Clay deposits in the Benue Valley, Northern Cameroon: mineralogical, chemical and technological characterisation for uses in ceramic bricks production

The clay deposits located in Pitoa, Benue Valley (North, Cameroon) have been the subject of physical, chemical, and mineralogical characterization, and to assess their potential utilization in ceramic bricks production. After fieldwork, four samples were chosen and investigated by Atterberg limits, particle size distribution, XRD analysis, XRF analysis, and the ceramic products' properties were appreciated after firing at temperatures of 900, 1000, and 1100 °C. From the particle size distribution (PSD) tests, the studied materials showed that the particle size spread with the clay fraction varies from 14.0 to 32.5% and sand fraction from 47 to 66%. The plasticity index is higher than 6. Mineralogically, these materials showed a dominance of quartz followed by kaolinite, smectite, and K-feldspar. According to geochemical investigation of the main components of clay, the percentage of SiO₂ was above 50%, while the percentages of Al₂O₃ and Fe₂O₃ were over 16% and 6%, respectively. The percentage of other elements like CaO, K₂O, MgO, and Na₂O was in small fractions. The technological properties of the firing products reveal that the bulk density (1.74 and 2.07 g/cm³), shrinkage (0.04-4.32%), weight loss (0.38-7.05%), and compressive strength (2.23-11.92 MPa) of firing samples increased with the temperature increases (900 °C, 1000 °C and 1100 °C) while water absorption (17.99-4.96%) and porosity (17.80-2.42%) decreases. These different results obtained on clay deposits are favorable for use in ceramic brick production.