Utilization of Nkpuma-Akpatakpa clay in ceramics: characterization and microstructural studies
Nkpuma – Akpatakpa clay was analysed for its ceramics suitability. Chemical, mechanical and spectral characterization of the clay was carried out to obtain more information from this clay found in commercial quantity at Ebonyi State Nigeria. The XRD analysis showed that the principal minerals in the clay are quartz, qandilite, aragonite, Muscovite and anatase. FTIR showed the stretching vibrations for Si – O at 685.8cm –1 showing the presence of Quartz. The frequency at 1431cm-1 is due to (CO3)2- stretching mode vibration or C – O stretching of Aragonite and the band at 2467.6 is due to OH- stretching. Bands observed at 984.7 and 987.7cm –1 correspond to Al – O bending vibrations which suggest the presence of muscovite in the clay and SEM studies were also carried out and reported. Porosity of the clay was 0.88% considered too small for refractory, thermal insulation and other high porosity desired ceramics applications. Value obtained for Fe2O3 was > 1.7% which accounted for why the clay did not fire white. The values for M.O.R was >40KgF/cm2. The refractoriness was <13400C. Chemical characterization showed the presence of fluxing oxides at elevated levels which are responsible for the poor refractoriness and limits the utilization of the clay to low or mid-temperature ceramics products.
Keywords: Nkpuma-Akpatakpa clay, Ceramics, Characterization, Qandilite, FTIR, Bulk density