Utilisation of Zinc Processing Tailings (ZPTs) in Fired Clay Bricks Manufacturing: Case Study

Zinc processing tailings (ZPTs) of the Kharzet Youcef processing complex, Setif, Algeria, are mainly stockpiled in tailing dumps without use, occupying significant surfaces and negatively influencing the human environment and health. Incorporating ZPTs into building materials manufacturing is an effective solution to meet the dual objectives of environmental protection and economic development. This study investigates the influence of firing temperature and integrating ZPTs as a partial replacement for clay on the physic-mechanical properties of fired clay bricks (FCBs). Microstructural, chemical, and mineralogical analyses of ZPTs and clay were carried out by SEM-EDS, XRF, and XRD, respectively. Seven mixtures were produced with various percentages of ZPTs added to clay (0%, 5%, 10%, 15%, 20%, 25%, and 30%) and were fired at two different temperatures (900 and 1000 °C) at a ramp rate of 5 °C. Physic-mechanical tests were carried out on different brick specimens, and the results obtained showed that the FCBs incorporated with 10% of ZPTs produced the highest flexural strength of 6.24 MPa, compressive resistance of 29.78 MPa, bulk density of 1.37 g/cm3, and water absorption of 15.1% at 900 °C. Therefore, the recycling of ZPTs for FCBs manufacturing is feasible and an effective alternative waste disposal solution for sustainable development while reducing negative environmental impacts.