Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Funian Han,Liang Yu,Guanghua Wen,Jun Guo,Chunhua Ran,Shaopeng Gu
In this study, the effect of Na 2 O on the sintering and melting behavior of representative CaO-SiO 2 -CaF 2 slag were synthetically investigated by TG-DSC, DIL, XRD, SEM, XPS, and BET. As expected, most shrinkage of CaO-SiO 2 -CaF 2 slags with and without Na 2 O during the sintering process originated from solid-phase sintering, and the formation temperature of cuspidine as the sintering phase was reduced by Na 2 O to 550 °C. While Na 2 O also transformed Ca 4 Si 2 O 7 F 2 to Ca 2 NaSiO 4 F at 650 °C–880 °C and caused unexpected volume expansion, owing to increased cell volume and corresponding pore expansion. Moreover, Na 2 O reduced the melting point of CaO-SiO 2 -CaF 2 slag and promoted the volatilization of fluoride by changing the final phase before melting.
研究领域:
材料科学
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冶金工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2024
·
IF 2.8
Yang Li,Fen Luo,Jiahong Wang,Yu Gao,Gangchuan Ji,Xirui Lu
This study used a ternary Na 2 O-B 2 O 3 -SiO 2 matrix to simulate the immobilization of complex TRPO waste. The study investigated the relationship between the solidified bodies with different TRPO waste contents and their solid solubility, FT-IR, Vickers hardness, and density. The study found that the maximum amount of TRPO waste that can be immobilized in the Na 2 O-B 2 O 3 -SiO 2 matrix was 20 wt .%. When the TRPO waste content ranged from 5-15 wt .%, it was primarily immobilized in the glassy phase. When the TRPO waste content exceeded 20 wt .%, the crystalline phases NdBO 3 and Na 3 Nd(BO 3 ) 2 , which contain the main waste element Nd appeared. Samples containing 20 wt .% TRPO waste resulted in leaching of 10 -6 g·m -2 ·d -1 . The presence of NdBO 3 and Na 3 Nd(BO 3 ) 2 crystals resulted in a decrease in the Vickers hardness and density of the samples. The highest values for Vickers hardness and density were 6.77 GPa and 2.7 g -1 cm -3 , respectively. The borosilicate matrix utilized in this study has proven to be an effective immobilization of complex TRPO wastes and holds promise as a treatment matrix for TRPO wastes.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Sulong Geng,Zhanguo Zhang,Junjie Li,Jianguo Qian,Jiao Liu,Jian Yu,Guangwen Xu
Catalyst samples for CH 4 decomposition were prepared from red mud (RM) by an acid-leaching neutralization precipitation approach. Water-washing the resultant precipitates multiple times, followed by drying at 105 °C and calcination at 500 °C, resulted in a threshold of residual Na 2 O, equivalent to 96% Na 2 O removal. Drying the precipitate at a higher temperature of 200 °C, followed by repeated water washing, provided a deeper Na 2 O removal of 99% and made the resultant samples more active for the targeted reaction. Subsequently, four catalyst samples with a simulated red mud composition and NaOH contents from 0 to 0.3 wt% were prepared and the catalytic test results revealed that the Na 2 O remaining in the RM-derived catalysts did not only inhibit their activation in CH 4 but also lower their maximal activities for CH 4 decomposition. Finally, two catalysts with the same simulated red mud composition and their Na impregnated respectively on Fe 2 O 3 and a mixture support of Al 2 O 3 -SiO 2 -TiO 2 were prepared and tested to explore the effect of Na distribution on the activation behavior of RM-derived catalysts for CH 4 decomposition. The activity testing results showed that it was the Na residual dispersed on iron oxides in the RM-derived samples to significantly inhibit the activation of CH 4 decomposition.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Yunhao Xi,Nengwu Zhu,Junlin Huang,Xiang Li,Weiqing Shen,Pingxiao Wu
The pollution of heavy metals and chlorine salts widely exists in solid/hazardous waste, while the stable heavy metal silicates limit the heavy metals removal. This work proposed mechanism of Na 2 O induced stable heavy metal silicates phase transformation and glass network depolymerization to promote heavy metals chlorination volatilization. Medical waste incineration slag (MWI S) containing heavy metal silicates was used as typical sample. Compared with the control, Cu and Zn volatilization efficiencies sharply increased from 77.54% to 92.22% and 18.70% to 93.82% at 3% Na 2 CO 3 , 1200 °C, 40 min. It showed that Na 2 O successfully induced phase transformation from stable Zn 2 SiO 4 and CuSiO 3 to ZnO and CuO easy to react with chloride by destroying the Si–O of Zn–O–Si and Cu–O–Si, respectively. Meanwhile, Na 2 O effectively destructed Si–O bond to depolymerize the glass network, resulting in the percentage of Q 0 and Q 1 increase from 25.14% to 38.29%, reducing melt viscosity and improvement of volatilization environment to form bigger bubbles. Medical waste incineration fly ash (MWI FA) was applied as Na source to further verify that the mechanism was significantly enhance Cu and Zn volatilization efficiencies. This study provided new method to reduce heavy metal residues in glass products prepared by melting treatment of solid/hazardous wastes.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2024
·Vol. 17
·期 13
·3172
·
IF 3
Maierhaba Abudoureheman,Lanzhen He,Kunpeng Liu,Bo Wei,Jia Lv,Jianjiang Wang,Quan Zhu
The contents of alkali and alkaline earth metals are higher in Zhundong coal, and there are serious problems of slagging and fouling during the combustion process. Therefore, it is of great significance to reveal the mechanism of slagging and fouling in the boiler of Zhundong coal. In this paper, first-principle calculations based on density functional theory are used to study the competition mechanism of alkaline metal oxides during the combustion process in Zhundong coal by establishing the Na2O(110)/CaO(100)-SiO2(100) double-layer interface model. The results show that the bond lengths of the surface of Na2O(110) and CaO(100) with SiO2(100) after adsorption were generally lengthened and the value of bond population became smaller, which formed a stable binding energy during the reaction. The electron loss of Na is 0.05 e, the electron loss of Ca is 0.03 e, and the electron loss of Na2O is greater than that of CaO. The charge transfer on the surface of Na2O with SiO2is obviously higher than that of CaO and the orbital hybridization on the surface of CaO with SiO2is weaker than that on the surfaces of Na2O with SiO2. Na2O is easier to react with SiO2than CaO. The adsorption energies on the surface of Na2O and CaO with SiO2are −5.56 eV and −0.72 eV, respectively. The adsorption energy of Na2O is higher than that of CaO, indicating that Na2O is more prone to adsorption reactions and formation of Na-containing minerals and other minerals, resulting in more serious slagging. In addition, the XRD analyses at different temperatures showed that Na-containing compounds appeared before Ca-containing ones, and the reaction activity of Na2O is stronger than that of CaO in the reaction process. The experimental results have good agreement with the calculation results. This provides strong evidence to reveal the slagging and fouling of Zhundong coal.
研究领域:
能源科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Zhe Wang,Liang Yu,Guanghua Wen,Feng Liu,Fanmao Wang,Mansoor Barati
Volatilization of fluorides is a common phenomenon and an environmental concern in metallurgy, welding, glass, and other industries. In order to understand the effect of Na 2 O on the volatilization behavior of fluorides in molten slags, thermogravimetric analysis together with molecular dynamic (MD) simulation was employed in the present study. The MD simulation results are consistent with the thermogravimetric analysis (TGA). That is, the increase of Na 2 O promotes the volatilization of fluoride. Investigation of melt microstructure showed that the diffusion of Na + plays a key role in the volatilization of fluoride. The main contributing microstructural factors to the diffusion coefficient of Na + are the extent of polymerization in Si O and Ca F networks and the Na F clustering. Collectively, this research offered a thorough understanding of the microstructure and process of fluorine volatilization in molten slags.
研究领域:
冶金学
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材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2021
·Vol. 28
·期 11
·1868-1874
·
IF 2.232
Xiong Shan-xia,Kuang Jian-lei,Zheng Qian-fang,Xiao Ting,Liu Wen-xiu,Wang Qi,Jiang Peng,Cao Wen-bin
Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human health. In this study, inorganic aluminosilicate coatings prepared by combining metakaolin, silica fume, NaOH, and H 2 O were applied to the surfaces of wood-based panels to obstruct formaldehyde release. The Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of coatings. Results showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to 2.2. This value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of polymerization. As the H 2 O/Na 2 O molar ratio was increased from 12 to 15, the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance rate. When the Si/Al, Na/Al, and H 2 O/Na 2 O molar ratios were 2.2, 1.2, and 12, respectively, the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.
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
·
2014
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IF 2.726
Chenglong Zhang,Weidong Xiang,Hongyan Luo,Haitao Liu,Xiaojuan Liang,Xin Ma,Lang Pei,Zhaoping Chen,Jinsong Li,Haihong Gao,Li Ma
Lead-nanoparticles-doped Na 2 O–B 2 O 3 –SiO 2 (NBS) glass was prepared by sol–gel and atmosphere control methods. The formation mechanism and the microstructure of the specimens were investigated by differential thermal analysis and thermal gravimeter, X-ray diffraction, transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, and nitrogen adsorption measurements, respectively. The linear and nonlinear optical properties of the glass were analyzed by UV/VIS/NIR spectrophotometry and Z -scan technology. The results showed that the Pb nanoparticles in spherical shape with the average particle size about 18.9 nm belong to cubic crystal system and have good crystallinity and dispersibility in the glass matrix as well as exhibit excellent nonlinear optical properties. The specimen has a high linear optical transmittance, and little absorption peaks appear in the examined wavelength range. The third-order optical nonlinear parameters calculated are γ of 1.67 × 10 −16 m 2 /W, β of 7.02 × 10 −11 m/W, and χ (3) of 2.61 × 10 −17 m 2 /W 2 .
研究领域:
材料科学
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光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2023
·
IF 3.6
Funian Han,Shaopeng Gu,Liang Yu,Youyu Lu,Lu Zhang,Jiaqi Jia,Jingmeng Dong
The boron emission into air and water during the use of fluorine-free mold flux containing boron was systematically investigated to evaluate the corresponding environmental impacts. Unexpectedly, boron in mold flux was volatilized in the form of NaBO 2 particulate matter as Na 2 O was added to mold flux. Besides, boron remained in the used mold flux residue was found to be linearly released into leachate continuously, and Na + existed in the borosilicate network accelerated the hydrolysis of the network and the dissolution of boron by increasing no-bridging oxygen and converting BO 4 groups into fragile BO 3 groups. Considering the negative effect of Na 2 O on the stabilization of boron in mold flux, limiting the addition of Na 2 O in fluorine-free mold flux containing boron will further minimize the pollution originating from the use of mold flux.
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 THE AMERICAN CERAMIC SOCIETY
·
2020
·Vol. 104
·期 2
·785-792
·
IF 3.502
Jinhua Zhang,Si Xiong,Jingran Wang,Yue’e Ni,Changming Ke
Phase pure and nano-sized hafnium diboride (HfB 2 ) fine powder was prepared via a novel sustainable silicothermic route at 1100°C from inexpensive raw materials HfO 2 , Na 2 B 4 O 7 and Si. By introducing sodium oxysalts as source of Na 2 O into the batch mixtures, the SiO 2 / Na 2 O modulus in the melt were reduced from 5:1 to 2:1, and the original water-insoluble byproduct SiO 2 was taken by the melt at test temperature and converted into water soluble sodium silicate (Na 2 Si 2 O 5 ) which was easily removed from the reacted mass via simple hot water washing. Consequently, the aqua sodium silicate could be readily recycled and used as a precursor for preparing many other valuable materials due to absence of foreign salts (eg halides, especially in the molten salt-assisted synthesis process) in the synthesis process, and the relevant environmental concerns could be alleviated. Using excessive amount of 20 wt% Si and 15 wt% Na 2 B 4 O 7 as compensation for the evaporation loss of silicon, in the form of SiO (g), and B 2 O 3 in the reduction process, a high reaction extent was achieved and HfO 2 and Na 2 B 4 O 7 were completely converted into HfB 2 at 1100°C.
研究领域:
材料科学
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化学工程
·
可持续化学
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2021
·
IF 3.531
Xianying Shao,Yuebo Hu,Yujun Zhao,Shunwei Chen,Lei Liu,Jinmiao Chen,Junhao Li
Mineralizers can efficiently promote the transition of barium aluminosilicate (BaAl 2 Si 2 O 8 , BAS) from hexacelsian to celsian (H-M). However, the detailed mechanism regarding the phase transformation of BAS is still unclear, especially in different glass systems. Herein we systematically studied the crystallization behaviors of SiO 2 -Al 2 O 3 -BaF 2 glass in supercooled oxyfluoride aluminosilicate liquids with increasing Na 2 O concentration, and the influence of crystal phases precipitated from the precursor glass on the dielectric properties of oxyfluoride aluminosilicate glass ceramics was analyzed. We observed that the high addition of Na 2 O promoted no transformation of H-M, but resulted in the precipitation of second phases (e.g., NaAlSi 2 O 6 , Ba 3 AlF 9 ). Our results provide guidance for designing glass ceramics containing celsian (Monoclinic BAS) nanocrystals with superior thermodynamically stable and dielectric characters.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Jiadong Li,Xudong Zhao,Weiwei Li,Ping Lu,Mengling Xia,Xianghua Zhang,Yinsheng Xu
The terbium (Tb) ions doped magneto-optical glasses have attracted significant attention due to their high Verdet constant and excellent optical properties . In the Tb ions doped glass, +3 and + 4 valence states of Tb ions coexisted. However, only the +3 valence is favorable for magneto-optical performance. This study proposed a strategy to increase the concentration of Tb 3+ ions ( C Tb 3+ ) in the glass. The high optical basicity Na 2 O is beneficial for enhancing the Verdet constant. The lower melting temperature suppresses the oxidation of the Tb 3+ to Tb 4+ , leading to the increase of C Tb 3+ . As a result, the Verdet constant at 650 nm was achieved as high as 78.6 rad/(T·m), representing a 42.8 % improvement compared to glasses melted at 1450 °C. This approach avoids glass crystallization at high concentrations of Tb doping and provides a new solution for preparing high-performance magneto-optical glasses.
研究领域:
材料科学
·
光学材料
·
磁光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）