Physicochemical and structural characteristics of HEU-type zeolitic tuff treated by hydrochloric acid

Samples of natural HEU-type zeolites clinoptilolite-Ca, from the Novakovici deposit (near Prijedor, Bosnia and Herzegovina) were treated with the hydrochloric acid of various concentrations (from 10-3 M to 2 M). Zeolitic tuffs before and after the acid treatment were examined using IR, XRPD, and chemical analyses. The changes in the crystal structure of acid treated samples showed a significant reduction in the crystallinity of zeolitic tuffs (60 70 %), which were effected by hydrochloric acid with concentrations of 1 M and above.