates using a simple and fluoride-free process

A review on extractive metallurgy of tantalum and niobium

https://hal.univ-lorraine.fr/hal-02182966/document

M.J. Kabangu

Papers

Separation of niobium and tantalum from Mozambican tantalite by ammonium bifluoride digestion and octanol solvent extraction