Characterization of clays from the Corumbataí formation used as raw material for ceramic industry in the Santa Gertrudes district, São Paulo, Brazil

Abstract

a b s t r a c tThe Ceramic District of Santa Gertrudes (CDSG) is the largest producer of ceramic floor and wall tiles in Brazil. Tile manufacturers in the CDSG use the single raw material, clayey rocks from the Corumbataí formation. Mineralogical, chemical, thermal and microstructural characterization of the clayey rocks from the Corumbataí formation have been performed in order to better understand effect of the studied properties on dry route tilemaking process. The results revealed different compositional features among the studied clayey raw materials. The bulk samples were dominated by clay minerals associated with quartz, feldspars and minor amount of hematite. All samples were complex mixtures where different types of clay minerals (illite, smectite, illite-smectite, kaolinite-smectite, chlorite, sometimes kaolinite) coexist in variable amount. The amount of clay minerals increased with a higher degree of weathering of studied samples. Different technological behavior was expected for studied raw materials due to their heterogeneous nature, in terms of mineral composition and weathering degree. To improve technological behavior of studied materials during tilemaking process an upgrade of the currently used raw materials preparation is recommended (raw materials maturation, more aggressive milling of raw materials, addition of plastic component and homogeneous mixing of plastic and non-plastic components).

Properties and characterization of a clay raw material from Miličinica (Serbia) for use in the ceramic industry

“…The presence of clay minerals was confirmed in all samples by the absorption bands between 3700 and 3620 cm −1 , assigned to stretching vibrations of the OH groups of clay minerals. The shoulder near 3683 cm −1 represents kaolinite OH-stretching vibrations and the relative intensity of this band is indicative of the kaolinite abundance in the samples (Madejová et al, 2002;Madejová, 2003;de Almeida Azzi et al, 2016). According to the relative intensity of this band, the abundance of kaolinite decreases in the following order: M1 > M3 > M2, in agreement with the semiquantitative estimations with XRD.…”

Characterization and purification of Algerian natural bentonite for pharmaceutical and cosmetic applications

“…4 and in Fig. 5 .The infrared spectra show the presence of stretching vibrations at 3618 cm −1 for structural OH groups present in the samples of clay minerals (i.e., illite, smectite, interstratified clay minerals, kaolinite and chlorite) [ 35 ]. The band near 3406 cm −1 is assigned to the OH stretches of water [ 36 ].…”

Characterization and use of clays and argillites from the south of Santa Catarina State, Brazil, for the manufacture of clay ceramics

“…The thermal decomposition in the temperature range of 300–800°C is due mainly to the dehydroxylation (release of OH structural groups) of clay minerals (Escalera et al , 2014; de Almeida Azzi et al , 2016). In this temperature range, three events occur, starting with the second endothermic event between 300°C and 500°C, related to the amount of crystalline water and showing greater loss of mass due to kaolinite dehydroxylation.…”