New insights into the reagent-removal mechanism of sodium sulfide in chalcopyrite and galena bulk flotation: a combined experimental and computational study

Lu, Hongbo; Xu, Zhijie; Wang, Changtao; Sun, Wei; Wu, Meirong; Dong, Yong; Bai, Limei

doi:10.1016/j.jmrt.2020.03.062

Cited by 30 publications

(4 citation statements)

References 41 publications

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“…The sulfur oxidation sites involved in eq was in the pyrogenic carbon pores, which widely existed in activated carbon and did not inhibit affect the adsorption of oxygen and the formation of • OH (Figure S17, Figure S14). The lower E ° (S, H + / HS – ) = 0.19 V relative to E ° in eqs and suggested that the generation of • OH was thermodynamically favorable on Na 2 S/C (pyrogenic carbon coupled with sulfide). , In this system, Na 2 S/C acted as a Fenton-like reagent to activate H 2 O 2 (eq ).…”

Section: Resultsmentioning

confidence: 88%

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Pyrogenic Carbon Initiated the Generation of Hydroxyl Radicals from the Oxidation of Sulfide

Wang

Huang

et al. 2021

Environ. Sci. Technol.

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Sulfide is one of the most abundant reductants in the subsurface environment, while pyrogenic carbon is a redox medium that widely exists in sulfide environment. Previous studies have found pyrogenic carbon can mediate the reductive degradation of organic pollutants under anoxic sulfide conditions; however, the scenario under oxic sulfide conditions has rarely been reported. In this study, we found that pyrogenic carbon can mediate hydroxyl radicals ( • OH) generation from sulfide oxidation under dark oxic conditions. The accumulated • OH ranged from 2.07 to 101.90 μM in the presence of 5 mM Na 2 S and 100 mg L −1 pyrogenic carbon at pH 7.0 within 240 min. The Raman spectra and electrochemical cell experiments revealed that the carbon defects were the possible chemisorption sites for oxygen, while the graphite crystallites were responsible for the electron transfer from sulfide to O 2 to generate H 2 O 2 and • OH. Quenching experiments and degradation product identification showed that As(III) and sulfanilamide can be oxidized by the generated • OH. This research provides a new insight into the important role of pyrogenic carbon in redox reactions and dark • OH production.

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Section: Resultsmentioning

confidence: 88%

“…The lower E°(S, H + / HS − ) = 0.19 V relative to E°in eqs 4 and 5 suggested that the generation of • OH was thermodynamically favorable on Na 2 S/ C (pyrogenic carbon coupled with sulfide). 71,72 In this system, Na 2 S/C acted as a Fenton-like reagent to activate H 2 O 2 (eq 8).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Pyrogenic Carbon Initiated the Generation of Hydroxyl Radicals from the Oxidation of Sulfide

Wang

Huang

et al. 2021

Environ. Sci. Technol.

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“…Surface sulfidization, however, is not always favorable for collector adsorption. For instance, a DFT study showed that chalcopyrite and galena surface sulfidization by Na 2 S prevents the adsorption of xanthate collectors on the mineral surfaces and thus reduces flotation recovery . The higher interaction of sodium sulfide with the chalcopyrite and galena surfaces was introduced as an indication of a significant reagent-removal effect of Na 2 S in the chalcopyrite-xanthate and galena-xanthate systems.…”

Section: Applications Of Molecular Modeling To Froth Flotationmentioning

confidence: 99%

Emerging Trends of Computational Chemistry and Molecular Modeling in Froth Flotation: A Review

et al. 2023

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Froth flotation is the most versatile process in mineral beneficiation, extensively used to concentrate a wide range of minerals. This process comprises mixtures of more or less liberated minerals, water, air, and various chemical reagents, involving a series of intermingled multiphase physical and chemical phenomena in the aqueous environment. Today’s main challenge facing the froth flotation process is to gain atomic-level insights into the properties of its inherent phenomena governing the process performance. While it is often challenging to determine these phenomena via trial-and-error experimentations, molecular modeling approaches not only elicit a deeper understanding of froth flotation but can also assist experimental studies in saving time and budget. Thanks to the rapid development of computer science and advances in high-performance computing (HPC) infrastructures, theoretical/computational chemistry has now matured enough to successfully and gainfully apply to tackle the challenges of complex systems. In mineral processing, however, advanced applications of computational chemistry are increasingly gaining ground and demonstrating merit in addressing these challenges. Accordingly, this contribution aims to encourage mineral scientists, especially those interested in rational reagent design, to become familiarized with the necessary concepts of molecular modeling and to apply similar strategies when studying and tailoring properties at the molecular level. This review also strives to deliver the state-of-the-art integration and application of molecular modeling in froth flotation studies to assist either active researchers in this field to disclose new directions for future research or newcomers to the field to initiate innovative works.

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“…Galena and sphalerite are the main sources of Pb and Zn extracted by these industries and often coexists in nature [3,4]. Galena is naturally hydrophobic, making it suitable for flotation separation [5][6][7][8][9][10]. The floatability of sphalerite, on the other hand, depends on its impurities, particularly the iron content.…”

Section: Introductionmentioning

confidence: 99%

Effects of seawater on the adsorption of xanthate onto galena and sphalerite

Song,

Yao,

Yin

2024

J. Phys.: Conf. Ser.

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Seawater contains divalent calcium and magnesium cations. Under alkaline conditions, calcium and magnesium ions react with hydroxide ions to form insoluble hydroxyl complexes or hydroxide precipitates. The hydrophilic substances that may be adsorbed on the mineral surface during the flotation process hinder the adsorption of the collector, affecting mineral hydrophobicity, and thus reducing the floatability of the mineral. In this study, the effects of seawater on the adsorption of xanthate onto galena and sphalerite were investigated. The results show that under strong alkaline conditions, seawater has significant and slight adverse effects on sphalerite and galena, respectively. Flotation regulators such as ethylenediamine tetraacetic acid, sodium hexametaphosphate, and sodium silicate can eliminate the adverse effect on galena and sphalerite flotation to a certain extent. The mechanisms were revealed through microflotation experiments, contact angle measurements, bubble-particle attachment tests, zeta potential measurements, and XPS analysis.

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New insights into the reagent-removal mechanism of sodium sulfide in chalcopyrite and galena bulk flotation: a combined experimental and computational study

Cited by 30 publications

References 41 publications

Pyrogenic Carbon Initiated the Generation of Hydroxyl Radicals from the Oxidation of Sulfide

Pyrogenic Carbon Initiated the Generation of Hydroxyl Radicals from the Oxidation of Sulfide

Emerging Trends of Computational Chemistry and Molecular Modeling in Froth Flotation: A Review

Effects of seawater on the adsorption of xanthate onto galena and sphalerite

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