CRYSTALLINE SILICON-RICH (METALLO)SILICATES OF THE SODALITE TYPE AND PROCESS FOR PREPARING SUCH (METALLO)SILICATES

摘要

Crystalline silicon-rich (metallo)silicates of thesodalite type having in the as-synthesized form a molarcomposition expressed by the formula:(0-0.025)M2/n0.(0-0.025)X2O3-SiO2-(0.01-0.2)trioxane.(0-5.0)H2Owherein M is an alkali or alkaline earth metal ionhaving a valency n and X is at least one of Al, Fe orGa and can be prepared from an aqueous mixturecomprising a source of silicon, optionally a source ofat least one of aluminium, iron or gallium, a source ofalkali or alkaline earth metal and trioxane at elevatedtemperature until a crystalline sodalite is formedwhich is subsequently separated from the mother liquorand dried, and which may subsequently be calcined.