Potential separation of zirconium and some lanthanides of the nuclear and industrial interest from zircon mineral using cation exchanger resin

Abstract

The present study is conducted for developing separation of some elements of nuclear interest from zirconium-concentrate explored from Egyptian zircon mineral, using certain cationic exchangers. The main results revealed that Amberlite IR-120 is more efficient than Chelex-100 for separating La and Zr in 0.01 mol. L⁻¹ (various acid, carbonate) from single or binary solution with separation factor (SF) of ∼2.1 × 10³ (HCl) > 239 (HNO₃) >56 (K₂CO₃) > 17.5 (HClO₄). Separation of La and Zr was largely influenced by acid concentration, equilibration period, and temperature. Thermodynamically, values of$\mathrm{ }\Delta G^o,$ $\Delta H^o$ and$\mathrm{ }\Delta S^o$ indicated that retention of the metal ions is disordered and endothermic nature. In a column application, Zr is separately eluted without La; with recoveries reached to 98% for Zr and 50% to 67% for La. The larger negativity of free energy of hydration of Zr (−6950 KJ/mol) that of La (−3418 KJ/mol) confirm that Zr exists as a non-sorptive species; meanwhile La forms adsorptive species onto the column bed resin. As a result, this study can be extended in the future to help exploration of the strategic elements (e.g., Zr, Hf, lanthanides) from their minerals in Egypt. Moreover, developed procedure by Amberlite IR-120 resin can be considered as highly efficient and promising for separation and purification of tri-valence lanthanides (e.g., La³⁺) and/or actinides (e.g., Am³⁺) from tetra-valence metal ions such as Zr⁴⁺ and Hf⁴⁺ or their homologous as Ce⁴⁺, Th⁴⁺ and Np⁴⁺.

Graphical abstract

Keywords:

• Nuclear elements
• separation process
• ion exchange
• solid phase extraction
• zirconium concentrate