Interaction of loparite concentrate with ammonium hydrodifluoride

Resumo

Results obtained in a study of the interaction between the loparite concentrate and ammonium hydrodifluoride are reported. It was found that the reactions of the main components of the concentrate with NH₄HF₂ yield complex ammonium fluorometallates. It was shown that water leaching of the fluorinated product makes it possible to transfer niobium and tantalum into solution together with fluoroammonium salts of titanium and silicon and to concentrate rare-earth elements in the insoluble residue in the form of complex salts of general formula NaLnF₄.