Abstract
This study evaluated the potential of locally sourced-ceramic raw materials in Tanzania, Pugu kaolin, Same clay, vermiculite and feldspar, for production of high voltage porcelain insulators. The chemical, mineral phases and microstructural characterization of raw materials and porcelain samples were carried out using the X-ray fluorescence, X-ray diffraction, and scanning electron microscopy techniques, respectively. The mineral phases of the fired porcelain sample identified were mullite and quartz. The porcelain bodies were fabricated using the dry pressing method by varying the composition of the selected ceramic raw materials. The physical-mechanical properties and dielectric strength were measured for each porcelain sample. The sample with the composition of 20% Pugu kaolin, 20% Same clay, 20% vermiculite and 40% feldspar was found to have the dielectric strength of 50.8 kV.mm-1, bending strength of 20 MPa and water absorption of 0.46%, which satisfies the main requisite properties for high voltage porcelain insulators.
Keywords:
vermiculite; porcelain insulator; physical-mechanical properties; dielectric strength
