Abstract: Aluminum can be removed from tetrahedral framework sites of zeolite frameworks and substituted with elements such as silicon, gallium, titanium or zirconium. The process involves three steps:(a) forming a mixture of the ammonium or alkaline metal form of the zeolite in the hydrated state and a crystalline ammonium fluoro-halo-metallate salt;(b) heating the mixture at elevated temperatures to remove the aluminum from the zeolite and to introduce the metal from the salt into the structure of the zeolitic component by solid-state reaction while forming a fluoro-halo-aluminate complex salt; and(c) removing the formed fluoro-halo-aluminate complex salt.