Análise e comparação das características de argilas utilizadas por diferentes olarias na produção de tijolos tradicionais.

Abstract

This work presents the comparative characterization of two clays used by ceramic industries in the municipality of Iranduba (AM) for the production of ceramic bricks. The samples were analyzed by X-ray Fluorescence (XRF), X-ray Diffraction (XRD), liquid and plastic limits, linear shrinkage, and flexural strength. The chemical results showed similar compositions between the clays, with predominance of SiO₂ and Al₂O₃. The mineralogical analysis indicated the presence of quartz and partially disordered kaolinite. The Liquid Limit values of both clays were similar, around 64%, while the Plastic Limit revealed higher plasticity for clay B compared to clay A. Linear shrinkage values were low, ranging from 0.31% to 0.48%, indicating good dimensional stability after firing. Flexural strength tests showed average values close to 3 MPa, consistent with the standard requirements. After firing, clay B presented a slightly darker coloration than clay A, a difference attributed to its slightly higher Fe₂O₃ content. Overall, both clays are suitable for ceramic production; however, clay A demonstrated greater uniformity and dimensional stability, while clay B showed higher plasticity and greater sensitivity to processing.