The effects of temperature and duration of thermochemical treatment in a sodium silicate solution of metakaolin; a mechanical mixture containing 60 wt % mordenite, 30 wt % metakaolin, and 10 wt % fumed silica; and granules of the same composition on the mass transfer between the liquid and solid phases of the reaction mixture have been studied. The main steps of the formation of high-crystallinity granular mordenite with a hierarchical pore structure have been established.