This work has for objective to characterize the so-called "clay fraction", i.e., that fraction with particle size < 2 µm, and to evaluate by dilatometry, thermogravimetric and differential thermal analysis, and X-Ray diffraction, its effect on the firing behavior of a sedimentary kaolinitic clay. The "clay fraction" sample was obtained by the sedimentation technique based on the Stokes law and submitted for mineralogical, chemical and morphological characterization by X-Ray diffraction, X-Ray fluorescence and transmission electron microscopy. The results showed that the clay's granulometric fraction with size < 2 µm displays a mineralogical composition formed by kaolinite, haloisite, micaceous mineral, goethite and gibbsite. During the firing, this "clay fraction" is the main responsible for the sintering of the clay body.
clay; characterization; particle size; mineralogy; firing