Characterization of Brazilian Northeastern plastic clays

Abstract

Plastic clays are one of the main raw materials used in ceramic technology. However, there is a shortage of good quality plastic clays in the world for use in porcelain technology. The aim of this study was to characterize plastic clays from Northeastern Brazil. Chemical and mineralogical composition, particle size distribution, plasticity and green strength of the clays were determined. The analyzed clays were predominantly composed of kaolinite and quartz, and some contained smectite. The amount of iron oxide in the clays was higher than 1.0% and for some of them the values were higher than 3%; the liquid and plastic limits ranged from 22% to 48% and 10% to 32%, respectively. According to characterization data, three plastic clays had potential to be used as alternative ball clay, due to their plasticity and mineralogical characteristics.

Development of a New Clay-Based Aerogel Composite from Ball Clay from Piauí, Brazil and Polysaccharides

“…The thermogravimetric curves in a non-oxidative atmosphere are represented in Figure 7, and the results are summarized in Table 4. The thermal behavior of the clay is similar to that reported in previous studies [15,18]. Figure 7a presents the TGA curve of clay, which presents two events.…”

“…Ball clay, also called plastic clay, is defined as a type of sedimentary clay with fine grain size, high plasticity, and lower refractoriness that contains kaolinite and has strong binding properties [15,16]. These clays have been widely used in agriculture, the ceramic industry, and as suspension agents or binders in several industries but have rarely been used in the production of aerogel.…”