Sintering Behavior of Kaolin with Calcite

The study of sintering behavior of clay raw materials might be difficult because, as it is well known, these clays have a complex mineralogical composition, which causes a series of phase transformations occurring during sintering. Those processes relate to major and minor clay minerals (such as phyllosilicates, quartz, calcite, dolomite and hematite). Kaolinite is one of the main components of the clay. In this work, we consider sintering of kaolin, with different addition of pure calcite. The following techniques were used: differential thermal analysis (DTA), thermogravimetry (TG/DTG), dilatometry (DIL), heating microscope probe and X-ray diffraction (XRD), and scanning electron microscopy (SEM). In addition, comparisons between the microstructure of the sintered bodies and their physical- mechanical properties have been made.