Valorization of Iron Ore Tailings from Nador, Morocco, as a Sustainable Additive in the Manufacture of Red Clay Fired Bricks

Abstract

High iron ore production generates substantial solid waste. Storing this waste in dams poses environmental issues and safety risks for the population. The aim of this study was to valorize sterile waste (IOT) from an inactive iron mine in the Nador region of northeastern Morocco, as an additive in the manufacture of fired bricks made from a red clay (AJH) extracted from the Oujda region. For this purpose, brick specimens were obtained using a mix of a 40% of AJH and 60% of IOT. Physico-chemical, geotechnical and mineralogical characterization techniques were applied to qualify raw material. IOT consisted of hematite, magnetite, pyrite, jarosite and quartz and AJH of kaolinite, chlorite, calcite, hematite, dolomite, quartz and vermiculite. After firing the specimens at 500 °C, 850 °C and 1100 °C, mineralogical composition, bulk density, compressive strength and microstructure behavior of the specimens was assessed. The compressive strength of the bricks containing IOT is 1.25 MPa at T = 500 °C and it varies little at 1100 °C. The compressive strength of the reference sample is 2.94 MPa at 1100 °C. The material has low vitrification and greater porosity compared to the reference bricks. Adding IOT brings significant changes to the color of fired bricks.