Author
Yijun Cao
Bio: Yijun Cao is an academic researcher. The author has contributed to research in topics: Freundlich equation & Adsorption. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.
Topics: Freundlich equation, Adsorption, Molybdenite, Contact angle
Papers
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TL;DR: In this paper, various methods including flotation tests, contact angle measurements, batch adsorption tests and Density Functional Theory (DFT) simulations were carried out to understand the adaption characteristics and mechanism.
Abstract: Calcium ions are common in flotation process water, and have a significant effect on the molybdenite floatability, making separation of molybdenite from other minerals more difficult. Therefore, to improve the separation selectivity, the research of how calcium ions affect the molybdenite surface properties is of great significance. In this study, various methods including flotation tests, contact angle measurements, batch adsorption tests and Density Functional Theory (DFT) simulations were carried out to understand the adsorption characteristics and mechanism. Results of the contact angle measurements showed that the inhibition effects of calcium ions on molybdenite flotation kinetics were mostly attributed to the decrease of the edge surface hydrophobicity, as the contact angle of the edge surface decreased more than the face surface after treatment with calcium ions. While fitting the results of batch adsorption tests with adsorption kinetics and isotherm models, it was found that the Lagergen pseudo-first-order equation and the Freundlich isotherm model nicely follow the experimental trend. Moreover, DFT calculation results indicated that both Ca2+ and CaOH+ preferentially adsorb on the molybdenite (100) surface, particularly the edge surface, which was consistent with the contact angle results. Ca2+ adsorbed on the Mo-top site on the S-(100) surface by forming Ca-S bonds, transferring electrons from Ca 3d orbitals to S 3p orbitals. CaOH+ adsorbed on the S-top site of Mo-(100) surface by forming a strong covalent Mo-O bond and S-Ca bond. The results provide a basis for understanding and improving the separation effect of molybdenite from other minerals in the presence of calcium ions.
2 citations
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TL;DR: In this paper, density functional theory (DFT) calculation was taken to investigate the adsorption of reagents from the atomic and electronic microscopic perspective, and the activation mechanism of calcium was discovered.
4 citations
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TL;DR: In this paper , the use of two aluminum compounds for the precipitation of Ca 2+ and SO 4 2− in the form of ettringite was evaluated, and the amorphous aluminum hydroxide was found to be more efficient than the crystalline one, giving rise to 83% calcium and 91% sulfate removal.
1 citations