Crystallization field and rate study for the formation of single phase sodium‐potassium and potassium clinoptilolite

Reproducible synthesis of clinoptilolite as the single crystalline phase was achieved in the narrow crystallization field at or around the nominal batch composition of 2.1(Na₂O+K₂O):Al₂O₃:10SiO₂:110H₂O at 140 °C. Clinoptilolites of high purity were crystallized in the pure sodium or mixed sodium‐potassium cation systems. Partial replacement of hydroxyl anions with the salts of carbonates or chlorides also yielded clinoptilolite as the single crystalline phase although at lower crystallization rates. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)