the Type of Synthesis of zeolite and natural zeolite molecular sieve

Synthesis of zeolite and molecular sieve zeolite in two ways.① the most natural zeolite by volcanic Tuff and tuffaceous sedimentary rocks in marine or lacustrine environment reacts to form.Have been found to have more than 1000 kinds of zeolite minerals, more important has 35 species, common clinoptilolite, mordenite zeolite, Mao Feishi and diamond, etc.Mainly in the United States, Japan, France and other countries, China has a number of mordenite and clinoptilolite zeolite deposit, Japan is the biggest national exploitation of natural zeolite.② resource constraints and by natural zeolite, in the 1950 of the 20th century, the extensive use of zeolite synthesis (see table).

Commodities commonly used prefixes digital crystal structure different mole sieve dehydration  re classified, such as 3A, 4 a, 5 a molecular sieves.In table 4 type a is a class aperture 4Å.Recorded as a molecular sieve containing Na+ Na-A if Na+ K+ replacement, Aperture is approximately 3Å, Which is 3 a molecular sieve;1/3 Na+ over Na-A Ca2+ replacement, Aperture is approximately 5Å, Which is 5 a molecular sieves.

the definition of Molecular sieve

Magnitude, it only allows a diameter smaller than the diameter of the molecules into, so molecular sieve zeolite in the mixture can be screened by size.It is called molecular sieve.Back more than 200 years ago, b.Kelongshitaite first named aluminosilicate zeolites, chemistry formula for m and n are metal ions and Valence;Number of molecule x is silicon dioxide;Y is the number of water molecules;P is the atomic number of aluminum;Q is the number of silicon atoms.molecular sieve dehydration process in the chemical industry as a solid adsorbent material desorption of adsorbed by the molecular sieve can be recycled after use.Also used for gas and liquid drying, purification, separation and recycling.Starting in the 1960 of the 20th century, used as a catalyst in the petroleum refining industry, has now developed a variety suitable for different molecular sieve catalysts for catalytic processes.