Recycling of fly ash for development of value added products

Abstract

The present work addressed the maximum quantity of fly ash utilization in raw materials composition to fabricate fly ash based ceramic membranes and bricks. The fly ash, TiO2 and CaCO3 materials were identified as new composition for the preparation of membrane with fly ash as the major quantity. The slip casting method was employed for the preparation of both the membrane and bricks. The properties (porosity, chemical and mechanical stability and water absorption capacity) of the membrane and bricks were estimated and found stable in acidic and basic medium. Mechanical stability of the membrane was found to be 1.98 MPa. Surface morphology of membrane was identified as defect free and porosity of 39%. The parametric optimization study was carried out by response surface methodology only for the fly ash bricks. The optimal raw material compositions used for bricks fabrication were 59.24 mass % fly ash, 20.76 mass % Cement and 5 mass % sand and at which identified optimal responses of mechanical strength and water absorption capacity were 9.745 N/mm2 and 10.9%, respectively.