New insights into pyrite-hydrogen peroxide interactions during froth flotation: experimental and DFT study

Abstract

Hydrogen peroxide (H2O2) is an efficient depressant for pyrite (FeS2) flotation. However, the depressing mechanism of H2O2 is not fully understood. In this paper, the depressing capacity of H2O2 for pyrite was examined by flotation tests. Results revealed that pyrite flotation could be inhibited by H2O2 at pH 6.4. The pyrite powder in H2O2 solution enhanced the release of O2 from H2O2. However, the O2 concentration in the solution was less than that of H2O2; thus, H2O2 is the major oxidant in the solution. Moreover, density functional theory calculations were performed to study the interactions between H2O2 and hydrated pyrite (100) surface. The H2O2 molecule tended to react with the pyrite surface to generate one S=O bond and an H2O molecule. The possible binding models of O2 molecules on the pyrite (100) surface were also studied for comparison. The O2 dissociation on the pyrite surface was more favorable than the adsorption of O2 as a whole. In addition, the orbital interaction in the S=O bond raised from the reaction of H2O2/O2 with the pyrite surface was also investigated by the density states analysis. These results provide some insights into the oxidizing effect of H2O2 in pyrite flotation.

Evaluation of the Effect of Polyethylenimine on Boron Adsorption by Soil Minerals

“…Most of the published studies, however, focus on the removal of heavy metal cations from aqueous solutions using soil minerals such as montmorillonite and kaolinite [61–65] . Novikau and Lujaniene [65] provided a comprehensive comparison of the sorption capacity against various heavy metal ions for these two minerals.…”

Counterion effects on the alkali dissolution mechanism of quartz

“…Advanced ab initio calculation (Q. Cao et al, 2023) is very successful in predicting mineral structure and physical properties. The most important thing is that the whole structure and energy of minerals can be expressed by small molecular clusters, small-scale directional forces, or covalent bonds.…”

“…(Al-Saedi et al, 2019) and other experimental simulations show that both quartz surface and carboxylate are negatively charged, and carboxylate will be repelled on the quartz surface unless it is a positively charged -COOCa + group that can bridge with the quartz surface. Lipatieva et al (2022) and Cao et al (2018) concluded that KOH solution is often used for highly selective etching of quartz and quartz etching in ternary solutions composed of NH4HF2 + isopropyl alcohol + acetic acid has been investigated (Z. Zhang et al, 2017).…”

Application of Quantum Chemistry in the Study of Flotation Reagents

“…Hydrogen peroxide (H 2 O 2 ) is another efficient pyrite depressant. Cao et al [158] studied the interaction between H 2 O 2 and hydrated pyrite (100) surfaces using DFT calculations. The results showed that the H 2 O 2 molecule is prone to react with the pyrite surface to generate an H 2 O molecule and one S=O bond.…”