Because there are uniform small internal pores in the molecular sieve structure, Small block activated carbon Ganzhou When the molecular linear degree of reactants and products is close to the pore size of the crystal, the selectivity of catalytic reaction often depends on the corresponding size of the molecule and pore size. This selectivity is called shape selective catalysis. There are two mechanisms leading to shape selectivity. One is caused by the difference of diffusion coefficient of molecules participating in the reaction in the pore cavity, which is called mass transfer selectivity; The other is caused by the space limitation of the transition state of the catalytic reaction, which is called transition state selectivity. Molecular sieve has clear pore cavity distribution, extremely high internal surface area (600m2/s), good thermal stability (1000 ℃), and adjustable acid site center. The acidity of molecular sieve mainly comes from three coordinated aluminum atoms and aluminum ions (AlO)+on the framework and in the pores. The OH based acid sensitive site center on the molecular sieve HY obtained by ion exchange, and the aluminum ion outside the framework will strengthen the acid site, forming the L acid site center. Polyvalent cations such as Ca2+, Mg2+and La3+can show the acid site center after exchange. The reduction of transition metal ions such as Cu2+and Ag+can also form acid site centers. In general, the higher the Al/Si ratio, the higher the specific activity of OH group. The modification of zeolite acidity can introduce protons through direct exchange of dilute hydrochloric acid. Small block activated carbon major This method often leads to dealumination of molecular sieve framework. So NaY will become NH4Y and then HY.

Small block activated carbon major The addition of retention aids in the wet end of paper making is an important way to improve filler retention, which has been widely used in industrial production. Some studies reported that clinoptilolite (particle size 0.5-2 μ m) was used as a microparticle retention aid to compare the retention effect with silica and bentonite microparticle retention aid systems. The retention effect of clinoptilolite retention aid is equivalent to that of the silica microparticle retention aid system with the same dosage, which is far better than that of the bentonite microparticle retention aid system. And the use of zeolite as paper filler eliminates the need for additional microparticle retention aids. It is also reported that the retention rate of TiO2 nanoparticles can be significantly improved by using zeolite molecular sieves as retention aids in the preparation of photocatalytic paper. Compared with starch and cationic polymer, zeolite molecular sieve microparticle retention aids have better effects on improving the retention and drainage properties of paper stock and improving the uniformity of paper. Small block activated carbon major The use of zeolite particle retention aids can effectively avoid flocculation between fibers, and help to form fiber particle fiber flocculating particles. In addition, it can also support titanium dioxide nanoparticles.

The holes and channels inside the zeolite crystal are uniform and fixed in size, and the diameter of the holes is generally 6~15A. Small block activated carbon Ganzhou Only molecules with smaller diameter can enter the cavity through the zeolite channel and be adsorbed, while large molecules cannot enter the cavity and be adsorbed. Zeolite is also called molecular sieve because of its selective adsorption performance. However, silica gel, activated carbon and other adsorbents have no selective adsorption and screening performance due to their non uniformly fixed pore sizes and large changes. Shunyi zeolite filter material price. Because the silicon (aluminum) oxygen tetrahedron of natural zeolite crystal has many holes and channels, which occupy cations and water molecules. When some other goods are completely dehydrated after baking, the crystal skeleton is not damaged, but forms large holes on the inner surface, which can absorb and store a large number of molecules, so it has the characteristics of large adsorption capacity and high selectivity. Small block activated carbon major In different zeolite minerals, the proportion of silicon and aluminum is different, and the different proportion will cause some characteristics of zeolite changes, such as ion exchange and acid resistance.

Small block activated carbon major 1. From the composition of both, carbon molecular sieve is an excellent non-polar carbon material, while zeolite molecular sieve is a hydrate of crystalline aluminosilicate metal salt. The two are completely different in the periodic table of chemical elements! 2. With different pore sizes, the pore composition of zeolite molecular sieves is obviously registered, which can be generally divided into macropores, mesopores and micropores, and there are interconnections between the pores, while carbon molecular sieves are generally micropores! 3. The adsorption principle is different. Zeolite molecular sieves absorb molecules of certain size and repel molecules of larger substances. Small block activated carbon Ganzhou Carbon molecular sieve contains a large number of micropores, which can effectively separate the components of gas mixture. 4. The uses are also different. Carbon molecular sieves are widely used in coal fields, petroleum, chemicals, metal heat treatment, electronic manufacturing, food preservation and other industries, while zeolite molecular sieves can be used in addition to petroleum, chemicals, natural gas, electronic production, industrial gas separation, pharmaceutical industry, refrigeration industry, and hollow glass manufacturing.