2R(NO₃)₃,3Mg(NO₃)₂,24H₂O. ||| +--------------------------------+|| | +---------------+|+---------------+ | | | | ~1~ ~2~ ~3~ ~4~ La, Pr Pr, Nd Crude Nd Mother-liquors. Compounds. Compounds. Compounds. Fractionate as Fractionate as Continue the Sa, Eu, Gd, etc. R(NO₃)₃,2NH₄NO₃, 2R(NO₃)₃, Separation. Crystallise with 4H₂O. 3Mn(NO₃)₂,24H₂O. | Bismuth magnesium | | | nitrate. | | +-------+ | | | | | +-------------+ +---------+-------------+| | Terbium | | | || | elements. | | | || | | | | || +---+ | | | || | ~5~ ~6~ ~7~ ~8~ ~9~ Pure ~La~ Pr with La. Impure Pr Pure ~Nd~ Pure ~Sa~ Compound. Compound. Compound. Compound. Refine by Continue. Continue. Refine by Sulphate | | Sulphate crystallisa- | | crystallisa- tion. | | tion. | | +--------+-----+ +----+ | | | Mixture of ~Pr.~ Pr, La. Refine by Sulphate crystallisation. FIG. 8.--SEPARATION OF THE CERIUM ELEMENTS] SEPARATION