HYDROMETALLURGY
·
2021
·
IF 4.156
Yubiao Li,Qihang Xiao,Zhiming Li,Andrea R. Gerson
The slow leaching rate of molybdenite (MoS 2 ), due to its inert nature, and low recovery hinders the application of traditional hydrometallurgical processing. This study investigated the effects of grinding speed and time, molar ratio of sodium chlorate (NaClO 3 , oxidant) to MoS 2 , leaching time and temperature on the leaching efficiency of molybdenum (Mo). Grinding at low speeds via mechanical activation decreased particle size. However, at speeds over 450 rpm for 1.0 h, or at lower speeds but with longer time, it triggers a solid-state reaction (mechanochemistry) producing soluble Na 2 Mo 2 O 7 . This may be due to the existence of an energy threshold for the solid-state reaction. The most suitable activating conditions were 600 rpm for 0.5 h, with a molar ratio of NaClO 3 : MoS 2 = 5, leached in 0.1 M NaOH solution for 2.0 h at 348 K, giving rise to a Mo recovery of 74.8%. The initial acid leaching stage of the ground mixture is dominated by the dissolution of Na 2 Mo 2 O 7 , giving rise to elevated Mo recovery. The later stage is controlled by the dissolution of MoS 2 , slowing down the increase in Mo extraction. As compared to alkaline conditions, acidic leaching of MoS 2 ground at low speeds (non solid-state reaction) gives greater Mo recovery, due to the greater activity of NaClO 3 to MoS 2 under acidic conditions. However, the greatest Mo recovery is achieved in alkaline solution for MoS 2 ground at high speed (solid-state reaction) due to the occurrence of mechanochemical reaction.
研究领域:
冶金化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Hongtao Liu,Xueli Wang,Wenjie Zhang,Jiawei Wen,Junlian Wang,Jianzhong Ye,Youbei Zhan,Guoyong Huang,Shengming Xu
The spent hydrodesulfurization catalyst represents a significant hazardous solid waste due to its heavy metal content, necessitating stringent treatment protocols. Current commercial treatment methodologies predominantly employ substantial quantities of hydrochloric and sulfuric acids, resulting in severe secondary pollution, including challenging wastewater treatment and excessive sulfur and carbon emissions. This study introduces an innovative acid-free process for the treatment of spent catalysts, encompassing mineral phase reconstruction, acid-free water leaching, and solvent extraction. This novel approach achieves efficient separation and recovery of molybdenum, with a molybdenum-aluminum separation coefficient of 19,258.26 and a molybdenum recovery rate of 98.95%. The purity of the molybdenum product attained through single-stage extraction is 93.83%, which increases to 99.7% with three-stage extraction. Life cycle assessment indicates that this process reduces CO 2 emissions by 42.4% and SO 2 emissions by 73.7% compared to traditional methods. From the perspectives of environmental protection, energy conservation, and carbon reduction, this advanced process holds substantial industrial applicability.
研究领域:
环境科学
·
冶金工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Cleaner Engineering and Technology
·
2024
·
IF 5.3
Guihong Han,Yanghao Feng,Mengyu You,Hu Sun,Shengpeng Su,Bingbing Liu,Yanfang Huang
Ammonia-leaching residues of roasted molybdenite concentrates are intractable wastes and are mostly stockpiled in factories. Common treatments suffer from low Mo recovery and secondary pollution. This study has developed a synergistic process involving a single-step roasting with the addition of Al 2 O 3 and MoO 3 to recover Mo and simultaneously prepare porous refractories from the residues containing 5.6% Mo. The Mo separation efficiency, ceramic properties, and thermal behaviors—including chemical reactions, melting transformations, ceramic structure evolutions, and Mo species migrations—were comprehensively investigated. It was found that the addition of Al 2 O 3 facilitated CaMoO 4 decomposition to release volatile MoO 3 , thus promoting Mo recovery. The mullite started to form at about 900 °C, grew into whiskers, and further into interconnected clusters, under the catalytic effect of liquid MoO 3 and the sintering effect of glassy melt. Liquid MoO 3 was scattered on the outer surface of whisker clusters, achieving a high separation efficiency of over 98% after roasting at 1300 °C for 150 min. Meanwhile, a ceramic with a high porosity of 64.2% and a high compressive strength of 21.2 MPa was obtained, exhibiting promise for serving as a high-temperature insulation refractory. Overall, this study presents a novel approach for both the profound recovery of Mo and the value-added utilization of gangue minerals derived from CaMoO 4 -bearing wastes.
研究领域:
冶金工程
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材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 3
·306
·
IF 3.52
Chunling Wu,Yang Luo,Kai Zhao,Xiaobing Yu,Xian Zhang,Xuqiang Guo
In this paper, direct coal liquefaction residue was prepared from Shen-dong coal, and the solubility of the residue in five organic solvents was studied. Then, an experimental device was set up to recover molybdenum (Mo) compounds from the direct coal liquefaction residue after extraction, and the influences of sublimation temperature and duration on recycling efficiency were examined. The recycled Mo-based products were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and a thermal analyzer. The results reveal that the optimum extraction conditions were obtained through ultrasonic extraction with a quinoline solvent and the highest recycling efficiency occurred for sublimation at 900 °C for 30 min. The recycled products are identified to be α-MoO3crystals. Moreover, the α-MoO3crystal is thermally stable before the temperature reaches its melting point.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION
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2020
·
IF 2.245
Menglei Zhang,Hao Song,Chenghang Zheng,Zhenglong Lin,Yi Liu,Weihong Wu,Xiang Gao
Disposal of spent catalyst in an economical and green way has become a great concern for industrial production. We developed a process including acid leaching, solvent extraction and stripping in order to recycle spent catalyst. In this study, we conducted selective recovery of molybdenum through focus on finding an optimized extraction and stripping process by comparing different extractants and stripping agents. To separate molybdenum from other metals efficiently and figure out the mechanism of extraction process, the five different extractants of methyl trioctyl ammonium chloride, tri-n-octylamine, tris (2-ethylhexyl) amine, bis (2-ethylhexyl) phosphate, and tributyl phosphate with different functional groups were examined; the extraction ability and extraction mechanism of these five extractants were systematically studied under the same system for the first time. It was found that more than 98% of the molybdenum could be extracted with an organic phase consisting of tri-n-octylamine or methyl trioctyl ammonium chloride under the optimal conditions. The result indicated that the tri-n-octylamine and methyl trioctyl ammonium chloride possess excellent molybdenum extraction ability, the extraction capacity of the rest extractants was in the order of bis (2-ethylhexyl) phosphate > tris (2-ethylhexyl) amine > tributyl phosphate. In the stripping process, NH4OH, NaOH, and H2SO4 were chosen as stripping agent to strip the molybdenum from the loaded tri-n-octylamine organic phase. The stripping ability of the three studied stripping agents was in the order NaOH > NH4OH > H2SO4. The Fourier transform infrared (FTIR) spectra showed that the structure of the tri-n-octylamine organic phase was stable during the extraction and stripping process. Results showed that molybdenum could be highly and efficiently recovered by optimized extraction and stripping process.Implications: A series of different extractants and stripping agent have been systematically studied in order to compare their extraction and stripping ability under the same system. Based on the obtained results, an optimized extraction and stripping process was proposed to recycle molybdenum from spent catalyst efficiently. It is possible to dispose spent catalysts in an economic and environmental way by this developed metal recovery process.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Yao-Jen Tu,Ting-Shan Chan,Hao-Wei Tu,Shan-Li Wang,Chen-Feng You,Chien-Kuei Chang
An efficient method for removing and recovering molybdenum (Mo) from water was developed by using ZnFe 2 O 4 nanoparticles . The Mo adsorption displayed a nonlinear isotherm that fitted well with the Langmuir isotherm , showing limited adsorption sites on the surface of ZnFe 2 O 4 . The adsorption of Mo(VI) was dependent on solution pH. With increasing pH, the build-up of negative charges of both adsorbent and adsorbate led to enhanced electric repulsion between them. The K -edge XANES spectra for the adsorbents collected after Mo adsorption revealed that Mo(VI) was the predominant oxidation state sorbed on ZnFe 2 O 4 , indicating that the reduction of Mo(VI) did not occur on ZnFe 2 O 4 . The different peak positions of k-space and R-space shown in K-edge EXAFS spectra demonstrated that the adsorbed Mo could be bound on the surface or be slipped in the vacancy position of the ZnFe 2 O 4 crystal. Importantly, Mo could be efficiently adsorbed from photoelectric industrial wastewater and these adsorbed Mo anions were rapidly replaced by OH − ions, implying the potential for Mo removing and recovering in industrial wastewater.
研究领域:
环境科学
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纳米材料
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水处理
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吸附化学
·
环境工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Hu Sun,Mengyu You,Zhuoxun Yang,Bingbing Liu,Yanfang Huang,Guihong Han
Existing methods for producing pure MoO 3 from low-grade molybdenite concentrates suffers from complex unit operations, suboptimal metal recovery, excessive reagent/energy consumption, and substantial wastewater generation. This work presents a novel metaphosphate-quartz-assisted volatilization roasting process for the direct preparation of pure MoO 3 from pelletized low-grade molybdenite concentrates. Single-factor experiments demonstrated that the addition of Al(PO 3 ) 3 and quartz significantly increased molybdenum recovery (by over 25 %) while maintaining pellet structural integrity during roasting. The optimal result—97.1 % molybdenum volatilization efficiency—was achieved under the following conditions: a mass ratio of ore: Al(PO 3 ) 3 : quartz = 1: 0.2: 0.2, and temperature-programmed oxidative roasting from 900 °C to 1050 °C for 65 min. Additionally, the crystallized MoO 3 volatile exhibited a high purity of 99.9 % and was further upgraded to 99.99 % purity through a simple water washing. The intensification of molybdenum separation was attributed to two primary mechanisms: (i) Al(PO 3 ) 3 triggered decomposition reactions of molybdates, releasing volatile MoO 3 ; (ii) quartz expansion and interconnected pyrophosphate/phosphate networks maintained a mechanically robust yet porous structure that enabled efficient MoO 3 transfer while reducing vapor contamination caused by dust. In general, the new approach can overcome the negative effects derived from impurities, and offers significant advantages, including much fewer procedures, lower reagent consumption, zero wastewater discharge, and high molybdenum recovery.
研究领域:
冶金学
·
矿物加工
·
提取冶金
·
可持续工程
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）