The Al incorporation on SBA-15 type material and the effects of pH adjusting and presence of NaF were studied. The direct synthesis method was performed for comparison. The following parameters were evaluated: the Si/Al ratio, pH increase, and amount of NaF added. These parameters have a great influence on the synthesis of the mesoporous Al/SBA-15 type, but the pH the most influential parameter for the incorporation of Al into the SBA-15 structure. The formation of the SBA-15 structure was observed through the direct synthesis method. However, aluminum is not present in the material. The increase in pH contributed to the formation of a disorganized material. By EDX, it was observed that synthesis with a Si/Al = 5 ratio and pH approximately 4 provides materials containing aluminum. When the amount of aluminum during the synthesis is lower, a pH of approximately 8 is required to incorporate aluminum into the final material. The Al-NMR analysis showed that it was possible to insert aluminum in the structure of SBA-15, but with the presence of aluminum hexa and pentacoordinated. In the catalytic test of the dehydration reaction of ethanol, the samples with higher aluminum contents showed better catalytic performance due to its higher acidity.

The NaOH/metakaolin ratio and crystallization time were studied for the synthesis of zeolite NaA from a sample of kaolin from a Capim mine. The tests were carried out by using statistical design with axial points and replication of the central point. The samples obtained were characterized by X-ray diffraction (DRX), scanning electron microscopy and chemical analysis using a microprobe EPMA. The results showed that there is a relationship between the amount of NaOH added and crystallization time. The tests carried out using the lowest NaOH/metakaolin ratio (0.5) and the shortest time (4 h) produced a non-crystalline material. On the other hand, increasing the NaOH/metakaolin ratio and the crystallization time led to the formation of a NaA phase with a high structural level, but with the presence of a sodalite phase as an impurity.

Montmorillonite clays are of great interest for industrial processes such as catalysis and adsorption. The textural properties of clays can be modified in an attempt to increase their uses. This paper describes the acid treatment of natural montmorillonite clay. The materials were characterized using X-ray diffraction (XRD), atomic absorption spectroscopy (AA) and BET surface area measurements. Three different acids (HCl, HNO3 and H2SO4) were tested, and HCl and H2SO4 were more efficient for removing Fe from the clay. The results indicate that HCl better preserves the material structure because less Al is removed. A central composite design (CCD) 2² was applied to evaluate the treatment using HCl. The temperature and concentration presented positive effects on the removal of Fe, Al and Mg. Combinations of the HCl acid solution concentration and temperature, such as 4 mol.L-1/50 °C and 1 mol.L-1/75 °C, assured that Fe was removed with less damage to the structure.

Zeolite A was synthesized using the coal ash from Siderópolis/RS - Brazil. The synthesis was based on a standard IZA synthesis using coal ash as the Si and Al source. XRF analysis showed that the coal ash has a Si/Al ratio of 1.52, which is close to the Si/Al ratio required to produce zeolite A (1.0). The synthesized materials were analyzed by XRD, SEM and N2 adsorption. More crystalline materials were obtained during synthesis when an additional treatment was applied at a temperature of 353 K at the dissolution of NaOH step. The product formed after 4 hours was the most crystalline, but even the product formed after 1 hour proved to be better than that formed using the standard 4 hours IZA synthesis. The zeolites synthesized by this method had an adsorption capacity of 120 mg.g-1 for Ca2+, half the capacity of commercial zeolite A (300 mg.g-1). It was not possible to obtain blue or green pigments using the synthesized zeolite A.