Response of artificially cemented iron ore tailings for dry stacking disposal over a wide range of stresses
- Vol.53(4), Aug
- USA Springer 2023
- 904-915p.
The drawbacks associated to the conventional tailings slurry disposal in dams can be managed by stacking filtered tailings in piles. In this regard, the addition of small amounts of cement into the tailings preceding the stacking may strengthen the engineering properties of the material, permitting the construction of higher and more inclined mounts of dry tailings. Accordingly, the present study assesses the behavior of compacted iron ore tailings–cement blends for dry stacking purposes. Initially, small strain stiffness and the unconfined compressive strength tests have been carried out considering 15 combinations of dry densities and cement contents. Then, conventional drained and undrained triaxial tests were carried over a wide range of confining pressures (50–1600 kPa) considering a representative dosage. Likewise, complementary triaxial tests were performed on the natural (untreated) tailings. The initial strength and stiffness results have been successfully correlated to the adjusted porosity/cement index, whereas the triaxial testing data have shown that the addition of even a small amount of cement has completely altered the tailings response from purely frictional to cohesive frictional with a negligible change in the peak friction angle. As well, a parallel between the unconfined compression results and the triaxial testing data was established.