POWDER TECHNOLOGY
·
2024
·
IF 4.5
Lei Wang,Meijun Wang,Yuchao Zou,Xiahui Gui
Amorphous silica has been recently recognized for its adverse effects on copper flotation, but its impact remains poorly understood. This study investigates the effects of varying amorphous silica content on the kinetics and selectivity of copper flotation. Results show a significant reduction in chalcopyrite from approximately 99 % to 86 % with increasing amorphous silica content, attributed to increased pulp viscosity and slowed flotation kinetics. The classical first-order kinetic model provided the best fit for the flotation kinetics data, revealing that higher amorphous silica content prolongs the time required to achieve ultimate recovery. Results also show that amorphous silica deteriorated flotation selectivity and increased gangue recovery via entrainment, with complex variations depending on amorphous silica content. A small amount of amorphous silica was identified to significantly impair flotation kinetics and selectivity, leading to a deterioration in overall flotation performance.
研究领域:
矿物加工工程
·
冶金工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Chonghe Xu,Lin Wang,Zhichao Yu,Pinghui Ge,Tingting Li,Xuetao Yue,Xinqiang Wang
This paper reports a facile electrospinning method to synthesize aluminosilicate fibers by using aluminum chloride hexahydrate as single aluminum precursor, which contains no harmful or hazardous chemicals in the precursor sol. The results of Fourier transform infrared, X-ray diffraction, simultaneous thermogravimetry and differential scanning calorimetry show that the sols are diphasic. The thermal decomposition behavior, crystallization process and microstructure of the fibers are discussed in detail. The main components of aluminosilicate fibers heat-treated at 1200 °C are mullite (Al 6 Si 2 O 13 ), alumina (α-Al 2 O 3 ) and amorphous silica , while the alumina phase disappears when the molar ratio of Si to Al is below 1.5. The diameter and microstructure of fibers with different Si/Al molar ratios are obviously different, which is related to the large difference in conductivity of spinning sols. Bulk fibers and fibrous mats with good flexibility can be easily obtained by using alternative collectors. The tensile strength of the fibrous mats can reach 2.63 MPa and 1.52 MPa after heat-treated at 1000 °C and 1200 °C, respectively. The aluminosilicate fibers fabricated in this work has a noticeable potential in high temperature fields and related applications.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
FLAVOUR AND FRAGRANCE JOURNAL
·
2021
·Vol. 36
·期 4
·457-464
·
IF 2.576
Yu Kang Zhang,Ling Gao,Jie Ling Chen,Ying Hong,Wei-Jian Shen,Ying Wang,Jian Hua Zhu
A new way of controllable releasing menthol with amorphous silica is reported for the first time. Porous silica adsorbed menthol in 373-413 K and then was covered with cellulose acetate film to form a carrier-embedded menthol. The sealed menthol would be released at elevated temperatures once the cover fractured. Here, the influence of temperature and nature of sorbent on the adsorption of menthol along with the covering manner were investigated carefully, and the thermal release of menthol was studied with headspace gas chromatography (HS-GC) method. Silica adsorbed about 400 mg g −1 of menthol at the optimal adsorption conditions and released most of them at about 473 K. Preliminary application in non-combustible cigarette proven the feasibility of thermal release of menthol with the covered silica carrier.
研究领域:
材料科学
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化学工程
·
分析化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Long Chen,Zhengjuan Wang,Song Hu,Xianpeng Qin,Zhenhai Xue,Guohong Zhou,Shiwei Wang
Infrared transparent mullite ceramics were fabricated by solid-state reactive sintering under vacuum without pressure. High purity α-alumina and amorphous silica (molar ratio, 63: 37) powders were used as raw materials. The densification process and mullitization process of the mixed powders were investigated and compared with the sintering of mullite powder. As the sintering temperature increased to 1400 °C, mullite formed and silica transformed into cristobalite. Cristobalite disappeared at 1600 °C and α-alumina did at 1650 °C. However, α-alumina precipitated when the temperature increased to 1750 °C. For the sintering of mullite powder, shrinkage happened at 1400 °C. While, shrinkage almost finished for the reactive sintering of alumina and silica. When reactive sintered at 1780 °C, the transmittance of the mullite ceramics was the highest, which was 65% at 4.1 μm. The method used in this work is promising for the preparation of large and complex shaped transparent mullite ceramics.
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
ENERGY & FUELS
·
2020
·
IF 3.421
Qinglin Li,Hairong Zhang,Fen Peng,Can Wang,Hailong Li,Lian Xiong,Haijun Guo,Xinde Chen
Biogas upgrading technology is important for increasing the heating value of biogas through selective adsorption of CO2. In this work, a series of new monoethanolamine (MEA)-modified attapulgite (ATP)-based amorphous silica (a-SiO2) sorbents with a large surface area and oxygen vacancies were prepared by the impregnation method for the selective adsorption of CO2 from simulated biogas. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption results indicated that MEA with suitable loading was anchored onto the external surface of a-SiO2, which could improve the dispersion of rodlike fibers of ATP. MEA loading and reaction temperature optimization experiments showed that the 50MEA/a-SiO2 sorbent achieved the highest CO2 adsorption capacity of 2.14 mmol/g with an amine efficiency of 5.22 mmol/g and 0.32 mol/mol at 60 °C. Furthermore, only a 6.3 and 4.7% reduction of CO2 adsorption capacity occurred after five adsorption–desorption cycles under simulated biogas at 30 and 60 °C adsorption, respectively, indicating that the sorbent has good regenerability and thermal stability. The chemical adsorption was proved to be the CO2 adsorption mechanism of MEA-modified ATP-based a-SiO2 sorbent by XRD and FTIR testing.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Carbon Energy
·
2025
·
IF 24.2
Chang Guo,Xin-Yu Fan,Mengting Liu,Shao-Wen Xu,Guang-Xu Wei,Zhen-Bang Chen,Zhao-Kun Guan,Yao Xiao,Hanshen Xin,Peng-Fei Wang
Although sodium-ion batteries (SIBs) are competitive for large-scale electrical energy storage, the high-voltage instability of the cathode–electrolyte interphase (CEI) formed on the cathode surface results in the dissolution of the transition metal (TM) and the sluggish interfacial electrochemical reaction kinetics, which deteriorates both the energy density and the cycle life of the SIBs. Herein, we propose a surface modification strategy to reconstruct the interphase of P2-type Na 0.7 Li 0.03 Mg 0.03 Ni 0.27 Mn 0.6 Ti 0.07 O 2 (LM′NMT) cathode with amorphous SiO 2 (denote as SiO 2 @LM′NMT) by a wet chemical method. This approach facilitates the reconfiguration of a more stable, inorganic-rich CEI due to enhanced adsorption catalysis of an amorphous coating with ample defects, resulting in improved Na + transport kinetics and inhibition of subsequent side reactions, TM dissolution, and structural degradation. As a result, the modified SiO 2 @LM′NMT-5 cathode exhibits an impressive capacity of 131.6 mAh g −1 at 0.1 C and maintains exceptional cycling stability, with 91.7% capacity retention after 150 cycles at 1 C within the voltage window of 2.2 to 4.4 V. This study grasps insights into optimizing the CEI to push forward practical application of SIBs under high voltages.
研究领域:
材料科学
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电化学
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能源存储
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纳米材料
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界面化学
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产品关联
DOI
高影响因子
ChemPlusChem
·
2022
·Vol. 87
·期 3
·e202100494
·
IF 3.21
Liangqi Chen,Tingting Xue,Hualei Hu,Chunlin Chen,Dazhi Wang,Weijie Cai,Yong Yang,Jian Zhang
Graphical Efficient etherification of 2,5-bis(hydroxymethyl)furan (BHMF) to 2,5-bis(propoxymethyl)furan (BPMF) was achieved by using low-cost amorphous silica-aluminas (ASA) catalysts in a fixed-bed reactor. Benefiting from the appropriate acidity and better mass transfer, ASA-30 catalyst exhibited superior performance with a maximum BPMF yield of 85.1 %. This work provides a useful reference to develop the efficient ASA catalysts for the large-scale production of BPMF. The efficient etherification of 2,5-bis(hydroxymethyl)furan (BHMF) to 2,5-bis(propoxymethyl)furan (BPMF) was achieved by using low-cost amorphous silica-aluminas (ASA) catalysts in a fixed-bed reactor. A considerable yield of BPMF up to 85.1 % was obtained over ASA-30 catalyst under the reaction conditions of 140 °C, 2.0 MPa of N 2 , and 0.015 h −1 of WHSV. The excellent performance of ASA-30 catalyst could be attributed to the relatively stronger acidity (>375 °C) and larger mesoporous size (6 nm), thereby facilitating the conversion of BHMF to BPMF. In addition, the lower ratio of Brønsted/Lewis acid sites for ASA catalyst was found to efficiently suppress the occurrence of side reactions.
研究领域:
化学工程
·
催化化学
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DOI
PubMed
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Yu Xue,Taiyue Chen,Xin Zhao,Jiaxiang Liu
Wet pre-carbonation of steel slag is an important solution to the steel slag soundness problem. This method, however, can consume a significant amount of silicate phase in steel slag. To address this issue, it is proposed that the consumption of calcium silicate can be reduced while the hydration performance of steel slag can be improved by adding acidic amino acids into the wet carbonation of steel slag. β-C 2 S is the main cementitious component in steel slag. Synthetized β-C 2 S was used to simulate the reaction mechanism of steel slag during carbonation and to study the role of acidic amino acids in carbonation. The carbonation products were characterized by XRD , FT-IR, TG-DTG, and SEM. The results demonstrated that without the addition of acidic amino acids, the carbonation degree of β-C 2 S reaching the maximum at 1 h under the experimental conditions. Calcite and amorphous silica was formed as a result of the carbonation of β-C 2 S. The final carbonation degree was lower after adding higher concentrations (0.1 mol/L) of acidic amino acids than before. Higher concentrations of acidic amino acids increased the content of metastable CaCO 3 , primarily vaterite. Acidic amino acids were added in the pre-carbonation of steel slag, then the steel slag was mixed with cement to prepare cementitious materials . The cementitious materials’ 28-day compressive strength was higher than without amino acids, and the maximum of strength increased by 9.45 % compared to that without amino acids. Whether amino acids were added or not, the boiling expansion value decreased to 0 after 1 h of carbonation, indicating that the carbonation reaction improved the soundness of cementitious materials.
研究领域:
材料科学
·
环境工程
·
化学工程
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产品关联
DOI
高影响因子
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