Two step process for the preparation of zeolite A by hydrothermal treatment of heulandite

摘要

A two step hydrothermal process for the preparation of a sodium cation form of zeolite A from heulandite by (1) heat treating a mixture of heulandite in an aqueous solution of sodium hydroxide and filtering the mixture followed by (2) reacting the filtrate with at least 75 percent of a stoichiometric amount of sodium aluminate to form and precipitate zeolite A from solution and recovering zeolite A.