4A, 13X, Y, and other commonly used type mordenite molecular sieve preparation
4A, 13X, Y, mordenite and other commonly used molecular sieve preparation
4A molecular sieve: under the condition of excess NaOH, the sodium silicate and sodium aluminate were mixed at a temperature above 300C for 30 minutes. Again in the picture keyword static crystallization 6 hours, and then filtered, washed with water to the key words, and finally in the 1000C drying, that is, 4A molecular sieve material.
13X molecular sieve: similar to that of 4A zeolite, the mixture of sodium silicate and sodium hydroxide was stirred for half an hour in 750C to form a gel. Then in the 800C static for two days of crystallization, after filtration, washing to the picture keywords, and finally in the 1000C drying, that is, 13X raw materials.
Y type molecular sieve: in the plastic tank, into the quantitative concentration of qualified water glass, in the stirring, the sodium aluminate solution and sodium hydroxide solution into the mixture. At this point, the ratio of silica to alumina and the amount of alkali must be kept, so as to obtain Y zeolite. The gelation process should be stirred at room temperature for 2 hours. After gelation, the hydrothermal reaction is about 14 hours, which is the crystallization process of 1000C. After crystallization will pour out liquid, the remaining solids through washing, filtering and drying to obtain the Y type molecular sieve material.
Mordenite: monoclinic crystal, silicon aluminum ratio of 10-13 molecular sieve. Mordenite has a very high performance acid soak for several hours, the structure is still intact in concentrated hydrochloric acid, nitric acid, sulfuric acid, so called acid mordenite molecular sieve. Its thermal stability is also very high, such as in the 10000C high temperature will appear when the structural damage, and A, X and Y zeolite in 9200C has been destroyed. Synthesis of mordenite should be feed ratio control in Na2O: Al2O3: SiO2: H2O=1.8: 1: 13.8: 150, the crystallization temperature is about 2500C, the crystallization of 30 hours, the pH value of the solution was 10-11.