Mullite is used to obtain a refractory material, there are several factors that influence the synthesis process of mullite: the preparation of the mixture, the precipitation and the reaction of SiO2 and Al2O3. For the synthesis of mullite, samples of kaolin processing residues were used as precursor material, because it presents SiO2 and Al2O3 in its composition. This work aimed to identify, by X-ray diffraction, and quantify the mineral phases present in samples of kaolin processing residues from the Amazon region calcined at 1300, 1400 and 1500 ºC, using the Rietveld method. The method allowed the refinement of the complex crystalline structures and was applied to the data supply for quantitative analyses with satisfactory results of good accuracy. The results of the quantification of crystalline and non-crystalline phases (with internal standard) in the samples calcined at 1500 ºC presented approximate values of mullite (62%), cristobalite (32%) and non-crystalline phases (6%), for both samples, indicating that the refinement model applied is optimal. These results obtained from the quantification of the phases by the method of Rietveld are presenting coherent and satisfactory values, in comparison with the theoretical ones by the phase diagram Al2O3 and SiO2.

Molecular dynamics techniques are increasingly being used for material science studies, being a theoretical approach based on molecular mechanics studies. GROMACS is a free software that allows the development of simulations of various types of molecules, from biological molecules to inorganic structures associated with the area of materials, requiring the system parameterization according to the force fields used in the simulation. ClayFF is a force field used for crystalline clay structures and has been applied in several articles published in scientific journals. The objective of this work was to present a didactic approach to the implementation of ClayFF in GROMACS and the force field was used to simulate a kaolinite structure as an example, demonstrating the implementation for students and researchers in the field.