Use of boron waste as a fluxing agent in production of red mud brick

The study was directed towards determining the usability of clay and fine wastes (CW and FW) of boron from the concentrator plant in Kirka (Turkey) as a fluxing agent in production of red mud (RM) brick. Both laboratory studies on the characterization of materials and industrial-scale tests for production of bricks were carried out. CW and FW, which have similar chemical composition but include different types and amounts of oxides, were added in amounts of 5, 10 and 15 wt% to RM, which consists of high amounts of Fe₂O₃, Al₂O₃, SiO₂ and alkalies. Six different sets of samples have been produced and fired at 700, 800 and 900 °C. Dry shrinkage of green body, bending and compressive strength, firing shrinkage, water absorption, frost resistance and harmful magnesia and lime tests on heat-treated bodies have been performed. The mineralogical and mechanical tests showed that usability of boron wastes as a fluxing agent in the production of RM bricks was possible. In addition, the samples obtained by adding 15 wt% CW and FW to RM showed the best mechanical characteristic.