Abstract
Various kinds of zeolite rocks have been found in Japan, occurring in nature and covering a wide area. Since these rocks are known to have generally high ability to adsorb cations and water, they may be used as a sort of soil improver.
The present writers obtained the zeolite content by measuring the cation adsorptive capacity of the zeolite rock specimens. Selected as the specimens for this study are the rocks specially abounding in clinoptilolite or mordenite as revealed by the results of X-ray diffraction, chemical and thermal analyses.
In a certain zeolite rock, relatively smaller cations are adsorbed inside the pores (smaller than about 4 Å) which are not large enough for larger cations to enter. Based on the above assumption, the writers worked on seven specimens in which ammonium ions were adsorbed beforehand to a saturated extent, and calculated the quantities that cannot be exchanged by relatively larger cations (tetrabutyl ammonium ions). The values thus obtained were compared with the values calculated from an ideal chemical formula of zeolite, and the content of zeolite was determined.
The result has led to a conclusion that the zeolite content in the examined seven specimens of zeolite rocks range from 37.5% to 85%.
