Physical-chemical, mineralogical and technological characterization of clays of Caxias/MA

Abstract

This paper aims to characterize a mixture of clays used in the manufacture of bricks in the region of Caxias/MA. Chemical composition, X-ray diffraction, thermal analysis (TG/DTG), granulometric analysis and plasticity were performed. In addition, technological properties such as water absorption, apparent porosity, bulk density and flexural strength were determined. The specimens (15x2.5x1.5 cm) were shaped by extrusion and fired at three temperatures, 800, 900 and 1000°C. In terms of mineralogy, the samples are kaolinitic and illitic clays. The results showed that the formulation studied is suitable for the manufacture of masonry bricks. Hence, the clay samples have potential for several applications (bricks, tiles, among others) as raw material for the red ceramic industry in the state of Maranhão.