The erosion resistance of iron ore tailings measured by jet erosion tests

The management of Iron Ore Tailings (IOT) is an important aspect of efficient and environmentally sound iron ore mining activities. Like natural soils, IOT are subjected to soil erosion processes as a consequence of water flow, which may eventuate to catastrophic failures of tailings storage facilities (e.g. in overtopping of tailings dams) or contribute to spread of hazardous materials (e.g. in sheet/rill erosion of tailings dumps). This study investigates the erosion resistance of IOT from two major iron ore mines, namely ‘Golgohar’ and ‘Chadormalu’, located in Iran. Jet erosion tests (JETs) were performed on the IOT and the tailings treated with 2% cement. The erodibility/detachment coefficient (kd) and critical shear stress (τc) were determined. Test results indicated that the compacted iron ore tailings were ‘very erodible’ to ‘erodible’ displaying τc values as low as 0.002 N/m2 and kd as high as 14.18 cm3/Ns. Moreover, treatment of tailings with 2% cement improved erosion resistance by lowering kd and increasing τc, to the extent that cement-treated IOT were deemed ‘moderately resistant’ to erosion. Regarding practical applications, erosion parameters from JETs were implemented in evaluation of processes; namely, headcut migration and breach widening, evolving in overtopping erosion and breach formation of tailings embankments.