METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
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2024
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IF 2.4
Zhang Yuanbo,Lin Kun,Su Zijian,Chen Xijun,Ma Ke,Jiang Tao
The proportion of pellets in the blast furnace charge structure is gradually increasing, among which magnesium-bearing fluxed pellets have been widely applied due to their excellent metallurgical properties. To further determine the consolidation mechanism in different reaction layers of magnesium-bearing fluxed pellets, the phase transformation and diffusion behaviors of Fe 3 O 4 –MgO in different roasting atmospheres were investigated in this study. The results showed that Fe 2+ preferentially diffused to the MgO layer and combined with Mg 2+ to form Mg y Fe 1− y O in inert atmosphere, and then, Fe 3+ and Fe 2+ binded to Mg 2+ to form [(MgO) x (FeO) 1− x ]·Fe 2 O 3 (0 ≤ x ≤ 1). The increase of roasting temperature was favorable for the entry of Mg 2+ into the spinel phase. In air atmosphere, Fe 3 O 4 was first oxidized to Fe 2 O 3 . Fe 3+ and Mg 2+ counter-diffused and then combined to Mg x Fe 3− x O 4 ( x = 1). Fe 3 O 4 reacted more readily with MgO in inert atmosphere than in air atmosphere. It was favorable to increase the oxygen partial pressure for Mg x Fe 3− x O 4 ( x = 1) generation. The diffusion rate of Mg 2+ at the interface of Fe 3 O 4 –MgO system in inert atmosphere was 1.88 µ m/min at 1200 °C, which was faster than that of 1.49 µ m/min in air atmosphere. Graphical Abstract
研究领域:
冶金学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2019
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IF 4.029
Chen-Hua Lou,An-Nan Chen,Lu Lu,Jia-Min Wu,Li-Jin Cheng,Rong-Zhen Liu,Shuang Chen,Ying Chen,Yu-Sheng Shi,Chen-Hui Li
MgO-doped Ba 0.67 Sr 0.33 TiO 3 (BST) ceramics with uniform microstructure and enhanced dielectric loss were prepared by direct coagulation casting via high valence counter ions (DCC-HVCI) method. MgO was utilized as acceptor dopant as well as coagulating agent to release Mg 2+ solidifying ceramic suspensions. Effect of sintering temperature and MgO doping content on microstructure and dielectric properties of BST ceramics was investigated. It was found that the loss tangent value (tan δ) decreased remarkably from 0.025 to 0.004 with increasing MgO concentration from 0.5 to 1.5 mol%. The 1.5 mol% MgO-doped BST ceramics processed high density of 99.5% and tan δ of 0.004 which is improved by 150% compared with that of dry-pressed samples. This improvement can be attributed to the ubiquitous distribution of MgO in BST ceramic matrix leading to the enhanced inhibitive effect. This paper provides a novel facial route to prepare high-performance functional ceramics with high reliability and low cost.
研究领域:
材料科学
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电子材料
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DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2025
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IF 3
Hongyu Ding,Yujie Yang,Hao Li,Zhenyu Zhang,Zhihao Geng
In this paper, (FeCoNi) 86 Al 7 Ti 7 high entropy alloys powder is mixed with different concentrations of MgO to prepare high entropy alloys composites. Soft magnetic and wave-absorbing properties of composites characterized and analyzed. The results show that MgO has a role in reducing the total loss of magnetic powder cores. The best soft magnetic performance is obtained when the addition amount is 0.25 wt%, with a total loss of 1455 mW/cm 3 ( f = 1000 kHz, B m = 5mT), and the saturation magnetization strength shows a decreasing trend with the increase of MgO content. Significantly improved wave-absorbing performance in the 2–18 GHz band with the addition of MgO. When the added MgO content is 0.25 wt%, the samples have the best wave-absorbing properties. The thickness is 4.5 mm, the minimum reflection loss is −41.2 dB at 7.3 GHz, the effective absorption bandwidth is 3 GHz (5.6–8.6 GHz), and it has excellent wave-absorbing performance.
研究领域:
材料科学
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电磁学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qingxuan Zhou,Yang Wang,Zhuoqun Han,Jia Liu,Jie Zhao,Wei Chu,Zhicheng Zhao,Jian Li,Zhiqiang Cheng,Ling Li,Futian Liu
Due to the low powder content characteristic of digital light processing in the preparation of ceramic green bodies, significant challenges arise in obtaining high-density, high-performance Si 3 N 4 ceramic. Sintering aids exert a critical influence on the densification and properties of Si 3 N 4 ceramics. To further improve the performance of 3D-printed Si 3 N 4 ceramics, Si 3 N 4 ceramics were fabricated using DLP technology combined with gas pressure sintering employing different ratios of La 2 O 3 -MgO as sintering aids. The ceramic slurries, microstructures, and ceramic performance were studied systematically. The results showed that increasing the proportion of· La 2 O 3 powder enhanced the rheological and curing properties of Si 3 N 4 ceramic slurries. Varying the La 2 O 3 -MgO ratio affected the composition of the liquid phase, leading to differences in the densification and grain growth of Si 3 N 4 ceramics. The average grain size increased with higher ratios of La 2 O 3 -MgO, and reached a maximum value of 0.91 μm with a ratio of 9:1. With the increase of the La 2 O 3 -MgO ratio, the bulk density and shrinkage rate of the ceramics initially increased and then declined. In addition, the flexural strength and fracture toughness of the ceramics peaked at a ratio of 3:7 for La 2 O 3 -MgO, measuring 577 ± 16.28 MPa and 5.84 ± 0.17 MPa m 1/2 , respectively. These results demonstrate that high-performance Si 3 N 4 ceramics can be effectively prepared using DLP technology by adapting the ratio of sintering additives.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
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2024
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IF 2.2
Li Pengfei,Sui Yudong,Jiang Yehua,Zhou Mojin,Wang Zhijie
The effects of MgO addition on the microstructure and mechanical, frictional, and wear properties of zirconia-toughened alumina (ZTA) ceramics were investigated in this study using hot pressure sintering (HP). The addition of trace amounts of MgO led to the refinement of the ceramic grains and an increase in the ceramic density due to the pinning effect of MgO. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results revealed that an MgAl 2 O 4 phase was formed in the ceramics, which also contributed to the refinement of the ceramic grains. Moreover, the addition of MgO promoted the uniformity of the ceramic microstructure. Among the tested composites, the composite with 0.4 wt.% MgO exhibited the most favorable comprehensive properties, including a relative density of 99.61%, hardness of 18.29 GPa, and indentation fracture toughness of 9.15 MPa·m 1/2 , thereby offering the highest resistance to adhesive wear.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
FUEL
·
2025
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IF 7.5
Kande Liu,Sitan Wang,Lishan Zheng,Yuan Fang,Ranran Tao,Naiwang Liu,Fahai Cao,Xuan Meng,Li Shi
As a crucial fine chemical intermediate, the compound 4-TBP holds significant importance in both antioxidant synthesis and the production of various fine chemical products, including resins, flame retardants, surfactants, and ultraviolet absorbers. However, traditional catalysts employed in the production of 4-TBP are plagued by several drawbacks, such as equipment corrosion, environmental contamination, and inadequate thermal stability. In order to overcome these challenges, a series of Hβ-x% MgO catalysts with varying MgO loadings were successfully synthesized using the immersion method. These catalysts were comprehensively characterized through multiple analytical techniques, including XRD, FT-IR, SEM, N 2 adsorption–desorption analysis, ICP-OES, Py-IR, 27 Al and 29 Si MAS NMR and CO 2 -TPD. These materials were subjected to catalytic evaluation through the phenol alkylation process using tert -butyl alcohol as the alkylating agent. Notably, the Hβ-2.5% MgO catalyst demonstrated superior performance, a remarkable selectivity of 88.2% toward 4-TBP production was attained, which represents a 14.7% improvement over the unmodified Hβ zeolite. The study scope was expanded to incorporate methanol as an alkylation agent, consistent reaction rules were observed, which contributes significantly to the understanding of alcohol-mediated phenol alkylation studies.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
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2018
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IF 3.584
Jie Zhang,Lei Wang,Chuang Li,Shaohua Jin,Changhai Liang
Direct selective hydrogenolysis of dibenzofuran (DBF) derived from coal and shale oil to a value-added chemical, ortho-phenylphenol (OPP), with high selectivity (80%) and yield (48%) has been achieved over Pt/MgO at 400 °C and 1.0 MPa by controlling the C–O bond cleavage as well as minimizing the extent of hydrogenation of aromatic rings. Meanwhile, Pt/SiO2, Pt/Al2O3, and Pt/MgO/Al2O3 catalysts were used for the DBF hydrogenolysis and showed lower selectivity for OPP. The influence of reaction parameters has been studied to unveil the optimal reaction conditions. And the phenomenon of OPP dehydrogenation is found over various catalysts for the hydrogenation reaction of OPP. Extensive reactions and catalyst characterizations demonstrated that the OPP selectivity and the dehydrogenation of OPP to DBF follows the order of supports basicity: MgO-900 > MgO > SiO2 > MgO/Al2O3 > Al2O3, which shows that the acid–base properties of supports impact the adsorption and desorption behaviors of DBF and OPP, and results in the disparity of OPP selectivity and the dehydrogenation of OPP. Finally, a plausible reaction pathway and mechanistic understanding are proposed.
研究领域:
催化化学
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能源化学
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DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2017
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IF 2.124
Ren Gao,Huanping Wang,Qingong Zhu,Qinghua Yang,Xingguo Sun,Bingpeng Li,Shiqing Xu,Xianghua Zhang
The glasses of 93.9% ( x SiO 2 - y Al 2 O 3 - z MgO)-5% CaO-1% B 2 O 3 -0.1% Fe 2 O 3 were prepared, and the relationship between mechanical properties and structural stability were characterized by means of Raman spectroscopy and optical band gap values. The glass forming region is found to be x = 50–70%, y = 10–25% and z = 15–32%. As x = 65%, y = 10% and z = 25% (SAM-4), the investigated glass possesses the optimum volume density, oxygen packing density, optical band gap, banding strength , compression strength and compression modulus, which are 2.517 g/cm 3 , 77.047 mol/l, 3.56 eV, 77.04 MPa, 202.74 MPa and 106.70 GPa, respectively. Meanwhile, starting from the representative point of SAM-4 to radiate around, the volume density, oxygen density, Raman intensity and mechanical properties of the glasses are all decreasing constantly, and the optical band gap of the glasses is increasing on the contrary. Moreover, the optical band gap value and Raman spectroscopy of SAM-4 all prove that the number of oxygen bonds in the bridge reach the maximum and the highest structural stability is achieved, which further shows that it is an important reason why its mechanical properties is significantly improved.
研究领域:
材料科学
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玻璃科学
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光谱学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Shixiong Tang,Fang Li,Jidong Liu,Bao Guo,Zenan Tian,Jianhua Lv
The treatment and reuse of polyester wastes have received widespread attention. In this work, MgO/NaY catalysts with different MgO contents were prepared by the incipient-wetness impregnation method and used in the methanolysis of PET for the first time, proposing a convenient and feasible method to solve the plastic recycling crisis. To characterize the surface and structural properties of the prepared MgO/NaY catalysts by EDXRF, BET, XRD, SEM, FT-IR and TEM. The acid-base properties of the catalysts were also characterized by CO 2 -TPD and NH 3 -TPD. The relationship between acid-base and catalytic activity showed that the conversion of PET and the yield of DMT increased with the increase of alkalinity of the catalyst. The results showed that the PET conversion and the DMT yield could reach 99% and 91%, respectively, under the reaction conditions of 200 °C, 30 min, catalyst dosage of 4 wt%, and the mass ratio of methanol to PET of 6 with 21%MgO/NaY as the catalyst. The recyclability of the catalyst was investigated, and the 21%MgO/NaY catalyst still had excellent catalytic activity for the methanolysis of PET after 6 cycles.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
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IF 5.6
Haoxin Lin,Lin Tian,Xiaoyan Liu,Guocheng Wang,Chongchong Xie,Guohua Li,Chao Tian
In order to improve the comprehensive utilization rate of magnesite flotation tailings and solve its accumulation pollution problem. In this work, Mg 2 SiO 4 -MgO refractories were prepared by solid-phase method using magnesite flotation tailings as raw material and Pr 6 O 11 as additive. The adjustment mechanism of Pr 6 O 11 on the intergranular binding phase of Mg 2 SiO 4 -MgO refractories was investigated and the optimal addition amount of Pr 6 O 11 was determined through thermodynamic calculations, DSC test, phase composition test, microstructure observations and physical property tests. The results show that when Pr 6 O 11 is not added, the intergranular binding phase of Mg 2 SiO 4 -MgO refractories is CaO·MgO·SiO 2 . After Pr 6 O 11 is added, Pr 6 O 11 takes advantage of its high reactivity to extract SiO 2 and CaO from the MgO-SiO 2 -CaO system, which is supposed to synthesize CaO·MgO·SiO 2 , and reacts to produce Ca 2 Pr 8 (SiO 4 ) 6 O 2 , which consumes the reactants for synthesizing CaO·MgO·SiO 2 , thus inhibiting the production of CaO·MgO·SiO 2 . Thereby adjust the refractories intergranular binding phase from low melting point CaO·MgO·SiO 2 (melting point:1498°C) to high melting point Ca 2 Pr 8 (SiO 4 ) 6 O 2 (melting point:1780°C), which resulted in the improvement of the refractories's high temperature resistance and thermal shock resistance. At the same time, Pr 6 O 11 can form solid solution with Mg 2 SiO 4 and MgO to promote the sintering densification of the refractories, and the overall performance of the refractories is optimal when the addition amount of Pr 6 O 11 is 2wt%.
研究领域:
材料科学
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无机非金属材料
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产品关联
DOI
高影响因子
Journal of Cleaner Production
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2022
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IF 11.072
Meng Liu,Xiangzhe Yan,Lezhu Su,Hang Dong,Zhan Hu,Yuanqi Peng,Liqian Guan,Junjie Zhang,Zhi Zhou,Yongfa Zhu,Nan Zhou
Pyrolysis technology has been focused on waste plastics for recycling. However, there is rare research for reusing pyrolysis products (carbon nanotubes). Based on pyrolysis technology of waste polypropylene (PP) plastic, carbon nanotube coated Fe–Mo/MgO nanomaterial (CNT@Fe–Mo/MgO) was prepared by chemical vapor deposition to remove Gram-pathogenic bacteria. The addition of Mo and MgO promoted the cracking of PP plastic and the formation of MWCNTs. The as-obtained CNT@Fe–Mo/MgO can stimulate H 2 O/O 2 to produce abundant ·OH, ·O 2 − and 1 O 2 radicals, which probably resulting from the synergistic effect of delocalization of CNTs and REDOX pair of Fe 3 O 4 . Consequently, the removal rate of Escherichia coli and Staphylococcus aureus by CNT@Fe–Mo/MgO composite catalyst can reach 100% within 2h, without the help of any additional energy or active oxidant. At the same time, the material is remarkable stability and reusability with complete removal of pathogens after six cycles. This study not only provides a method for the synthesis of highly effective sterilizers , but also opens up a new direction for the application of functional carbon nanocomposites prepared by pyrolysis of waste plastics.
研究领域:
环境科学
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材料科学
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微生物学
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DOI
高影响因子
Small
·
2023
·Vol. 19
·期 45
·2303405
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IF 13.3
Mengping Liu,Ganbing Zhang,Ruiqi Ming,Xin Fu,Ruiyi Jiang,Lihong Tian,Xiaobo Chen
Defects on metal oxide have attracted extensive attention in photo-/electrocatalytic CO 2 reduction. Herein, porous MgO nanosheets with abundant oxygen vacancies (V o s) and three-coordinated oxygen atoms (O 3c ) at corners are reported, which reconstruct into defective MgCO 3 ·3H 2 O exposing rich surface unsaturated -OH groups and vacancies to initiate photocatalytic CO 2 reduction to CO and CH 4 . In consecutive 7-cycle tests (each run for 6 h) in pure water, CO 2 conversion keeps stable. The total production of CH 4 and CO attains ≈367 µmol g cata −1 h −1 . The selectivity of CH 4 gradually increases from ≈3.1% (1 st run) to ≈24.5% (4 th run) and then remains unchanged under UV-light irradiation. With triethanolamine (3.3 vol.%) as the sacrificial agent, the total production of CO and CH 4 production rapidly increases to ≈28 000 µmol g cata −1 in 2 h reaction. Photoluminescence spectra reveal that V o s induces the formation of donor bands to promote charge carrier seperation. A series of trace spectra and theoretical analysis indicate Mg-V o sites in the derived MgCO 3 ·3H 2 O are active centers, which play a crucial role in modulating CO 2 adsorption and triggering photoreduction reactions. These intriguing results on defective alkaline earth oxides as potential photocatalysts in CO 2 conversion may spur some exciting and novel findings in this field.
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）