Pre-industrial scale prototypes of ceramic wall tiles with bio-calcium carbonate from eggshell waste
VILARINHO I. 1, CAPELA M. 1, SILVA J. 2, BATISTA S. 2, VÁSQUEZ F. 3, SEABRA M. 1
1 CICECO – Aveiro Institute of Materials/DEMaC - Department of Materials and Ceramic Engineering, University of Aveiro, Aveiro, Portugal; 2 Mota Ceramic Solutions, Oiã, Portugal; 3 Instituto de Tecnología Cerámica (ITC), Asociación de Investigación de las Industrias Cerámicas (AICE), Campus Universitario Riu Sec, Castellón, Spain
The unsustainable use of natural resources is causing several environmental problems. Therefore, interest in waste valorization is increasing due to environmental and economic benefits. In 2018, approximately 8.5 million tons of eggshell waste were generated worldwide and, usually, landfilling is the only option. Therefore, the development of added-value applications for eggshell waste is of utmost importance. The present work aims to study, at a pre-industrial scale, the production of ceramic wall tiles with bio-CaCO3 from eggshell waste. Firstly, the eggshell residue was pre-treated in a new and innovative industrial prototype that separates the membrane from the shell through a simple and low-cost process. Then, atomized powders were produced substituting the limestone with different levels (0, 50, 75 and 100 wt.%.) of the eggshell residue. Pre-industrial ceramic tiles (10 x 10 cm2) were produced for each formulation and tested. The ceramic wall tiles were glazed with opaque and white glazes and fired at an industrial furnace and their properties were evaluated. Through specimens’ characterization, no significant differences were observed, and all values are within industrial limits. Therefore, this work proved that, for ceramic wall tiles, the limestone can be totally substituted by bio calcium carbonate from eggshell waste. The developed products will contribute to reducing the amount of waste deposited in landfills and the consumption of virgin raw materials.