Composition and Technological Properties of Clays for Structural Ceramics in Limpopo (South Africa)

Abstract

This study evaluated the potential of raw clays from the Mukondeni region for structural ceramics and pottery based on traditional firing techniques. Physical properties were identified by particle size distribution, consistency limits, and clay activity. Mineralogical and chemical properties were investigated by X-ray diffraction (XRD) and X-ray fluorescence (XRF). Extruded clay bodies were fired at 900 °C. Technological characteristics were measured by weight loss (WL), bulk density (BD), dry linear shrinkage (DLS), fired linear shrinkage (FLS), water absorption (WA), and flexural strength (FS). The clays were low in <2 µm fractions (≤19%) and of medium to high plasticity with a clayey silt texture. Smectite was the dominant clay mineral while quartz and feldspar were major non clay minerals. The most abundant oxides were SiO2 (63.57–68.73%), Al2O3 (13.9–15.61%), and Fe2O3 (4.86–6.18%), whereas K2O, CaO, MgO, Na2O, TiO2, and P2O5 were depleted. Characterization based on the clay workability chart, Winkler’s diagram, and compositional ternary diagrams revealed acceptable extrusion properties and suitability for structural ceramics and earthenware. The clays showed acceptable WL, BD, LS, and WA, but unsatisfactory FS (≤1.08 MPa). Low mechanical strength was attributed to presence of smectites and inert nature of feldspar at 900 °C. Beneficiation through mixing with carbonate-rich raw materials is recommended.

Mineralogy and physic-chemical characteristics of indurated shale quarry waste and influence of firing temperature on their ceramic properties for incorporation in production of roofing tile

“…Clayey materials, which comprised mainly of clay minerals, quartz, feldspar and hematite are main the raw materials required for several branch of industries such as the fabrication of diversi ed ceramics products (Diko-Makia and Ligege 2020;Kagonbe et al 2021). Exploitation of clay materials for various industrial end-products such as structural ceramics (bricks, oor and roo ng tile) and earthenware (porcelain, household ceramics), are based basically on the raw materials availability, accessibility and comparatively low to intermediate ring temperatures (Serra et al 2013;Diko-Makia and Ligege 2020).…”

“…Clayey materials, which comprised mainly of clay minerals, quartz, feldspar and hematite are main the raw materials required for several branch of industries such as the fabrication of diversi ed ceramics products (Diko-Makia and Ligege 2020;Kagonbe et al 2021). Exploitation of clay materials for various industrial end-products such as structural ceramics (bricks, oor and roo ng tile) and earthenware (porcelain, household ceramics), are based basically on the raw materials availability, accessibility and comparatively low to intermediate ring temperatures (Serra et al 2013;Diko-Makia and Ligege 2020). The relevance of clays in economic (Kühnel, 1990;Ekosse 1994;Murray 2000) and technological development (Baccour et al 2009;Pavlova et al 2019;Kagonbe et al 2021), are due to their plasticity, inertness and stability, providing speci c properties including unique rheology, for speci c industrial use.…”

“…In Brazil, for instance, structural ceramics industries, currently consume approximately 1.5 million m 3 /year of clay as raw material (Teixera et al 2004). Ceramic roo ng tiles are typical building materials, made from raw materials such as clays, silica, uxes (feldspars) as well as coloring materials, and are used for centuries both in residential and commercial property applications (Diko-Makia and Ligege 2020;Terrones-Saeta et al 2020;Revuelta 2021). Ceramic roo ng tiles have signi cant advantages over other types of roo ng tiles not only in terms of architectural expression and durability but also in physical and mechanical characteristics.…”

“…Çolak and Özkan (2011) and Özkan (2014) carried out studies on the sintering properties of the Bornova shale (Turkey) and recommended them for possible use in the production of red red ceramics when bene ciated. Diko and Ligege (2020) evaluated tertiary volcanic cones in Limbe as raw materials in ceramic industry and recommended the materials suitable for possible use in the industry. All these form of incorporations presented favorable conditions for the implementation of waste recovery system which assisted greatly in minimizing the adverse negative effects of wastes on the environment.…”

Simple approach to elaborate test bricks for traditional ceramic studies

“…As a result, researchers are forced to rely on their own way of making bricks or to delay their study. Moreover, several research works were carried out in developing countries on building materials based on clays [1]- [3] and an alternative affordable way is a necessity for them.…”