The basic definition of zeolite molecular sieves

3a molecular sieves is crystallization of aluminum silicate metal salt hydrate, its chemical general formula is: Mx/m [(AlO2), x (SiO2), y] zH2O. M on behalf of the cation, M said its valence number, z said water hydration, x and y are integer. molecular sieve siliporite is activated, the water molecules are removed, the rest of the atoms form cage structure, aperture is 3 ~ 10 & Aring; . Crystals have many size of zeolites hole, hole there are many between the diameter of the hole (also called "window"). Because of the molecular sieve can be smaller than the aperture molecular adsorption into the hole, and to exclude is larger than the aperture of the molecules in the hole, have the effect of molecular sieving, so named molecular sieve. Zeolite molecular sieve can exist in the nature, artificial synthesis from the 1970 s.