Principles and types of Zeolite

Absorption features: molecular sieve adsorption material from physical adsorption (van der Waals forces), which has a strong internal crystal cavities polarity and Coulomb field of polar molecules (such as water) and unsaturated molecules show a strong adsorption capacity.
Screening function: very uniform pore size distribution of the molecular sieve, only molecular diameter smaller than the diameter of the hole before substance may enter bughole internal molecular sieves.
By order of priority and size to distinguish molecular adsorption of different substances, so the image is called "molecular sieve."
Type: synthetic zeolite molecular sieve zeolite and two natural. Most ① natural zeolite formed by volcanic tuffs occur and tuffaceous sedimentary rocks in marine or lacustrine environment reaction. Have been found to have more than 1000 kinds of zeolite mineral, the more important ones are 35 kinds, often with clinoptilolite, mordenite, erionite and chabazite, etc. Mainly in the United States, Japan, France and other countries, China also found that a large number of mordenite and clinoptilolite deposits, Japan is the largest country in the natural zeolite mined. ② due to natural zeolite subject to resource constraints, from the beginning of the 1950s, a large number of synthetic zeolites.
Goods zeolite crystal structure common prefixes Digital classify the different molecular sieves, such as type 3A, 4A type, 5a zeolite molecular sieves. 4A Class A type that table, aperture 4Å ;. A type of zeolite containing Na +, referred to as Na-A, if one is Na + K + replacement, pore size of about 3Å ;, is the 3A molecular sieve; Na-A if there is more than one third of the Na + Ca2 + exchange, aperture is about 5Å ;, is the 5A molecular sieve.