Polyacrylic acid to improve flotation tailings management: Understanding the chemical interactions through molecular dynamics

Gonzalo R. Quezada, Eder Piceros, PEDRO ADRIAN ROBLES VASQUEZ, Carlos Moraga, Edelmira Gálvez, Steven Nieto, Ricardo I. Jeldres

Research output: Contribution to journalArticlepeer-review

Abstract

Molecular dynamic simulations of polyacrylic acid polyelectrolyte (PAA) analyzed its interaction with the main minerals that make up characteristic tailings of the mining industry, in this case, quartz, kaolinite, and montmorillonite. The simulations were carried out with the package Gromacs 2020.3. The interaction potentials used were General AMBER Force Field (GAFF) for PAA and CLAYFF-MOH for mineral surfaces. The SPC/E model described water molecules and Lennard-Jones 12-6 parameters adjusted for SPC/E model were used for Na+ and Cl ions. The studied systems were carried out at pH 7, obtaining stable adsorption between the PAA and the studied surfaces. Interestingly, the strongest adsorptions were for montmorillonite at both low and high salt concentrations. The effect of salinity differs according to the system, finding that it impairs the absorption of the polymer on montmorillonite surfaces. However, a saline medium favors the interaction with quartz and kaolinite. This is explained because montmorillonite has a lower surface charge density and a greater capacity to adsorb ions. This facilitated the adsorption of PAA. It was possible to identify that the main interaction by which the polymer is adsorbed is through the hydroxyl of the mineral surface and the COONa+ complexes. Molecular dynamics allows us to advance in the understanding of interactions that define the behavior of this promising reagent as an alternative for sustainable treatment of complex tailings in highly saline environments.

Original languageEnglish
Article number987
JournalMetals
Volume11
Issue number6
DOIs
StatePublished - Jun 2021
Externally publishedYes

Keywords

  • Adsorption
  • Clays
  • Molecular dynamic simulation
  • Polyacrylic acid
  • Saline environment

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