Industrial Kaolin Waste as Raw Material in the Synthesis of the SAPO-34 Molecular Sieve
Darllan do Rosário Pinheiro, Leonardo Rodrigues Gonçalves, Raimunda Lina Pacheco de Sena, Marlice Cruz Martelli, Roberto de Freitas Neves, Nielson Fernando da Paixão Ribeiro
Abstract
High-purity SAPO-34 was synthesized using industrial kaolin waste produced in the Amazon region as the main source of silicon and aluminium. The hydrothermal method was applied to investigate the effect of the Si/Al ratio and crystallization time on the phase formation and purity. The materials were characterized by X-ray fluorescence, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy, which demonstrated that SAPO-34 with greater purity was obtained only for the composition whose Si/Al ratio was approximately 1, which was obtained by inserting Al2O3 into the synthesis gel.