POTENTIOMETRIC TITRATION OF NATURAL CLINOPTILOLITES

Abstract

Acid-base properties of zeolite tuffs of Cheboksary, Holin and Tedzamy deposits were studied by potentiometric titration of their decationized forms with HСl solution at concentration of background electrolyte 1 M and 0.1 M КСl. The acidity parameters of individual types of the clinoptilolite ion-exchange centers of have been calculated from the titration curves of the zeolites using the method of computer modelling of potentiometric titration data suggested earlier. The full exchange capacities were determined by К⁺ ion using static and dynamic methods. Potentiometric titration was carried out by the titration of the zeolites using one sample method. The clinoptilolites contain at least three types of the sorption centers. They differ in the acid strength expressed by the pK parameter and its dependence of the degree of neutralization ∆pk. The amount of strong acidic groups (pK₁= 0.2) is 0.13–0.26 m-eq/g. The number of weak acid groups in the samples of clinoptilolites is different (pK₂ > 3 and pK₃ > 7).