Utilizing rejected contaminants from the paper recycling process in fired clay brick production

Abstract

Building materials drive the global economy, yet face severe environmental hurdles: resource depletion, greenhouse gas emissions, and waste generation. In order to mitigate the impact from these challenges, authorities seek sustainable and eco-friendly alternatives as an urgent need. This study focuses on the utilization of as-received rejected contaminated fines (RCF) obtained from the yellow bins' waste (paper) recycling process, in brick production. Diverse tests assessed the brick performance, including compressive strength, absorption rate, thermal conductivity, 3D CT scanning for morphological analysis, and durability analysis. Additionally, a leachate analysis was performed to evaluate the environmental implications. Economic benefits, particularly the reduction of CO2 emissions, were also evaluated. The findings confirmed that as-received waste can be utilized for fired clay brick production without the need for pulverization. The novel brick product made with as-received RCF waste exhibited superior thermal characteristics (up to a 31.25 % reduction compared to control bricks) while meeting the essential compliance requirements outlined by national standards. Moreover, each firing cycle led to a potential value of up to USD 158,460 through a reduction of 417 tonnes of CO2, resulting from a 9.5 % reduction in firing temperature (1000 °C). The results from this study offer valuable insights into the potential of using RCF waste as a sustainable alternative in the brick manufacturing industry. This alternative could address the soaring demand in the current market, resolve the escalating solid waste crisis, and mitigate clay shortages, while providing a sustainable solution for the brick industry.