CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Minhao Shen,Renli Fu,Yi Zhang,Kuang Sun,Wei Xu,Yanlin Jiang,Zhe Zhao,Ming Liu
Vat photopolymerized 3D printing technology can be used to fabricate ceramics with complex shapes. However, the extensive use of photosensitive resins as binders is not conducive to achieving crack-free ceramic green parts, especially the Si 3 N 4 ceramics with the weak interlayer bonding. In this work, the influence of different debinding atmosphere on the pyrolysis process of organics in vat photopolymerization 3D printed Si 3 N 4 green parts was investigated. The results showed that the use of 95 vol% N 2 +5 vol% H 2 atmosphere can effectively inhibit the cracking during the debinding process, especially the wall thickness of the 3D printed defect-free Si 3 N 4 green body was successfully increased to 5 mm, and the obtained sintered Si 3 N 4 ceramics exhibited higher true densities and better mechanical properties. The debinding atmospheres proposed in the current work provided additional options of debinding atmosphere for achieving high-performance 3D printed Si 3 N 4 ceramics and are expected to be expanded to other photosensitive slurry systems, with the potential to enable the production of ceramic components with the larger wall thicknesses.
研究领域:
材料科学
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陶瓷制造
·
3D打印技术
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2024
·
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
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2025
·
IF 7.1
Yunyan Wang,Maixin Yu,Yu Liu,Xiaobo Min,Zelong Huang,Cong Peng,Yong Ke,Pingsheng Zeng,Xingwu Lu,Yun Li
At present, lead-containing wastes have increasingly become the raw materials together with primary lead concentrate for lead production to meet the ever-increasing lead demand market. PbSO 4 is the dominant component in the lead-containing wastes, nevertheless, its reaction behavior during lead smelting is not sufficiently investigated. This study investigated PbSO 4 decomposition behaviors and phase transformation mechanisms at oxidizing and reductive atmospheres and various gas flow rates. The investigations reveal that increasing the temperature and decreasing the oxygen partial pressure of the decomposition atmosphere can accelerate PbSO 4 decomposition degree. PbSO 4 decomposition intensity under different atmospheres follows the order of reducing atmosphere > inert atmosphere > oxidizing atmosphere. PbSO 4 decomposition path was identified: at a non-reductive atmosphere, the decomposition of PbSO 4 belongs to a multi-step decomposition process, PbSO 4 gradually decompose into xPbO·PbSO 4 (x = 1, 2, 4 in turn) and finally PbO. At a reductive atmosphere, the multi-step decomposition process was accelerated significantly, at the same time, the reduction decomposition path PbSO 4 → PbS was increasingly dominant with the extension of decomposition time. PbS and Pb were generated successively. Therefore, a suitable reducing atmosphere is suggested to co-smelt PbSO 4 -bearing wastes in primary lead smelting furnace.
研究领域:
冶金学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Qiuping Li,Shaopeng Gu,Liang Yu,Jingmeng Dong,Zerong Duan
Chromium (Cr) slag, a byproduct of steelmaking, is an important recyclable secondary resource. The preparation of Na 2 CrO 4 from Cr slag has the potential to enhance the economic value of the slags and address environmental challenges linked to Cr(VI). This study investigated the heating processes of Cr slag without and with 30 wt.% Na 2 CO 3 under different atmospheres (air and argon) from 30 ℃ to 1400 ℃. The results showed that 30 wt.% Na 2 CO 3 reacted with Cr 2 O 3 and FeCrO 4 , starting to form Na 2 CrO 4 at 915 ℃ in air. When the heating temperature exceeded 1200 °C, Na 2 CrO 4 started to volatilize, which can be collected. Conversely, heating Cr slag with Na 2 CO 3 in argon generated NaCrO 2 without Cr volatilization. This research proposed a green one-step and cost-effective method for Na 2 CrO 4 preparation: Cr slag heated with 30 wt.% Na 2 CO 3 in air to 1400 ℃. It can use the residual heat from steelmaking, contributing to the recovery and utilization of secondary resources.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Zhanshuai Li,Jinsheng Li,Huanyu Zhao,Mengwen Zhang,Pengfei Li,Liang Dong,Lei Wu,Haipeng Ji,Xiwei Qi
A new high-entropy oxide, (Ge 0.2 Mn 0.2 Ti 0.2 Sn 0.2 Mo 0.2 )O 2 with rutile structure, was successfully synthesized using solid-state reaction method. The phase structure of the ceramic samples prepared forming a range of binary to quinary phase with increasing entropy were investigated, and the effects of atmosphere-induction and high-entropy synergistic behavior on the dielectric performance were studied. As the type of the cations increases, the temperature required to form a single rutile structure gradually decreases, while the dielectric properties of the ceramics gradually improved. The dielectric constant of the (Ge 0.2 Mn 0.2 Ti 0.2 Sn 0.2 Mo 0.2 )O 2 high-entropy oxide ceramics sintered in the nitrogen atmosphere at 1350°C is nearly 20 times higher of the ceramics sintered in the air. This significant enhancement can be attributed to the occurrence of two rutile structures and the generation of excessive oxygen vacancies as a result of high-entropy synergistic behavior under the nitrogen sintering atmosphere.
研究领域:
材料科学
·
陶瓷材料
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介电材料
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高熵合金
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Hongyi Huang,Shaoyuan Liu,Zeyu Kang,Yiwen Zhu,Chengbin Zhang,E Xiang,Zhang Lin,Weizhen Liu
Vancomycin fermentation residue (VFR) urgently needs proper treatment due to its complex and hazardous nature. Pyrolysis is a promising treatment method, while the product characteristics of VFR pyrolysis remain unclear. Therefore, the influence of different atmospheres and stepwise pyrolysis (including one-stage reaction in N 2 or CO 2 and two-stage reaction in N 2 ) on pyrolysis behavior, product characteristics, and N/S migration mechanism during VFR pyrolysis were investigated for the first time in this work. The results showed that VFR mainly decomposed at 180–600 °C, forming non-condensable gas, bio-oil, and biochar. The main released gases included CO 2 , H 2 O, NH 3 , HCN, SO 2 , and H 2 S, whereas the N-containing pollutant gas, notably NH 3 , should be focused due to its high emission (>10 %). Bio-oil was rich in N-containing compounds with a content exceeding 46 %, mainly consisting of Indolizne (9.2–11.5 %), 5H-1-Pyrindine (5.0–9.9 %), and Indole (8.4–9.0 %), and 9-Octadecenamide, (Z)- (1.8–10.1 %). Moreover, the effects of different conditions on the product characteristics were as follows: For the one-stage reaction, compared to N 2 , the CO 2 atmosphere promoted the formation of alcohols (intended product, increasing 2.2–14.6 %), whereas the two-stage reaction in N 2 inhibited alcohol production (decreasing 1.1–2.5 %). At CO 2 condition, the harmless temperature of VFR reduced from 600 °C (pyrolysis in N 2 ) to 400 °C. Both CO 2 (increasing 0.6–1.5 %) and the two-stage reaction in N 2 (increasing 0.4–1.0 %) retained more N in the solid. Kinetics showed that the pyrolysis process of VFR conformed to diffusion models and reaction order models (F2/D1/F3/D1 for N 2 and F2/D2/F3/D1 for CO 2 ). The VFR transformed to the chemicals and fuels mainly through the deamination, desulfurization, dehydration, decarboxylation, and dehydrogenation reactions. This work provides guidance for harmless disposal and resource utilization during VFR pyrolysis.
研究领域:
环境科学
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生物工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ISIJ INTERNATIONAL
·
2017
·Vol. 57
·期 1
·62-67
·
IF 1.11
Zijian Su,Yuanbo Zhang,Yingming Chen,Guanghui Li,Tao Jiang
A considerable amount of works were focused on the formation mechanism of calcium ferrite phases during the iron ore sintering process, especially under various O2 content atmospheres at temperatures higher than 1100°C. But little attention has been paid on reactions between CaO and iron oxides in CO–CO2 atmospheres at lower temperatures. In this study, the solid state reaction mechanisms between CaO and Fe3O4 under CO–CO2 atmospheres at 800°C–1100°C were revealed by using XRD, VSM, etc. The results indicated that Ca2Fe2O5 was easily formed under 5–50 vol% CO/(CO+CO2) atmosphere above 850°C via the reaction of 6CaO + 2Fe3O4 +CO2 = 3Ca2Fe2O5 + CO and the reaction would be promoted with increasing the roasting temperature. In the CO–CO2 atmosphere, Fe3O4 is easily oxidized to Fe2O3 in the presence of CaO because CO2 components act as oxidative medium for the oxidation of Fe2+ to Fe3+.
研究领域:
冶金学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Qiang Xian,Xin Xiao,Jiaping Yu,Yi Gan,Li Chen,Xinmiao He,Enchao Wang,Hui Dan,Lin Zhu,Yi Ding,Tao Duan
The immobilization of iodine waste suffers from serious iodine loss during heat treatment. Herein, we reported on the high iodine retention immobilization of simulated radioiodine-contaminated Bi0–SiO2 sorbent in B–Bi–Zn oxide glass using Bi2O3 as a stabilizer under a N2 atmosphere. The effects of the Bi2O3 content and sintering atmosphere on the iodine immobilization behaviors (iodine retention ratio, phase composition, microstructure, and chemical stability) were investigated. It was found that the decomposition of BiI3 was prevented by adding Bi2O3 and sintering in a N2 atmosphere. The iodine retention ratio in the obtained glass waste form was significantly enhanced with increasing Bi2O3 content and sintering in the N2 atmosphere due to the synergistic effect. The achieved record-high iodine retention (92.22 ± 2.6%) was much higher than that of conventional heat treatment route (18.01 ± 3.5%). The results demonstrated that iodine was effectively immobilized through the formation of stable BixOyI (Bi5O7I and BiOI). Furthermore, the obtained iodine waste form exhibited excellent compactness and chemical stability. Owing to its high iodine retention ratio, this route can be employed to effectively immobilize radioactive iodine.
研究领域:
材料科学
·
核废料管理
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Xiao-Li Zhou,Pin-Jing He,Wei Peng,Fan Lü,Li-Ming Shao,Hua Zhang
Pyrolysis of plastics is a promising technique towards high-value utilization and solvent-free treatment of plastic waste. However, low product selectivity and broad product distribution may restrict the application of plastic pyrolysis. In this study, polyolefins and polystyrene (PS) were converted into methane and carbon spheres through pyrolysis under autogenic atmosphere (AAP). To elucidate the product evolution and reaction mechanism of AAP, product distributions, compositions and properties at 450–700 °C were investigated. At 450 °C, polyolefins were converted into 89.3–96.91 wt% pyrolysis oil ; PS was converted into 88.4 wt% of pyrolysis oil, 2.3 wt% of gas and 9.3 wt% of char. As the increase of temperature, the yields of methane and pyrolysis char increased significantly. At 700 °C, the yields of pyrolysis chars were as high as ~45 wt% and 74.1 wt% for polyolefins and PS, respectively, and the rest products was mainly pyrolysis gas with less than 1 wt% of pyrolysis oil. Pyrolysis chars were well carbonized spheres with diameters of 2 − 8 µm. Pyrolysis gas contained 93.83–95.74 vol% of methane, and possessed higher heating values of 35.8–36.2 MJ m −3 . The pyrolysis products with high purity and narrow distribution can be attributed to the enhancement of AAP on the secondary reactions of primary decomposition products, such as cracking, hydrogenation, aromatization and condensation .
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Haidong Chen,Feng Zhang,Xianwen Sun,Weifeng Zhang,Guoqiang Li
We systematically investigated the impact of reaction atmosphere on the Pt cocatalyst photodeposition and hydrogen evolution . A long induction period which is hardly found in close-system appears in the presence of oxygen, and is affected by the concentration of chloroplatinic acid. The Pt cocatalyst is metal state and contributes to the electronic states near Fermi level judging from the valence band X-ray photoelectron spectrum. The cocatalyst metal Pt will reduce the surface photovoltage signals due to the metal feature. The hydrogen evolution rate increased and reached a platform with increasing the Pt coverage on the surface of photocatalyst which is characterized by the Pt:Ti atomic ratio.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Chenglong Wang,Luchao Ren,Zixin Zhang,Hui Peng,Cuncheng Li,Panpan Lyu,Qingyang Du,Mingwei Zhang
A dual-modification strategy combining (Li 0.5 Bi 0.5 ) 2+ substitution and BaCu(B 2 O 5 )/LiF atmosphere-assisted sintering was developed to reduce the sintering temperature of MgGa 2 O 4 ceramic. The strategy achieved a 360 °C reduction in sintering temperature (from 1610 to 1250 °C) while maintaining a high performance. The optimal sample (Li 0.5 Bi 0.5 ) x Mg 1- x Ga 2 O 4 ( x = 0.02) exhibited ε r = 9.41, Q × f = 127,159 GHz, and τ f = -39.6 ppm/°C. XRD and Rietveld refinement confirmed that the spinel structure was preserved upon doping, alongside a lattice expansion. Consistent with the enhanced Q × f , a Raman spectroscopy analysis revealed a narrowing of the T 2 g mode, indicating an improved structural ordering. Furthermore, τ f was improved to −39.6 ppm/°C, directly related to the induced lattice distortion and expansion. The enhanced performance was attributed to the synergistic effects of composite ion doping and atmosphere-assisted sintering. The former modified the intrinsic structure and polarization characteristics, while the latter facilitated the densification at lower temperatures.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 12
·2753
·
IF 4.2
Yongzhen Gao,Wenjing Yi,Jingyi Yang,Kai Jiang,Tao Yang,Zhihan Li,Meng Zhang,Zhongyi Liu,Benlai Wu
The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3catalyst calcined in the N2atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+and Cu0species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts.
研究领域:
催化化学
·
能源化学
✓ 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）