Study On Properties Of Sepiolite As Carrier Of Catalyzer

Sepiolite is a kind of Mg-riched silicate clay mineral of fibrous structure. It is also one kind of mineral product which has been used most widely in recent years and been developed in diffirent fields most rapidly.The work to develop nature clay minerals as novel catalyzer carrier has been paid great attention. The resource of the sepiolite in China is rich, thus, the developing it as catalyzer materials possess not only research value but also real economic meanings. However, as far as the surface of nature sepiolite is concerned, its acidity is weak, and the channel is narrow, and its thermo-stability is poor, which lead to defects such as the destroying effect on the component structure of molecular sieve on the condition of water steam. Therefore, to modify the properties of nature sepiolite is very necessary if the material will be used as catalyzer carrier.The present research discussed the properties of sepiolite as catalyzer carrier on the basic of its catalyzing characteristics. Due to the potential large specific surface area of sepiolite, its catalyzing activity was directly proportional to specific surface area. Thus, the properties of sepiolite as catalyzer carrier could be determined by increasing the specific surface area inside or outside the sepiolite.In present work, the sepiolite minerals were high-crystallinity selected, impurity removed, acid-activation treated and thermo-activation treated to increase the specific surface area and activation center, so as to satisfy the demand for catalyzer carrier. The type of sepioloite mineral suitable for the catalyzer carrier was also summarized. Systemic and detailed research had been (tone, and the following satisfying result was obtained.1. By means of the refining and purifying of sepiolite minerals, portions with low- crystallinity and impurity minerals which was not fit for being the catalyzer carrier were eliminated. The specific surface area of the refined sepiolite product increased to 236.36m2/g from the original 139.66m2/g.2. By activation-treating sepiolite with acid modifying, the channel between crystals, the porosity and the structure changed distinctly, and the specific surface area increased to 295.39 m2/g from 236.26 m2/g.3. By thermo-activation treating, the crystal water and constitution water of sepiolite were further changed. Changes of channels between crystals and porosity made the specific surface area of the products increase from 295.39 m2/g to 324.67m2/g.4. By damping, mixing and molding, the carrier produced possessed the specific surface area of 319.59 m2/g, which was fit for the catalyzer carrier.5. The specific surface area of precipitation type of sepiolite (short fibrous structure) increased only from 65.61 m2/g to 98.57 m2/g. This means that this type was not the suitable catalyzer carrier candidate.Systemic study had been done in this work on the high- crystallinity selecting, impurity removing, acid-activation treating and memo-activation treating of the sepiolite mineral. The specific surface area and activation center of the sepiolite were increased greatly, whichendowed the materials with properties as catalyzer earrier. In addition, due to the largely improvement of the main properties of sepiolite such as adsorption properties and catalyzing properties, this novel type of sepiolite would achieve wider application in the field of industry, agriculture, environment protection and so on.