Recycling Feasibility of Glass Wastes and Calamine Processing Tailings in Fired Bricks Making

In this work, the recycling feasibility of treated calamine processing mine tailing (TCPMT) with glass wastes (GW) for the production of fired bricks is investigated. TCPMT was added into mixtures at a ratio of 0, 10, 20, 30, 40 and 50 % while glass waste was added separately for each formulation at ratios of 0, 5, 10 and 15 % of the dried mass of brick mixtures. The mixes of shale for brick (ShB), which consisted as the reference material, and both wastes were prepared, pressed, dried and fired at previously optimized temperature of 1020 °C. Physical, mechanical, environmental and durability properties of fired bricks were determined. The microstructural properties of fired bricks were investigated by scanning electron microscopy (SEM) and the total porosity was assessed according to ASTM standard. The results show that the increasing substitution proportion of ShB by TCPMT leads to an increase of the porosity and water absorption and to a decrease of flexural strength and density (lighter weight bricks). At the same time, the experiments showed that the addition of glass wastes into the mixtures enhances the mechanical properties of fired bricks. However, when more than 15 % of GW is used, a white scum constituted of a sodium sulphate appears at the fired brick exposed surface. Thus, fired light bricks with suitable physical and mechanical properties could be obtained from mixtures containing up to 30 % TCPMT and 10 % of GW.