Effects of Reaction Temperature and Time on the Aluminothermic Reduction of Magnesia

2012 ◽  
Vol 538-541 ◽  
pp. 2236-2239 ◽  
Author(s):  
Peng Deng ◽  
Yu Qin Liu ◽  
Da Jian Ma ◽  
Hong Wen Ma
Keyword(s):  
Electron Microscopy ◽  
Reaction Temperature ◽  
Energy Dispersive Spectrometry ◽  
Thermal Reduction ◽  
Reduction Ratio ◽  
Aluminothermic Reduction ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The present paper focuses on the experimental investigation of the aluminothermic reduction of magnesia under vacuum condition with the fixed magnesia to aluminum molar ratio of 11:6. The influences of reaction temperature and time on the reduction ratio of magnesia were studied. The chemical composition, phase constitution and morphology of the condensed magnesium and the briquettes after thermal reduction were investigated by X-ray diffraction, scanning electron microscopy equipped with energy dispersive spectrometry. The reduction ratio of magnesia increases with the increase in the reaction temperature and time. The briquettes after thermal reduction at 1050°C-1150°C are mainly composed of the spinel, unreacted magnesia and aluminum. The briquette after 1 hrs thermal reduction at 1200°C contains corundum, magnesium aluminium oxide, trace amount of spinel, unreacted MgO and aluminium.

scholarly journals Analytical study of Buddha sculptures in Jingyin temple of Taiyuan, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

AbstractWith exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

Application of vermiculite and limestone to desulphurization and to the removal of dust during briquette combustion

2003 ◽  
Vol 67 (6) ◽  
pp. 1243-1251 ◽  
Author(s):  
A. Lu ◽  
D. Zhao ◽  
J. Li ◽  
C. Wang ◽  
S. Qin
Keyword(s):  
Electron Microscopy ◽  
Coal Combustion ◽  
Combustion Temperature ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Retention Ratio ◽  
X Ray ◽  
Major Factors ◽  
Chemical Reactant ◽  
Scanning Electron

AbstractSmall domestic cooking furnaces are widely used in China. These cooking furnaces release SO2 gas and dust into the atmosphere and cause serious air pollution. Experiments were conducted to investigate the effects of vermiculite, limestone or CaCO3, and combustion temperature and time on desulphurization and dust removal during briquette combustion in small domestic cooking furnaces. Additives used in the coal are vermiculite, CaCO3 and bentonite. Vermiculite is used for its expansion property to improve the contact between CaCO3 and SO2 and to convey O2 into the interior of briquette; CaCO3 is used as a chemical reactant to react with SO2 to form CaSO4; and bentonite is used to develop briquette strength. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside the briquette, and thus brings enough oxygen for combustion and sulphation reaction. Effective combustion of the original carbon reduces amounts of dust in the fly ash. X-ray diffraction, optical microscopy, and scanning electron microscopy with energy dispersive X-ray analysis show that S exists in the ash only as anhydrite CaSO4, a product of SO2 reacting with CaCO3 and O2. The formation of CaSO4 effectively reduces or eliminates SO2 emission from coal combustion. The major factors controlling S retention are vermiculite, CaCO3 and combustion temperature. The S retention ratio increases with increasing vermiculite amount at 950°C. The S retention ratio also increases with increasing Ca/S molar ratio, and the best Ca/S ratio is 2-3 for most combustion. With 12 g of the original coal, 1 to 2 g of vermiculite, a molar Ca/S ratio of 2.55 by adding CaCO3, and some bentonite, a S retention ratio >65% can be readily achieved. The highest S retention ratio of 97.9% is achieved at 950°C with addition of 2 g of vermiculite, a Ca/S ratio of 2.55 and bentonite.

scholarly journals Hydrothermal synthesis and characteristics of lanthanumdoped pb(Zr₀.₆₅Ti ₀.₃₅)O₃ ceramics

2021 ◽  
Vol 8 (3) ◽  
pp. 14-19
Author(s):  
Thuy Nguyen Thanh ◽  
Tung Nguyen Van ◽  
Hung Nguyen Trong ◽  
Minh Cao Duy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Reaction Temperature ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Influence Of Ph ◽  
Scanning Electron

Lanthanum-doped lead zirconate titanate (PLZT) powders were synthesized using thehydrothermal method. The influence of pH, reaction temperature and time, lanthanum concentration on the formation and characteristics of PLZT were investigated. Obtained powders were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) techniques and a dielectric analyzer. The results showed that           Pb1-xLax(Zr0.65Ti0.35)O3 with x= 0.0 – 0.1 were well formed under conditions: pH≥13, reaction time of 12hrs, reaction temperature of 180oC. Dielectric constant of PLZT is higher than PZT. The grain size of the PLZT is found to be 1–3.5 µm.

Synthesis of Precipitate Calcium Carbonate with Variation Morphology from Limestone by Using Solution Mixing Method

2019 ◽  
Vol 966 ◽  
pp. 200-203
Author(s):  
Zaenal Arifin ◽  
Triwikantoro ◽  
Bintoro Anang Subagyo ◽  
Mochamad Zainuri ◽  
Darminto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Molar Ratio ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
Precipitate Calcium Carbonate ◽  
X Ray ◽  
Mixing Method ◽  
Scanning Electron

Abstract. In this study, the CaCO3 powder has been successfully synthesized by mixing CaCl2 from natural limestone and Na2CO3 in the same molar ratio. The mixing process of solutions was carried out by employing the molar contents of 0.125, 0.25, 0.375 and 0.5M at varying temperatures of 30, 40, 60 and 80ᴼC. The produced CaCO3 microparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The highest content of aragonite phase with morphology rod-like of the samples is around 29 wt%, resulting from the process using solution of 0.125 M at 80 ᴼC. While at 30 ᴼC and 40 ᴼC produced 100 wt% calcite phase.

Experimental Study on Combustion Reaction between Silicon and Nitrogen in Transport Bed

2013 ◽  
Vol 860-863 ◽  
pp. 1374-1377
Author(s):  
Shao Wu Yin ◽  
Li Wang ◽  
Li Ge Tong ◽  
Chuan Ping Liu ◽  
Xing Long Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Combustion Reaction ◽  
X Ray Diffraction ◽  
Amorphous Silicon Nitride ◽  
X Ray ◽  
Scanning Electron

Combustion reaction between silicon powders and nitrogen in transport bed was studied. The reaction temperature ranged from 1523 to 1653 K, and the reaction time ranged from 0 to 2.7 min. The phase compositions, morphologies and chemical composition of the products were analyzed by X-ray diffraction, scanning electron microscopy and O/N determinater, respectively. The experimental results showed, in the case of silicon powders with particle size of 2.2 μm, the conversion rate of silicon was 61.9% at reaction temperature of 1653 K and reaction time of 2.7min, and the products mainly comprised amorphous silicon nitride powders.

Synthesis of Ti3Si0.4Al0.8C1.8 Solid Solution

2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Lattice Parameters ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Scanning Electron

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.

scholarly journals Analytical Study of Buddha Sculptures in Jingyin Temple of Taiyuan, China

2020 ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

Abstract With exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM-EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

Investigation of the weldability of AISI304 and AISI1030 steels welded by friction welding

2020 ◽  
Vol 117 (6) ◽  
pp. 601
Author(s):  
Tanju Teker ◽  
Eyyüp Murat Karakurt ◽  
Murat Özabaci ◽  
Yaşar Güleryüz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Friction Welding ◽  
Rotational Speed ◽  
Fracture Behavior ◽  
Energy Dispersive Spectrometry ◽  
Weld Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this study, the effect of rotational speed on the microstructure and weldability of AISI1030 steel and AISI304 stainless steel welded by friction welding method were investigated experimentally. The weld joints were manufactured with rotational speed (1500, 1600, 1700, 1800, 1900, and 2000 rev/min.), friction pressure (40 MPa), forging pressure (60 MPa), forging time (4 s), and friction time (6 s). After the FW process, the microstructures of the weld interfaces were analyzed by optic microscopy, scanning electron microscopy, energy dispersive spectrometry, elemental mapping, and X-ray diffraction analysis. Moreover, the weld strength was analyzed by tensile test, and the fracture behavior was investigated with scanning electron microscopy. The results indicated that increased rotational speed had a significant effect on the microstructure and weldability.

Effect of Ti and Sb Elements Addition on the Microstructure and Corrosion Resistance of Hot-Dip Galvanized Zn-11Al-3Mg Alloy

2021 ◽  
Vol 1035 ◽  
pp. 630-637
Author(s):  
Hui Jie Sun ◽  
Guo Rong Zhou ◽  
Ming Ming Zhang ◽  
Xue Feng Wang ◽  
Shui Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Energy Dispersive Spectrometry ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Pitting Corrosion Resistance ◽  
Scanning Electron

The effect of Ti and Sb elements addition on the microstructures and corrosion resistance of hot-dip galvanized Zn-11Al-3Mg alloy was investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and Electrochemical workstation, respectively. Results showed that the grain size of the alloy was obviously refined with the addition of Ti and Sb elements, due to Al3Ti phase as the nucleation substrate resulted in the transformation of Al-rich phase from dendrite to petal-like. In addition, the pitting corrosion resistance of the alloy has been significantly enhanced.

Phosphoric Acid Rate Addition Effect in the Hydroxyapatite Synthesis by Neutralization Method

2006 ◽  
Vol 530-531 ◽  
pp. 593-598 ◽  
Author(s):  
D.S. Gouveia ◽  
Ana Helena A. Bressiani ◽  
José Carlos Bressiani
Keyword(s):  
Electron Microscopy ◽  
Heating Rate ◽  
Calcium Phosphates ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
Distilled Water ◽  
X Ray Diffraction ◽  
Vacuum Filtration ◽  
X Ray ◽  
Scanning Electron

Calcium phosphates with different Ca/P molar ratio can be obtained depending the precipitation conditions such as pH and temperature. In this work the effect of the pH’s variation during the H3PO4 addition in the synthesis of hydroxyapatite-HA, (Ca/P molar ratio 1.67) by neutralization method, was studied. The H3PO4 addition’s rate was 1.0, 1.5, 8.0 mL.min-1 and in other experiment the H3PO4 was added at a time. After the addition was completed the pH ranged from 7-12. The suspensions were kept during 24 hours for ripening. The precipitate was separated from the suspension by vacuum filtration, washed with distilled water and dried at 70°C/24h. Afterwards the materials were analyzed by thermogravimetric analysis (TGA) with heating rate of 10°C/min in air. The calcination of the powders was accomplished at 800°C/3h with heating rate of 10°C.min-1. The powders were characterized by X-ray diffraction (XRD), infrared spectrometry (FTIR), specific surface area (BET), and scanning electron microscopy (SEM). The results indicated that the ratio of addition of the acid can influence both the morphology and the formation of the phases (HA and TCP) in the obtained powders.

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