scholarly journals Influence of Sintering Temperature of Kaolin, Slag, and Fly Ash Geopolymers on the Microstructure, Phase Analysis, and Electrical Conductivity

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2213
Author(s):  
Nur Nadiah Izzati Zulkifli ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Anna Przybył ◽  
Paweł Pietrusiewicz ◽  
Mohd Arif Anuar Mohd Salleh ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Fly Ash ◽  
Synchrotron Radiation ◽  
Sintering Temperature ◽  
Element Distribution ◽  
Surface Microstructure ◽  
High Concentration ◽  
X Ray ◽  
Surface Densification ◽  
Microstructural Element

This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10−4 Ωm−1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.

Effect of Sintering Temperature on Silver-Copper Nanopaste as High Temperature Die Attach Material

2013 ◽  
Vol 795 ◽  
pp. 47-50 ◽  
Author(s):  
Kim Seah Tan ◽  
Kuan Yew Cheong
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Sintering Temperature ◽  
Grain Structure ◽  
Binder System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silver Copper ◽  
Die Attach ◽  
Scanning Electron

A novel stencil-printable silver-copper (Ag-Cu) nanopaste that serves as an alternative high temperature die attach material was introduced in this study. The nanopaste was made by mixing 50 nm-sized of Ag and Cu particles with an organic binder system. Sintering temperatures, up to 450°C, were used to sinter nanopaste in air and its post sintered properties were investigated. The viscosity of nanopaste was 350,000 cps and it demonstrated a shear thinning behavior. Scanning electron microscope revealed the change of grain structure with the change in the sintering temperature. Formations of Ag97Cu3 and Ag1Cu99 compounds after sintering were confirmed with X-ray diffraction; and the electrical conductivity of the sintered nanopaste was increased with the increase of the sintering temperature. The study concluded 380°C was the optimum sintering temperature to form a well sintered nanopaste.

Synthesis and Ionic Conductivity of KAlSi3O8

2016 ◽  
Vol 698 ◽  
pp. 8-12 ◽  
Author(s):  
Shinichi Furusawa ◽  
Yohei Minami
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Solid Phase ◽  
Ionic Transport ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray

In this study, KAlSi3O8 was synthesized by a solid-phase reaction at 900, 1000 and 1100 °C, using K2CO3, Al2O3 and SiO2 as the starting materials. The powder X-ray diffraction profile of the compound thus prepared was confirmed to contain a mixture of crystalline and glass phases. In addition, a higher sintering temperature of greater than 1000 °C possibly led to the decrease in the crystalline phase. From the temperature dependence of dc conductivity, activation energies for ionic transport were estimated to be 0.79–0.84 eV. The frequency-dependence of the real part of electrical conductivity suggests that the mechanism of ionic transport in the dispersion region possibly depends on the crystallinity of KAlSi3O8.

Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence

2004 ◽  
Vol 59 (2) ◽  
pp. 255-260 ◽  
Author(s):  
N.Q. Liu ◽  
F. Zhang ◽  
X.F. Wang ◽  
Z.Y. Zhang ◽  
Z.F. Chai ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Element Distribution ◽  
X Ray ◽  
The Brain

Preparation and Characterization of the Ceramsites with Microscale Pores from Iron Tailing and Fly Ash

2020 ◽  
Vol 12 ◽  
Author(s):  
Zeyang Xue ◽  
Zi Wang ◽  
Chunhu Yu ◽  
Yajing Mao ◽  
Lizhai Pei
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Time ◽  
Duration Time ◽  
Important Significance ◽  
Scanning Electron

Background: Iron tailing causes great environmental and social problems which contaminate water, air and soil. Therefore, it is of important significance to prepare iron tailing ceramsites with microscale pores which can recycle the deposited iron tailing. Objective: The aim of the research is to obtain iron tailing ceramsites with microscale pores and good mechanical performance. Methods: The iron tailing ceramsites have been characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Influence of the content of iron tailing, temperature and duration time on the mechanical performance of the obtained ceramsites was performed and the optimal sintering parameter was determined. The bulk density, apparent density and cylinder compressive strength of the obtained ceramsites increase obviously as improving the iron tailing content, temperature and sintering time. Results: Duration time and sintering temperature play important roles in the formation and size of the pores of the ceramsites. The optimal iron tailing content and sintering parameter are 70wt.%, 1100 ℃ for 40 min. The iron tailing ceramsites mainly consist of orthorhombic CaAl2Si2O8, monoclinic CaSiO3, hexagonal Ca7Si2P2O16, triclinic MgSiO3, triclinic Al2SiO5 and triclinic Ca2Fe2O5 phases. Iron tailing ceramsites from 1100 ℃ for 40 min are composed of irregular particles with several hundreds of micrometers improving the density and strength of the ceramsites. Conclusion: Iron tailing ceramsites containing microscale pores were prepared using iron tailing and fly ash, and exhibit excellent potential for the application in the field of construction.

Utilizing Iron Tailing, Sludge and Fly Ash to Prepare Ceramsites

2020 ◽  
Vol 13 (1) ◽  
pp. 16-25
Author(s):  
Zi Wang ◽  
Hongjun Chen ◽  
Chunhu Yu ◽  
Zeyang Xue ◽  
Pengxiang Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Duration Time

Background: The deposits of iron tailing will pose a great risk of environmental pollution and serious landscape impact which will affect the quality of life of humans. Therefore, it is urgent to utilize iron tailing to produce valuable products. Methods: The tailing ceramsites were analysed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The roles of the tailing content, sintering temperature and duration time in the performance of the tailing ceramsites were analysed and the optimal sintering parameters were determined. Results: The bulk density, apparent density and cylinder compressive strength of the tailing ceramsites increase considerably with the increase of the sintering temperature and duration time. The cylinder compressive strength of the tailing ceramsites increases with increasing the tailing content. The optimal sintering parameter is 1100°C for 40 min. The cylinder compressive strength of the tailing ceramsites obtained at 1100°C for 40 min reaches 10.1 MPa. XRD analysis shows that the tailing ceramsites mainly consist of CaSiO3, Al2SiO5, MgSiO3, Ca7Si2P2O16, CaAl2Si2O8, Ca2Fe2O5 and SiO2 phases when the sintering temperature and duration time were increased to 1100°C and 40 min, respectively. Conclusion: The tailing ceramsites were obtained from iron tailing, sludge and fly ash as the raw materials at 1100°C for 40 min. The obtained ceramsites exhibited high mechanical performance.

The Preparation, Structure and Electrical Conductivity of Ag-Doped La1-x-ySrxCuyMnO3-δ (0.05≤x≤0.4, y=0.1) Ceramics

2014 ◽  
Vol 1058 ◽  
pp. 185-189
Author(s):  
Yi Cao ◽  
Bao Ping Lin ◽  
Hong Yang ◽  
Ying Sun
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Diffuse Reflectance ◽  
Diffuse Reflection ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Structure Variation ◽  
X Ray ◽  
Transmission Electron ◽  
Comprehensive Study

In this paper, we have presented a comprehensive study about the preparation, structure and electrical conductivity of Ag-doped La1-x-ySrxCuyMnO3-δ(0.05≤x≤0.4, y=0.1) ceramics. We first doped Ag into La1-x-ySrxCuyMnO3-δcompounds using a sol-gel method and then the gels were sintered at 1000°C by Muffle furnace. The structure variation was systematically characterized by the X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that that silver merged well into the lattice of La1-x-ySrxCuyMnO3-δand z at.% Ag-doped La1-x-ySrxCuyMnO3-δcompounds precipitated only in one phase. As indicated by the conventional four-probe method and UV-Vis diffuse reflectance spectroscopic (DRS), the addition of Ag was dramatically effective in enhancing the electrical conductivity, whereas a slight effect of the addition of Ag on UV-Vis diffuse reflection was observed. Furthermore, the electrical conductivity increased with the enhanced sintering temperature within the temperature of 1000 °C, which proved that the dominant mechanism of the conductivity of Ag-doped ceramics was hole hopping transfer.

Direct Determination of Cadmium Speciation in MSW and Biomass Single Fly Ash Particles Using SR Based µ-XR Spectroscopy Techniques

2003 ◽  
Author(s):  
M. Caterina Camerani Pinzani ◽  
Britt-Marie Steenari ◽  
Oliver Lindqvist
Keyword(s):  
Fly Ash ◽  
Particle Surface ◽  
Chemical Properties ◽  
Direct Determination ◽  
Toxic Metal ◽  
Absorption Spectrometry ◽  
Homogeneous Distribution ◽  
High Concentration ◽  
Fluorescence Tomography ◽  
X Ray

Cadmium is a toxic metal causing environmental concern in connection with utilization and land filling of ash. Knowledge about the chemical associations of Cd in ash is fundamental in the understanding of its solubility and leachability from the ash. In the work presented here, the content, distribution and chemical forms of Cd on/in individual Municipal Solid Waste (MSW) and biomass fly ash particles have been investigated in situ by Synchrotron Radiation induced μ-X-ray fluorescence, absorption spectrometry (XAS) and fluorescence tomography. These X-ray micro-beam techniques can be used to reveal spatially resolved information about structural and chemical properties of particles. The use of an excitation energy of 27 keV made it possible to detect trace metals, such as Cd at ppm levels, but also other elements, like Ca, K, Cl and Br. Absorption spectra of Cd in the energy range around the absorption edge of Cd (26.71 keV) were recorded for micron-sized spots of ash particles. Fluorescence tomography was then use to establish if Cd compounds are situated on the particle surface (i.e. most prone to leaching) or at some depth within the particle, where they might be more shielded from chemical attack by water. The measurements indicated Cd to be preferably concentrated in some small areas (“hot-spots”) with high concentration (up to 200 ppm) in MSW fly ash particles and in a homogeneous distribution over the whole particle surface in the case of biomass. Comparisons of XAS spectra of fly ashes and reference compounds showed Cd to be present in the oxidation state +2 and mainly as CdSO4, CdO and CdCl2. Although previous studies have indicated Cd to be enriched in the smaller-size ash particles, in this study Cd was found to be reasonably well distributed throughout all the particle sizes investigated. Based on the results obtained, possible reaction mechanisms involving Cd are suggested.

Effect of Potassium Carbonate Addition on the Sintered Properties of Coal Fly Ash

2014 ◽  
Vol 602-603 ◽  
pp. 230-233 ◽  
Author(s):  
Wen Li ◽  
Bing Bing Fan ◽  
Bing Bing Wang ◽  
Bing Sun ◽  
Liang Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Potassium Carbonate ◽  
Sintering Temperature ◽  
Coal Fly Ash ◽  
Ceramic Materials ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dense Ceramic ◽  
Electronic Microscope

In this project, coal fly ash was transformed into ceramic materials by adding a certain amount of fusing agent. Ash samples were compacted and sintered with the addition of potassium carbonate (K2CO3·1/2H2O) under a suitable sintering temperature range. Mineralogy and microstructure of the obtained products were characterized by means of X-ray diffraction and field emission scanning electronic microscope techniques respectively. The results indicate that K2CO3·1/2H2O facilitates the transformation of mullite and quartz phases above 800°C, and the mineralogy phases of the product is leucite (KAlSi2O6) and potassium aluminum silicate (KAlSiO4). In the process, K+interacts with oxygen atom and destroys the original lattice. The regular morphology of the sintered samples was confirmed by the observation under SEM, which reveals a uniform dense ceramic is formed at 900°C with the 40wt% addition of K2CO3·1/2H2O.

Element distribution in the brain of rats exposed to lanthanum measured by synchrotron radiation X-ray fluorescence

2007 ◽  
Vol 272 (2) ◽  
pp. 333-337 ◽  
Author(s):  
L. X. Feng ◽  
H. Q. Xiao ◽  
X. He ◽  
Z. J. Li ◽  
F. L. Li ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Element Distribution ◽  
X Ray ◽  
The Brain
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