[en] The mullite is an extremely important mineral for the field of ceramic applications because of its excellent physical, chemical, thermal and mechanical properties. As this material is rare in nature, many studies focus on the synthesis of the same through processes that are economically viable. One of the methods used for obtaining mullite consists in heating at high temperatures mixing sources of silica with alumina, such as aluminosilicates that are often used for this purpose. The aims of this study is to obtain mullite from compositions containing kaolin and alumina with different particle sizes. Initially the precursors were subjected to chemical, particle size and mineralogical characterization. The alumina has undergone a process of grinding for 15, 45 and 60 minutes. After formulation of the masses, the specimens were pressed and sintered at temperatures of 1200, 1300 and 1400 ° C, with a heating rate of 5 ° C / min and 60 minutes of residence time. Subsequently, the samples were subjected to physical and mechanical characterizations: linear shrinkage, apparent porosity, water absorption, apparent density flexural strength at three points. The results show the influence of granulometric distribution on the kinetics of reactions and the best results were observed for the mass containing kaolin and alumina subjected to milling for 45 minutes. (author)