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Your search keyword '"Guohua Ye"' showing total 3 results
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3 results on '"Guohua Ye"'

1. Effect of Fluoride Ions on the Surface Dissolution of Vanadium-Bearing Biotite

Author

Yuanyuan Tao, Guohua Ye, Hao Zhang, Yujie Hu, Qi Zuo, Xiao Wang, Siqin Zhu, Xuanxiong Kang, Yun Zhang, Xinyue Xiang, Yiyang Rong, and Changxu Song

Subjects
vanadium, leaching, dissolution, DFT calculation, Physics, QC1-999, Chemistry, QD1-999
Abstract

In shale vanadium ore, vanadium is mainly formed as a low-V(III) homogeneous phase to partially replace Si and exists in the lattice structure of aluminosilicate minerals such as biotite. During the acid leaching of shale vanadium ore, an activator is needed to effectively extract vanadium. Using biotite as a tetrahedral structure doped with Aluminum-Silicon tetrahedron structure, the interaction between leaching-agent ions (H+), activator ions (F−), and vanadium-containing biotite surface was discussed by DFT quantum chemical calculations. The dissolution behavior of activator fluoride ions on the surface of vanadium-bearing biotite during sulfuric acid leaching was revealed. According to the simulated leaching results, the oxygen on the biotite surface first absorbed hydrogen ions to undergo complete hydroxylation, and then combined with hydrogen ions to form water molecules. However, in the presence of activator (NaF), fluoride ions were adsorbed on the surface cations, which catalyzed the formation of water molecules and promoted the dissolution of surface cations. SEM–EDS analysis showed that the surface of vanadium-bearing minerals became very irregular, and the number of voids and cracks greatly increased. At the same time, XPS showed that the addition of activator fluoride ions destroyed the Al-O tetrahedron structure. Many Al and V atoms dissolved in the solution, which improved the leaching rate of vanadium.

Published
2022
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2. Effect of activator on kinetics of direct acid leaching of vanadium from clay vanadium ore

Author

Pengzhi Xiang, Guohua Ye, Tang Yue, Hu Yujie, Tao Yuanyuan, and Ziyang Chen

Subjects
Order of reaction, Diffusion, Kinetics, Vanadium, chemistry.chemical_element, Filtration and Separation, Sulfuric acid, Activation energy, Analytical Chemistry, chemistry.chemical_compound, chemistry, Leaching (metallurgy), Fluoride, Nuclear chemistry
Abstract

According to the characteristics of clay vanadium ore, a novel process of no-grinding and no-roasting direct activated acid leaching under atmospheric pressure, was proposed. And in order to improve the leaching efficiency of vanadium, new activator MF was added into the acid leaching process. The effects of main factors on acid leaching of vanadium were investigated. The results showed that the leaching efficiency of vanadium reached 96.14 % under the conditions as follows: mass ratio of manganese oxide to fluoride is 25 %: 75 %, activator dosage of 3 %, H2SO4 dosage of 25 %, leaching temperature of 90 ℃, and leaching time of 5 h. The leaching kinetics was studied by using the unreacted shrinking core model. It was found that under the optimum conditions, the control step of direct activated acid leaching of vanadium from clay vanadium ore is changed from hybrid control to diffusion control, the apparent activation energy is reduced from 36.30 kJ‧mol−1 to 12.54 kJ∙mol−1, and the reaction order of sulfuric acid is reduced from 2.9033 to 1.8114.

Published
2022
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3. A DFT-based method to determine the hydrophobicity change mechanism on sphalerite and pyrite surfaces caused by sodium dithionite

Author

Jibo Qiao, Qi Zuo, and Guohua Ye

Subjects
Chemistry, Orbital hybridisation, Inorganic chemistry, chemistry.chemical_element, Zinc, engineering.material, Sulfur, Sodium dithionite, chemistry.chemical_compound, Colloid and Surface Chemistry, Adsorption, Sphalerite, engineering, Density functional theory, Pyrite
Abstract

In this study, density functional theory (DFT) was used to investigate the separation mechanism of sphalerite and pyrite in the presence of sodium dithionite. The results showed that S atoms were preferred over Zn atoms on the ZnS (1 1 0) surface, but, the S atom was less reactive than the Fe atom on the FeS2 (1 0 0) surface. The S atom played a key role in interactions with atoms on the mineral surface. No orbital hybridization occurred between the S 3p and O 2p orbitals of S2O42–, and the Zn 3d orbitals on the ZnS (1 1 0) surface. Strong chemical interactions occurred between S, O, and Fe, via the hybridization of the S 3s, 3p, and O 2p orbitals of S2O42– and the Fe 3p, 3d, and 4s orbitals on the FeS2 (1 0 0) surface. In the presence of S2O42– prevented the collector from being effectively adsorbed by active particles on the surface of pyrite, which changed the hydrophobicity of pyrite. In the flotation experiments, the S2O42– ion was used as an inhibitor for pyrite to separate zinc and sulfur.

Published
2021
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