Recycling Cigarette Butts in Ceramic Tiles

Abstract

Cigarettes are one of the favoured commodities on our planet. However, the annual consumption of 5.7 trillion cigarettes and 75% littering rate results in cigarette butts (CBs) being one of the most critical environmental issues. The leachate of heavy metals and toxic chemicals is polluting our ecosystem and threatening the wildlife species. Therefore, it is crucial to find effective and efficient recycling methods to solve the growing CB waste issue. In this study, unglazed fired ceramic tiles were manufactured with 0%, 0.5%, 1.0%, and 1.5% shredded CBs by dry mass to investigate the feasibility of the proposed sustainable recycling method. The chemical and mineralogical characterisation, density, shrinkage, bulk density, breaking strength, water absorption, and modulus of rupture were investigated and compared with the Australian Standards for ceramic tiles (AS 4459). The results revealed that tiles incorporating 0.5% CBs by mass demonstrated the greatest performance compared to the other mixtures. The water absorption for all tile–CB mixtures was found to be greater than 10%, with a positive growth tendency. The addition of 0.5% CBs by mass slightly improved flexural strength from 15.56 MPa for control samples to 16.63 MPa. Tiles containing 0.5% CBs by mass satisfied the modulus of rupture and water absorption limits for group III class according to the Australian Standards (AS 13006), and they may be suitable to be used as wall tiles. The result of a simulation equation predicts that an energy savings of up to 7.79% is achievable during the firing process for ceramic tiles incorporating 1% CBs by mass.