显示标签为“mole sieve dehydration”的博文。显示所有博文
显示标签为“mole sieve dehydration”的博文。显示所有博文

2015年6月28日星期日

the Performance of zeolite 3a molecular sieve


Yu and 
zeolite 3a molecular sieve  metallic luster, hardness of 3~5, relative density is 2~2.8, colored with natural zeolite, synthetic zeolite is white, insoluble in water, thermal stability and resistance to acid increasing with the improved SiO2/Al2O3 ratio.mole sieve dehydration have very large surface areas, 300~1000m2/g, Crystal surface in highly polarized, is a kind of high efficiency adsorbent, also a solid, the surface has a high acid concentration and intensity, can cause the carbenium ion-catalyzed reactions.When the composition of the metal ion exchange with other ions in solution, you can adjust the aperture, change its adsorption and catalytic properties, which produce different molecular sieve catalysts.

2015年6月23日星期二

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.