Resumo:
The number of mining dams worldwide has increased, reflecting the growth in demand
and technological advances, which in turn have led to faster tailings generation. The increase
in tailings volume requires storage alternatives, whether surface, underground, or underwater
disposal. The focus, however, is on surface disposal, more specifically in earth dam reservoirs.
This type of structure undergoes rigorous safety controls; nevertheless, two major accidents in
Brazil have brought it into the spotlight, leading to a loss of public trust among downstream
communities. Brazilian legislation has been revised and now requires the geotechnical and
rheological characterization of stored tailings to develop action plans that ensure the safety of
all those involved in the event of a dam failure. The selection of parameters for these analyses
is not yet well established in the literature. Although rheology is not a new field, it has gained
more attention in recent studies. In this context, two-dimensional numerical simulations were
performed using RiverFlow 2D software for a hypothetical tailings dam failure scenario that
complies with current legislation. The simulations used real values obtained from rheological
characterization tests of two iron ore tailings samples taken from a reservoir. All scenarios were
developed using identical input data in the numerical model, modifying only the rheological
parameters based on the volumetric concentration (CV). The results showed differences starting
from the models with 30% CV. Variations in velocity, depth, wave arrival times, and flood
extent demonstrated the impact of solids concentration and rheological properties on flow
behavior. Furthermore, the influence of rheological parameters from the two samples on the
results was evident, indicating that only two samples were insufficient for this study. This
finding suggests the need for more detailed criteria for the rheological characterization of
tailings in hypothetical dam failure studies. Additionally, further research is needed on this
topic, considering the many uncertainties, variables, and social and environmental impacts
involved.
