Preparation and Characterization of Porcelain Electrical Insulator using Sugarcane Bagasse Ash (SCBA)

Abstract

In this study, two clay materials mined from Bombawuha (BC) and Denkaka (DC), two feldspar materials collected from Arerti (AF) and wolkite (WF) and quartz mined from Chancho (CS), as well as SCBA waste collected from Wonji Shewa sugar factory of Ethiopia was characterized to evaluate their potentials as raw materials for producing quality electrical porcelain insulators. A total of 5kg samples of the aforementioned raw materials were collected, dried, and ground to sieve size of 63µm for clays, feldspars, and sugarcane bagasse ash and 45µm for sand, then the mineralogy, chemical composition, thermal property, plasticity, and particle size distribution of raw materials were characterized by using x-ray diffractometry (XRD), atomic absorption spectrometer (AAS), Thermogravimetry analysis (DTA-TG), Atterberg plasticity test, sieve- hydrometer analysis, respectively. Four different body compositions were formulated by varying the relative proportion based on the raw material potential characteristic. A total of one hundred thirty-two (132) (one hundred eight (108) a cylindrical shaped for physical and electrical strength test and twenty-four (24) a rectangular-shaped for mechanical strength test) bodies of the desired formulations were prepared and labeled as with composition SCBA0 ( 50% clay, 40% mixed Feldspar, 10% sand and 0% SCBA ), SCBA10 ( 50% clay, 30% mixed Feldspar, 10% sand and 10% SCBA ), SCBA15 ( 50% clay, 25% mixed feldspar, 10% sand and 15% SCBA ) and SCBA20 ( 50% clay, 20% mixed feldspar, 10% sand and 20% SCBA ), the batches were fired at firing temperature of 1200°C, 1250°C, and 1300°C and firing time of 1.5hr, 2hr and 2.5hr. Finally, the fired products were investigated for their physical properties (water absorbance, bulk density, and apparent porosity), electrical properties (dielectric strength), mechanical strength (modulus of rupture), and phase analysis by XRD. The physical-mechanical properties and dielectric strength measured for each porcelain sample confirmed batch SCBA10 with the composition of (10% SCBA waste, 50% BC, 30% mixed Feldspar (AF and WF in 50:50%), and 10% CS) fired at 1250°C and at firing time 2.5hr was found to have the dielectric strength of 6.59 kV/mm, bending strength of 42.53 MPa and water absorption of 0.35%, which satisfies the obligatory properties for porcelain insulators. In conclusion, this study confirmed that quality porcelain electrical insulators could be produced using locally available raw materials (Clay, Feldspar, and quartz) and the partial replacement of Feldspar by sugarcane bagasse ash waste.