Also known as synthetic zeolite or molecular sieve, the chemical composition of the general formula:
[M2 (I) M (II)] O.Al2O3.nSiO2. MH2O
In the formula, M2 (I) and M (II) are monovalent and divalent metal ions, respectively, most of which are sodium and calcium. The ratio of Si to Al is called zeolite. Silicon mainly comes from sodium silicate and silica gel. In the sodium aluminate and Al (HO) 3, etc., with sodium hydroxide aqueous solution of the colloidal reaction, after drying into zeolite, the general n = 2-10, m = 0-9.
Zeolite is characterized by the role of molecular sieves, it has a uniform pore size, such as 3A0, 4A0, 5A0, 10A pores. 4A0 zeolite 4A0 pore size adsorption of methane, ethane, but not more than three carbon adsorption n-alkane. It has been widely used for gas adsorption separation, gas and liquid drying and n-iso-paraffin separation.