GEOCHEMICAL STABILITY OF NATURAL ZEOLITES

Abstract

Zeolites are used in numerous agricultural, commercial, and environmental applications (e.g. as soil conditioners and fertilizers, and as adsorbents for ammonia, heavy metals, nuclear and organic wastes). It is important to understand their stability to insure their persistence and effectiveness in these applications. An analysis of the occurrence of natural zeolites provides basic data on conditions favorable for zeolite stability and formation. All such environments have neutral to alkaline waters and, with few exceptions, are associated with low-temperature (<300°C) alteration of highly reactive volcanic rocks containing natural glasses. The principal exceptions are certain deep sedimentary sequences, sometimes associated with petroleum...