Nd³⁺ and Dy³⁺ can be separated in an acidic ethanol–water by fractional precipitation as phosphoester coordination polymers.

The separation performance was found to be better in HNO₃ than in HCl media.

The Dy molar ratio to the total metal content was over 99% at c(H⁺) ∼ 0.15 mol L⁻¹ in HNO₃ medium.

Association between ${\text{NO}}_3^{-}$ and Nd³⁺ plays an important role in an increase in the separation performance.