Sugarcane Bagasse ash substituent feldspar for the production of porcelain electrical insulators

Abstract

Sugarcane bagasse ash (SCBA) industrial waste was used to partially substitute feldspar in the production of porcelain electrical insulators from a mixture of locally available Bombawuha clay (BC), Chancho sand (CS), and mixture of Wolkite (WF) and Arerti feldspar (AF) (50:50%). The raw materials were characterized for their chemical composition, mineralogy, thermal behavior, and plasticity. The porcelain electrical insulator formulations containing various proportions of SCBA (0 wt%, 10 wt%, 15 wt%, and 20 wt%) were fired at different firing temperatures of 1200 °C, 1250 °C, and 1300 °C for 2.5 h. The fired bodies were evaluated for water absorption, apparent porosity, bulk density, flexural strength, dielectric strength, and microstructure. The results showed that SCBA had 65.06% silica (SiO2) and had higher alkaline and iron oxide (Fe2O3) contents than the natural feldspars. Bombawuha clay contained kaolinite as a major mineral with a middle range plasticity index (PI = 11.2%) and the met the required purity necessary for mullite phase formation. The feldspars had a low alkali content of sodium oxide plus potassium oxide (Na2O + K2O) of < 6 wt %. The prepared porcelain insulator containing 10% SCBA, 50% BC, 30% mixed feldspars, and 10% CS, and fired at 1250 °C for 2.5 h exhibited a water absorption of 0.35%, flexural strength of 42.50 MPa, and a dielectric strength of 6.59 kV/mm, which satisfies the obligatory properties for quality porcelain insulators. Further, the partial replacement of feldspar by SCBA up to 10 w% lowered the firing temperature by 50 °C.