Recovery of hydrogen fluoride from aqueous solution containing ammonium fluoride and hydrogen fluoride

摘要

A method of recovering HF from an aqueous solution containing NH₄F and HF is provided. The solution is contacted with a water-immiscible, amine-containing extractant which extracts HF in preference to NH₄F. The HF:NH₄F molar ratio of the solution, the amine, the concentration of the amine in the extractant and the contact temperature are selected so as to form an HF-loaded organic liquid phase having an HF:amine molar ratio of at least about 1.2. The extractant is preferably selected from amines, amine-HF complexes, quaternary amine fluorides and mixtures thereof with inert organic diluents. After equilibration, the HF-loaded amine is separated from the solution and HF is stripped therefrom in an amount sufficient to lower the HF:amine molar ratio by at least about 0.2.