mineralogical and physicochemical characterization of ngaye alluvial clays (northern cameroon) and assessment of its suitability in ceramic production

This study reports the physicochemical analysis of three alluvial clastic clays from the Ngaye River in northern Cameroon. X-ray diffraction, infra-red spectroscopy, scanning electron microscopy and thermal analysis are used to establish the mineralogical composition. It is found that the main clay minerals in these samples are kaolinite, muscovite-illite and smectite associated with quartz, goethite, feldspars and anatase. This mineralogical assemblage is in accordance with the chemical analysis which further confirmed the high quartz proportion. The low content in fluxing agent is indicated by the low contents in Na2O, K2O, MgO and CaO. The low content in fluxing agent and high sand proportion result in poor vitrification in ceramic testing brick obtained at 900 °C, 1000 °C and 1100 °C. For all the firing temperatures, linear shrinkage varied from 0.7% to 2.6%, weight loss varied from 3.5% to 7%, bulk density varied from 1.6 to 1.8 g/m3, water absorption decreased from 20.7% to 12.7%, and flexural strength (σ) varied from 0.60 to 2.07 MPa. The Ngaye alluvial clastic clays could be used in the fabrication of bricks (commons and perforated). However, an increase of fluxing agent and clays is needed to improve the mechanical performance of the ceramic products.