Erbium: Twice-Distilled Chloride Reduced by Lithium Vapour at 900 °C, then Sublimed at 1425 °C (Croat, Ames 1969)

Erbium chloride, dried with ammonium chloride and distilled twice, is reduced by lithium vapour inside a closed tantalum retort; the lithium chloride is distilled away, and the metal is sublimed and arc melted. Result: erbium metal, 99.98 % by weight; 1000 g of chloride gave 603 g of metal. Source: J. J. Croat, The preparation of high purity dysprosium, holmium and erbium by the lithium reduction of their trichloride salts (Iowa State University / Ames Laboratory, 1969). Hydrochloric acid is corrosive; washing out lithium residues releases hydrogen, which can explode. Picture drawn by Youblob.