Suitability of Thulamela Clays for Use in The Ceramic Industry: A Case Study in Thulamela Municipality, Limpopo Province, South Africa

Abstract

This study investigated the suitability of Thulamela Municipality clay samples for ceramic applications by examining their physical, chemical, and mineralogical properties. A comprehensive analysis was conducted using various tests, including particle size analysis, Atterberg limits, X-ray fluorescence (XRF), and X-ray diffraction (XRD). The study evaluated the clays' strength, cracking, water absorption, and linear shrinkage during and after firing at different temperatures (300°C, 700°C, 800°C, 900°C, and 1150°C), aiming to assess their potential for ceramic use. The study analysed the physical and chemical properties of clays from various locations. Sieve analysis revealed well-distributed particle sizes, while hydrometer analysis showed varying clay and sand content. Atterberg limit tests indicated high plasticity, and XRF analysis identified aluminium oxide (Al2O3), silicon dioxide (SiO2), and iron oxide (Fe2O3) as dominant chemical elements. XRD analysis detected quartz, kaolinite, and hematite as primary minerals, with variations between samples. The study identified Ha-Matsika, Lwamondo, Muledane, and Dzingahe clays as having optimal ceramic properties, suitable for high-end applications like refractory ceramics and sanitary ware. These clays exhibited moderate to low water absorption rates and stable linear shrinkage behaviour. In contrast, clays from Ngwenani, Madadani, Tshilungoma, and Tshino are better suited for less demanding ceramic products. The study's findings have significant implications for the ceramic industry, highlighting the potential of local clay resources for producing high-quality ceramics. The study recommends further research to improve the properties of certain clays (Ngwenani, Madadani, Tshilungoma, and Tshino). Utilising local clay resources can enable the ceramic industry to adopt sustainable practices, produce high-quality products, and promote environmentally friendly manufacturing.