Efeito do tempo de síntese de zeólita A a partir de caulim amazônico, conformação por extrusão e verificação desta na eficiência de adsorção de NH4 +

Abstract

Kaolin is widely used in the field of materials (ceramics, pozzolans, fillers and manufacture of paints) as much as the waste and the product received. Currently the most exploited use has been in zeolite synthesis, as it presents the most noble applications. Zeolites are synthesized from silicon and aluminum sources, a fact that justifies the use of kaolin, because it is formed essentially by the clay mineral kaolinite (Al2Si2O5 (OH) 4). In this work we made a kaolin comparison of Grass River region with kaolin mineralogical / chemical and other Amazon kaolin reference to see if you can make it a reference material. The comparison was carried out by size analysis, X-ray diffraction, X-ray fluorescence, scanning electron microscopy, differential thermal analysis and infrared spectroscopy and crystallinity calculations. Moreover, the kaolin of the Rio Capim region was used as a source of silicon and aluminum to obtain the zeolite in order to determine the effect of time on the synthesis. Assays were performed in a time of 30 min, 1 h, 2 h and 24 h applied in these zeolites ammonia adsorption. From the synthesized zeolite was carried out the forming process by extrusion, evaluating various ligands (sodium silicate, bentonite, kaolin and CMC) and firing temperatures (500, 700 and 800 ° C). Later, these were extruded applied also in ammonium adsorption to check its efficiency. It was observed that it is possible to use kaolin Grass River as mineralogical reference material (high degree of structural order) and/or chemical, because it showed performance equal or close to the reference kaolin compared in this work. The zeolite A was synthesized from Amazon kaolin and this presented an excellent silicon and aluminum source. All synthesis times gave zeolite A zeolite in amounts of ~ 600 g. All zeolites showed a high degree of structural view to XRD and SEM. It was also found that synthetic zeolite A in 30 minutes time can be performed without loss in its application, since it presented below only 3% difference in adsorption efficiency compared to 24 h. The shaping by extrusion tests proved promising, 5 out of 10 trials were successful in obtaining granulated with physical strength. However, only the granules containing sodium silicate and CMC as a binder showed a high ammonia adsorption efficiency. With values of ~ 95,5% efficiency in 24 hours of contact.