Erbium, Ytterbium, Thulium and Lutetium Oxides: Xenotime Separated on Ion Exchange Columns with EDTA and HEDTA (Spedding and Powell, US 2,956,858)

The heavy rare earths sit side by side in xenotime and behave almost alike. Spedding and Powell first split off the heavy group with EDTA, then wash it down a long train of resin columns with HEDTA, which takes the rare earths off one after another, heaviest first. Result: from 1750 lb of xenotime, about 26 kg of ytterbium oxide, 23 kg of erbium oxide, 3.7 kg of thulium oxide and 2.8 kg of lutetium oxide, all better than 99.9 % pure. Source: F. H. Spedding and J. E. Powell, US 2,956,858 (1960), the Example. Hot strong sulfuric acid burns; wear acid protection. Picture drawn by Youblob.