Molecular sieves are a class of adsorbents or thin-film materials with uniform micropores, mainly composed of silicon, aluminum, oxygen and some other metal cations. Their pore sizes are equivalent to the general molecular size, and various fluid molecules are screened according to their effective pore sizes. Zeolite molecular sieves are those natural and synthetic crystalline aluminosilicates having molecular sieve action. Zeolite molecular sieve has become an independent discipline due to its unique structure and properties. The application of zeolite molecular sieve has spread to petrochemical, environmental protection, bioengineering, food industry, pharmaceutical and chemical industries. With the development of various industries in the national economy, the application prospect of zeolite molecular sieves is increasingly broad.
Zeolite molecular sieve crystals have many excellent properties such as adsorption and exchangeability, so they are widely used in petrochemical industry, detergent industry, fine chemical industry and other industries. In the study of zeolite molecular sieves, the preparation of molecular sieves and their functionality from inexpensive natural minerals is one of the most valuable studies in this field. The smectite belongs to the group of pyrites and is one of the mineral species. The smectite is based on the aqueous framework of aluminosilicate. It has selective adsorption to various cations under different temperature conditions and has good catalytic function. It has processability, low hardness, low thermal expansion and good thermal stability. It is widely used in environmental materials, agricultural and livestock improvement, chemical additives and adsorbents.