Occurrence and Synthesis of Soil Zeolites

Abstract

Abstract Analcime has been identified by X‐ray diffraction analysis in a number of strongly alkaline soils developed from granitic alluvium in the San Joaquin Valley, California. Analcime occurrence is restricted to soils containing Na 2 CO 3 and with pH above 9. The analcime is generally concentrated near the soil surface and is most abundant in fine silt (5 to 2µ) and coarse clay (2 to 0.2µ) fractions. The occurrence and distribution of the analcime support the conclusion that it is of pedogenic origin. Cation exchange data indicate that the analcime Na is slowly replaced by NH 4 and that divalent cations Ca and Ba, as compared with K and NH 4 , replace relatively little of the analcime Na. Analcime was effectively destroyed in a soil by treatment with 0.5 N HCl. The mineral was readily synthesized in the acid‐treated soil and in the acid extract from the soil by titration of the systems to pH 9 and above with NaOH followed by digestion at 95C for 14 days.