International Journal of Research in Mechanical and Materials Engineering

GROUNDNUT SHELL ASH AS ALTERNATIVE RAW MATERIAL FOR WHITEWARE BODY FORMULATIONS

Matthew G.O. and Fatile B.O.*

babfat2010@yahoo.com

Whitewares, Groundnut shell ash, Ceramic raw material, Microstructure.

Groundnut shell ash (GSA) is a product of controlled burning of groundnut shells. The ash contains high percentage of silica with smaller amount of aluminium, iron, alkali and alkaline earth oxides. In this study an attempt has been made to use this waste ash as partial replacement for quartz in whiteware body formulations. Chemical analyses were carried out on the groundnut shell ash and other raw materials utilized for the body formulations. Six different samples were formulated by progressively replacing quartz with groundnut shell ash in steps of 5wt. % (from 0wt. % to 25wt. %). The samples were shaped, dried and fired between 11500C-13000C at the interval of 500C. Percentage linear shrinkage, flexural strength and water absorption tests were used to characterized the samples. The results obtained show that the linear shrinkage and flexural strength of the samples increased progressively with increase in GSA contents. The flexural strength of the samples increased with increasing substitution of quartz by GSA content up to 15% before decrease in strength is observed for most of the samples. 15wt. % groundnut shell ash containing sample fired at 12500C exhibited the maximum flexural strength value of 94.7MPa, which represents an increase in strength of 22.0% in comparison with the standard whiteware composition without GSA fired at the same temperature. The results of water absorption test show that the incorporation of GSA into the samples resulted in verification at low temperature in most of the samples. The microstructural examinations obtained from Scanning Electron Microscope (SEM) reveal that GSA containing samples have well-interlocked structure of mullite needles in the microstructure which enhanced their flexural strength.