Über die Erbinerde

The Basicity Characteristics of Scandium, Yttrium, and the Rare Earth Elements.

“…The precipitates were granular and easy to filter. Krüss and his coworkers (231,232,233,234) employed the method successfully for the partial separation of small amounts of the erbium and gadolinium earths but found it useless for large amounts of material. Kolb (221) employed aniline in aqueous solution to precipitate thorium and thus separate it from the cerium earths.…”

“…was recommended by Kriiss (233) as an excellent means of separating the yttrium earths, the course of the separation paralleling that of precipitation with aniline (233). The utility of this method as a means of concentrating the gadolinium, terbium, and holmium earths has been demonstrated (169,170,233,234). Details of the procedure have been excellently summarized by Spencer (379).…”

“…Crookes(93) purified yttrium by nitrate fusion and used Debray's modified procedure to remove cerium (94) and to separate scandium from ytterbium (97). Prior to 1910, nitrate fusion was used by many other workers to fractionate the yttrium earths(22,23,40,81, 169,212,234,367,369) and the cerium earths(10,22,23,137,331,365,366,443,444). Bettendorff(22) obtained clear melts for the yttrium earths because the melting points lay below the decomposition temperatures but always noted decomposition of cerium earth nitrates before fusion.…”