Large crystals of mordenite and MFI zeolites

Synthesis conditions were investigated for various zeolites starting from coal mine wastes. Inorganic (NaOH) or organic (TPAOH) bases were used as reacting solutions, resulting in the preparation of zeolites with different structural types such as MFI, MOR, GIS, or ANA. The use of a ring separator in the Teflon-lined reactor allowed us to demonstrate the existence of two mechanisms, solid transformation and solution nucleation, and to prove that these mechanisms do not lead to the same structural type. Optimization of the synthesis parameters allowed us to grow large crystals (several hundreds of microns) of mordenite and MFI zeolite.