Potencialidade de diferentes jazidas de argila da região central do Estado de Roraima para a produção de cerâmica vermelha

Abstract

The State of Roraima has a wide diversity of soils with varied textures, among them the clayey, occurring in areas that are significantly advantageous, regarding the availability, with great potential of exploration and heterogeneous constitution, besides, the State also possesses a quantity appreciable of ceramic industries that refers to the search for new deposits that meet the demands of the ceramic industries of the State. Thus, this work aims to evaluate the potentiality of residual and sedimentary clays for their use in the processing of red ceramic materials. Four areas were selected for this study, two of which were composed of sedimentary clays (VM and CA) and two by residual clays (AA and MC). The raw materials were benefited and characterized by physical tests (particle size analysis, specific mass and Atterberg boundaries), X-ray fluorescence spectrophotometry and X-ray diffraction. Ceramic specimens with dimensions of 60x20x7mm, burned at 850, 900 and 950ºC were made and physical-mechanical determinations (linear retraction, water absorption and bending rupture stress) were carried out. The results showed that they are mainly composed of SiO2, Al2O3, Fe2O3 and kaolinite (K) as the main clay form, with no expansive argillomineral peaks. The CPs made with sedimentary clays (VM and CA) are initially acceptable as raw material in the red ceramic industry, both for tiles and blocks. The water absorption variable indicates that only the CA sample, collected in the Rio Branco floodplain in the municipality of Cantá, is classified as a satisfactory raw material for the manufacture of ceramic blocks and tiles.