Characterization of new Occurrences of Clays in the City of Pedra Lavrada-PB, for Use as Ceramics Raw Materials

摘要

Paraiba State is a major instance of non-metallic mineral mainly of bentonite clay, balls clays, kaolin, feldspar, quartz, limestone, mica, etc. Recently it was discovered new deposits of clay in the region of Cubati and Pedra Lavrada, PB, thereby providing an expansion of mineral inputs in the region. The aim of thi study is to characterize the clays from the city of Pedra Lavrada - PB, to be used as ceramic raw materials. The mineralogy of the clays was performed using the following techniques: laser diffraction (AG), thermogravimetric and differential thermal analysis (TG and DTA), chemical analysis (EDX), X-ray diffraction (XRD), cations exchange capacity (CEC) and surface area (AE). The specimens were molded by compression of 2 MPa, with dimensions of 60mm×20 mm× 4 mm. The followed physical and mechanical properties were determined: firing shrinkage, water absorption, bending stress rupture and modulus after calcined at 800, 900, 1000, 1100 and 1200 °C. The results showed that the clays present smectite and kaolinite in their mineralogical composition and through the physical and mechanical properties this clays could probably be used as ceramic raw materials.