The Ndop plain clayey materials (Bamenda area – NW Cameroon): Mineralogical, geochemical, physical characteristics and properties of their fired products

Abstract

The physicochemical, mineralogical and technological properties of clayey materials from the Ndop plain (NW Cameroon) have been investigated, for their ceramic applications. The clayey materials have mixed facies with colour ranging from brown, grey, mottled and yellowish brown. The thickness of the exploitable clay layer is more than 5 m. Their mineralogical constituents are quartz, kaolinite, illite and feldspars, with kaolinite as major clay mineral. Based on the geochemistry, their source rocks might be felsic, with a mafic rock inference. These materials display high percentage in fine particles and high Atterberg limits. For all the firing temperatures, flexural strength (1.2–11 MPa), water absorption (8.03–24.27%), linear shrinkage (2.10%), weight loss (4.88–16.54%) and bulk density (1.57–2.03 g/cm3) indicate good ceramic properties for firing samples between 900 and 1100 °C. Most of the fired test bricks show a brick red colour with good to very good cohesion. The studied clays were thus, suitable as raw materials for roof tiles, light weight blocks and hollow bricks; however, mixing of high clayey and highly silty materials could improve the quality of the products.

Keywords

• Clays
• Physicochemistry
• Kaolinite
• Ceramic