Caracterização mineralógica da fração argila da mina Portobello, no município de Cedro de São João, Estado de Sergipe

Abstract

The Batinga Formation, Neo-carboniferous age, is predominantly composed of siltstones and argillites, which occur finely laminated, similar to varvites, sometimes irregular, but in gradations with cross stratification for sandstones and shales of the Member Boacica. These rocks are exploited for use in the ceramic industry, in the count of Cedro of São João, in the state of Sergipe, Brazil. The main objective of present work is to characterize, from the mineralogical point of view, the material extracted by company Mining Portobello Ltda for the manufacture of ceramic coating, through the method of X-ray diffraction. The samples were analyzed from the viewpoint of two different methodologies: powder and oriented methods. In the powdered sample seeking to preserve the disorientation of the particles where all the minerals or crystalline structures are analysed. The oriented sample (natural, glycolated and calcined) is composed by the fraction <2µm in thin blade, where in this process, the faces (001) are privileged for the identification of clayey minerals. The samples were analysed from the point of view of two methods: powder method and oriented method (natural, glycolated and calcined). The minerals identified in the samples in the clay fraction were: Chlorite, Ilite/Mica, Caulinite, Quartz, K-feldspar and Plagioclase. The mineralogy found corroborates the data presented by several researchers in the literature and, especially, emphasize the fact that the composition of this raw material has very good quality for the ceramic coating industry.