Nzeugang N.A.,Local Material Promotion Authority MIPROMALO |
Nzeugang N.A.,Laboratory of Alterology and Engineering Geology |
Eko M.R.,Laboratory of Alterology and Engineering Geology |
Fagel N.,Laboratory of Clays |
And 5 more authors.
Clay Minerals | Year: 2013
Clayey deposits of Nanga-Eboko (central Cameroon) were studied to assess their potential as building materials. Characterization was performed using XRD, FTIR, XRF, DTA/DTG and firing testing. Clays appear as discontinuous pockets with the same textural characteristics in three villages located on both sides of the Sanaga River. The average thickness of the exploitable layer is about 3m. The estimated tonnage ∼7-17 × 105 m3 can supply a brick industry of great importance. SiO2 (∼70%), Al 2O3 (∼15%) and Fe2O3 (∼4%) are the predominant oxides of the natural clays. Quartz (∼55%), kaolinite (∼33%), illite (∼5%) and K-feldspar (∼4%) are major minerals. Clays are not suitable for building construction due to their fine-grained size and high plasticity properties. Firing properties of bricks (950 and 1050°C) are good despite the high shrinkage values. Therefore the addition of '' degreasers '' is recommended to control shaping and drying. © 2013 Mineralogical Society.
Nzeukou N.A.,Local Material Promotion Authority MIPROMALO |
Nzeukou N.A.,University of Yaounde I |
Traina K.,Innovative Solutions |
Medjo E.R.,University of Yaounde I |
And 6 more authors.
InterCeram: International Ceramic Review | Year: 2014
The sintering behavior and mechanical properties of four alluvial clays sampled from the Sanaga River (sampling sites: Nanga-Eboko, Mbandjock, Batschenga, and Ebebda), central region of Cameroon were investigated. Specimens were shaped by cold pressing and fired between 850 and 1100 °C. X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy were used to monitor microstructural modifications and thermal phase transformations. Linear shrinkage, density, open/closed porosity, and water absorption were used to assess the effects of firing cycle on the mechanical properties of the fired compacts. The results showed that between 850 and 1050 °C the mineralogical phases are mainly quartz and feldspar. Mullite, spinel, and cristoballite appear at 1100 °C together with viscous phases. The values of apparent density (2.62-2.76 g/cm3), open porosity, and flexural strength (3-30 MPa) of the brown compacts suggest the possible use of these clays for earthenware ceramics such as building bricks, roof and floor tiles.
Nzeugang Nzeukou A.,Laboratory of Clays |
Nzeugang Nzeukou A.,Laboratory of Alterology and Engineering Geology |
Fagel N.,Laboratory of Clays |
Njoya A.,University of Dschang |
And 4 more authors.
Applied Clay Science | Year: 2013
Alluvial clays from four localities along the Sanaga River (Center Cameroon) were studied by physico-chemical, mineralogical and technological characterization in order to assess their suitability as ceramic raw materials. The chemical compositions indicated that SiO2 (65-70%) and Al2O3 (12-15%) are major elements while Fe2O3 is less (4-7%). Kaolinite, quartz and feldspar are the main minerals. Particle size distribution and chemical composition are indicative of "plastic red clays" belonging to heavy sandy clays group. Their medium to high plasticity is suitable for fired earth and fine ceramics products. Pressed samples were fired at temperatures ranging between 900 and 1100°C for coarse ceramic products. Linear shrinkage, flexural strength and water absorption indicated that the clays from one site (Mbandjock) are good for brick making. Clays from the three other localities present poor technological properties (higher shrinkage and cracks), they need degreasers before use as ceramic raw materials. Although water absorption and flexural strength parameters are good for all the studied samples, firing shrinkage needs to be improved. © 2013 Elsevier B.V.