PURPOSE: To obtain the zeolite excellent in hot water resistance by treating a zeolite with the SiO2-to-Al2O3 molar ratio specified in an aq. soln. contg. NH3 to reduce the Na content below a specified value and carrying out ion exchange using a Cs neutral salt.
CONSTITUTION: A zeolite with the SiO2-to-Al2O3 molar ratio controlled to at least 10 is treated in an aq. soln. contg. ammonia (e.g. ammonium chloride soln.) to reduce the Na content to ≤0.01 in the Na2O-to-Al2O3 molar ratio. The zeolite is then subjected to ion exchange using a Cs neutral salt (e.g. CsCl). As a result, a highly hot water-resistant zeolite having the oxide morality shown by the formula ((a) is 0.95-1.05, (b) ≤0.1, (c) ≥10, and (d) is an optional number). The obtained zeolite is appropriately used for the catalyst, adsorbing and separating agent, etc., to be used in a high-temp. environment contg. steam.
OKAZAKI SHUJI
SEKIZAWA KAZUHIKO
