Síntese e caracterização de peneira molecular tipo MCM-41 utilizando o rejeito do beneficiamento de quartzo como fonte alternativa de sílica.

Abstract

Molecular sieves are materials having pores which present interesting characteristics, such as high surface area, ordered pores and high thermal stability, which allow these materials are employed in many industrial processes. Among these zeolites materials are among the first to be discovered and used, with pores with diameters up to 0.8 nm. Because the diameter of its pore zeolites have limited use, being ineffective when used in reactions with the higher molecular weight molecules because they do not have access to their active sites. Thus, several studies aimed at the development of materials consisting of larger pores and to provide the same characteristics of zeolites, which led to the development by researchers at Mobil Oil of materials with mesoporous called M41S family, where the MCM-41 posting as the most important member, due to its characteristics. In recent times there has been increasing interest in reducing the costs of their synthesis, mainly by replacing more usais silica sources that have high costs for alternative sources. In this work the mesoporous sieve MCM-41 was synthesized using an alternative source of silica quartz tailing processing, using the hydrothermal method at 100 ° C for 5 days, and subjected to calcination at 500 ° C for 2 hours under nitrogen atmosphere and air. The material was characterized by X-ray diffraction (XRD), thermal analysis (TG/DTG) and spectroscopy in the infrared (FTIR). The analysis shows that the synthesized material presented hexagonal structure characteristic of mesoporous materials, proving that the alternative silica source was suitable for synthesis.