Investigation of the mechanism of interaction at the hydrothermal conditions of zeolite – cubic analcime with the Li+, Mg2+, Sr2+ and Fe3+ ions

Abstract

Analcime and clinoptilolite are among the most abundant zeolites in nature. During recent decades natural analcimes and clinoptilolites, also synthetic modified analcimes have been investigated as potential and innovative substances, possible to use for the immobilization of radioactive waste, molecular catalysis and other purposes. However, natural analcimes like many natural rocks are contamined with various impurities (about 30 %), which significally reduces their sorption possibilities and possibilities of their using in such chemical technologies as catalysis, fractioning of hydrocarbons and other. In this article the stability of cubic analcime at the hydrothermal conditions at 180 °C temperature in solutions of various concentrations, containing Li⁺, Mg²⁺, Sr²⁺ and Fe³⁺ ions has been examined. These processes have big signification for the formation of ion-exchanged analcimes, its sorption properties and also if ions have been immobilized in analcime structure. It has been established, that as result of interaction between cubic analcime and lithium chloride solutions the formation of new compounds: lithium silicate and silinaite occurs. At the same hydrothermal conditions the interaction between cubic analcime and chloride solutions, containing Sr²⁺, Mg²⁺ and Fe³⁺ ions pass without formation of new compounds, and only with interposition of these ions in the structure of cubic analcime.

DOI: http://dx.doi.org/10.5755/j01.ms.19.3.1496