Sorption of transition metal cations on natural heulandite

The cation exchange equilibrium in the systems of natural heulandite-binary aqueous solutions of NaCl, NiCl₂, CuCl₂, ZnCl₂, and MnCl₂ was studied. The corrected coefficients of the selectivity (k^a_M/Na) and thermodynamic constants (K_M/Na) of the cation exchange of Na⁺ cations for transition metal cations were determined. The selectivity of the cation exchange on natural heulandite increases in the following order: Ni²⁺ < Cu²⁺ < Zn²⁺ < Na²⁺ < Mn²⁺.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1101–1103, May, 1996.