Obtaining high-purity niobium (V) at decomposition of lithium orthoniobate in fluoride-sulphuric acid medium

The work presents the findings of laboratory investigation and testing of fluoride-sulphuric acid technology, whereby lithium orthoniobate was processed to obtain a high-purity niobium (V) oxide subsequently used in the production of lithium niobate single crystals. The optimal conditions for Li3NbO4 decomposition providing the highest possible level of niobum and lithium transition to solution have been determined. The solvent extraction process of niobium extraction by a mixture of extragents (carboxylic acid dimethyamides of the С10-С13 fraction with Eskeide and octanol-1 as diluents) has been discussed. In the course of experiments, we obtained 10 kg of Nb2O5 satisfying the requirements for the production of LiNbO3.