Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as Cl- and SO4—. This is ascribed to the copolymerisation of Nbv and the hydrolyzed ionic species of ZrIVv and HfIV by which the colloidal particles are masked as Zr- and Hf-compounds.
In HCl the particles are positively charged as opposed to when they are in sulphate solution where the Zr- and Hf-sulphate complexes confer a negative charge. The two cases are considered separately.
|Place of Publication||Roskilde|
|Publisher||Risø National Laboratory|
|Number of pages||24|
|Publication status||Published - 1987|
|Series||Denmark. Forskningscenter Risoe. Risoe-R|