Method for the extraction of impurities by natural radioisotope free fluorides and/or oxides of niobium and tantalum from complex uranium, thorium, radium, titanium and rare earth earth earth earth acids

摘要

In a process for recovering earth metal acid compounds free from radiation from earth metal-acid ores containing, in complex and other forms, uranium, thorium and radium, the crushed ore is first subjected to a treatment, after which all the uranium is present in only one oxidation state in which it cannot transfer into the phase containing the earth metal acid compounds during digestion. For this purpose, the ore can be digested using sulphuric acid, uranium and thorium going into solution and the earth metal acid compounds remaining in the solid residue. In other potential methods, the ore is digested using hydrofluoric acid and a simultaneous reduction of the uranium to U(IV) occurs, so that niobium and tantalum go into solution, but uranium and thorium remain in the solid residue. The solid residue is further treated in the first case with hydrofluoric acid to recover Ta and Nb, and in the second case, if required, with sulphuric acid to recover U.