Patent ID: 6214301
Filing Date: 2001-04-10
Classification: C22B,G21G,Y02P

Abstract:
A method for obtaining hafnium radioisotopes from irradiated tantalum containing lanthanides and hafnium comprising:(a) contacting the irradiated tantalum with at least one acid to obtain a solution of dissolved tantalum;(b) combining an aqueous solution of a calcium compound with the solution of dissolved tantalum to obtain a third combined solution;(c) precipitating hafnium, lanthanide, and insoluble calcium complexes from the third combined solution to obtain a first precipitate;(d) contacting the first precipitate of hafnium, lanthanide and calcium complexes with at least one fluoride ion complexing agent to form a fourth solution;(e) selectively adsorbing lanthanides and calcium from the fourth solution by cationic exchange;(f) separating fluoride ion complexing agent product from hafnium in the fourth solution by adding an aqueous solution of ferric chloride, adjusting the solution to an alkaline pH, and heating to obtain a second precipitate containing the hafnium and iron;(g) dissolving the second precipitate containing the hafnium and iron in acid to obtain an acid solution of hafnium and iron;(h) selectively adsorbing the iron from the acid solution of hafnium and iron by anionic exchange;(i) drying the ion exchanged hafnium solution to obtain hafnium isotopes.