Abstract

One of the challenging tasks in tailings management is dealing with clay-based minerals, which create constant problems, especially in pumping thickened slurries. For their treatment, a broad range of additives has been tested in situ, where sodium triphosphate has shown some successful preliminary advantages due to its ability to disperse particles. This work aims to evaluate the adsorption capacity of sodium triphosphate in kaolinite from a theoretical molecular approach that combines quantum calculations and molecular dynamics simulation. First, triphosphate was parameterized from quantum calculations (QM) to obtain the force field that describes the system using molecular dynamics (MD) simulation. Then, MD simulations described the behavior of triphosphate in saline solutions. The results indicated that triphosphate can self-aggregate and even more in the presence of NaCl salts. The adsorption of triphosphate on kaolinite surfaces was stable and formed mainly sodium-mediated bridge-type interactions between the charged groups. The adsorption was favorable when the triphosphate concentration increased, but in the presence of NaCl, it increased only up to concentrations of 0.06 M. These latter results can be attributed to the tendency to form aggregate over the interaction with kaolinite.