Crystalline silicon-rich (metallo) silicates of the sodalite type and process for preparing such (metallo)silicates

摘要

Crystalline silicon-rich (metallo)silicates of the sodalite type having in the as-synthesized form a molar composition expressed by the formula:(0-0.025)M_2/n0.(0-0.025)X₂O₃.SiO₂.(0.01-0.2) trioxane.(0-5.0)H₂Owherein M is an alkali or alkaline earth metal ion having a valency n and X is at least one of Al, Fe or Ga and can be prepared from an aqueous mixture comprising a source of silicon, optionally a source of at least one of aluminium, iron or gallium, a source of alkali or alkaline earth metal and trioxane at elevated temperature until a crystalline sodalite is formed which is subsequently separated from the mother liquor and dried, and which may subsequently be calcined.