scholarly journals SOLUBILITY OF PRECURSORS AND CARBONATION OF WATERGLASS-FREE GEOPOLYMERS

2020 ◽  
Vol 68 (5) ◽  
pp. 524-531
Author(s):  
N. Werling ◽  
F. Dehn ◽  
F. Krause ◽  
A. Steudel ◽  
R. Schuhmann ◽  
...  
Keyword(s):  
Reaction Time ◽  
Portland Cement ◽  
Amorphous Silica ◽  
Ordinary Portland Cement ◽  
Quantitative Phase Analysis ◽  
Icp Oes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Alkaline Activator

AbstractGeopolymers have the potential to function as an environmentally friendly substitute for ordinary Portland cement, with up to 80% less CO2 emission during production. The effect is best utilized for geopolymers prepared with amorphous silica instead of waterglass (Na2xSiyO2y+x) to adjust the Si:Al ratio. The reactivity of the precursors with the alkaline activator affects the final mineralogical properties of the binder. The purpose of the present study was to investigate the amount of different phases formed during geopolymerization and to understand the quantitative evolution of carbonation during geopolymer synthesis by determining the solubility of metakaolinite and amorphous SiO2 in NaOH at various concentrations. The solubility was studied by ICP-OES measurements. X-ray diffraction was used for qualitative and quantitative phase analysis of the geopolymers. The solubility of the precursors increased with calcination temperature of metakaolinite, reaction time for amorphous SiO2, and at higher NaOH concentrations. Partial dissolution resulted in free Na+, which is a source for the formation of carbonates in the geopolymers. Thermonatrite occurred prior to trona formation in all samples.

X-Ray Diffraction Intensity of Oxife Soild Soultions: Application to Qualitative and Quantitative Phase Analysis

1982 ◽  
Vol 26 ◽  
pp. 119-128 ◽  
Author(s):  
Ronald C. Gehringer ◽  
Gregory J. McCarthy ◽  
R.G. Garvey ◽  
Deane K. Smith
Keyword(s):  
Phase Analysis ◽  
Solid Solutions ◽  
Inorganic Materials ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Qualitative And Quantitative ◽  
Quantitative Analyses ◽  
End Members

Solid solutions are pervasive in minerals and in industrial inorganic materials. The analyst is often called upon to provide qualitative and quantitative X-ray phase analysis for specimens containing solid solutions when all that is available are Powder Diffraction File (PDF) data or commercial standards for the end members. In an earlier paper (1) we presented several examples of substantial errors in accuracy of quantitative analysis that can arise when the crystallinity and composition of the analyte standard do not match those of the analyte in the sample of interest. We recommended that to obtain more accurate quantitative analyses, one should determine the analyte composition (e.g., from XRF on grains seen in a SEM or from comparison of cell parameters with those of the end members) and synthesize an analyte standard with this composition and with a crystallinity approximating that of the analyte (e.g., as determined from peak breadth or α1/ α2 splitting).

Quantitative in situ X-ray diffraction analysis of early hydration of Portland cement at defined temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 112-115 ◽  
Author(s):  
C. Hesse ◽  
F. Goetz-Neunhoeffer ◽  
J. Neubauer ◽  
M. Braeu ◽  
P. Gaeberlein
Keyword(s):  
Portland Cement ◽  
Free Water ◽  
Xrd Analysis ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Early Hydration ◽  
X Ray ◽  
Main Period ◽  
Diffraction Patterns

Investigation into the early hydration of Portland cement was performed by in situ X-ray diffraction (XRD). Technical white cement was used for the XRD analysis on a D5000 diffractometer (Siemens). All diffraction patterns of the in situ measurement which were recorded up to 22 h of hydration at defined temperatures were analyzed by Rietveld refinement. The resulting phase composition was transformed with respect to free water and C-S-H leading to the total composition of the cement paste. The hydration reactions can be observed by dissolution of clinker phases as well as by the formation of the hydrate phases ettringite and portlandite. With increasing temperatures the reactions proceed faster. The formation of ettringite is directly influenced by the rate of dissolution of anhydrite and tricalcium aluminate (C3A). The beginning of the main period of hydration is marked by the start of portlandite formation. The experiments point out that a quantitative phase analysis of the cement hydration is feasible with standard laboratory diffractometers.

scholarly journals The Influence of Mayenite Employed as a Functional Component on Hydration Properties of Ordinary Portland Cement

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1958 ◽  
Author(s):  
Zhen He ◽  
Yang Li
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
Functional Component ◽  
X Ray ◽  
Consumption Rates ◽  
Hydrated Products ◽  
Experimental Findings ◽  
Good Agreement

Influence of C12A7 (12CaO·7Al2O3) as a functional component on hydration properties of Ordinary Portland Cement is studied using isothermal microcalorimetric technique, X-ray diffraction analysis, and thermodynamic calculation. Meanwhile, hydrate assemblages are simulated by hydrothermal software. C2AH8 (2CaO·Al2O3·8H2O) is generated as a transition phase during the hydration of pure C12A7, while formation of CAH10 (CaO·Al2O3·10H2O) is uncertain. Heat-releasing behavior of Ordinary Portland Cement (OPC) could be noticeably affected by C12A7, especially for the duration of interaction at boundary stage reduces with C12A7 replacement. Correspondingly, all hydration kinetic parameters first increase and then diminish with C12A7 replacement. Simulation results manifest in the main hydration products of OPC being ettringite, C-S-H (Calcium-Silicate-Hydrate) gel, portlandite and brucite. Increasing C12A7 replacement accelerates the consumption rates of gypsum and calcite that are typically included in OPC, and thus the ettringite content is changed and carbonate phases will be produced. Therefore, the microstructure properties of hydrated products of OPC are affected and the compressive strength is influenced. These predications are in good agreement with experimental findings. C12A7 can be used as a functional component to adjust the consumption rate of suphates in OPC, and also components of carbonate phases can be modified in hydrate assemblage.

On-line X-ray diffraction for quantitative phase analysis: Application in the Portland cement industry

2001 ◽  
Vol 16 (2) ◽  
pp. 71-80 ◽  
Author(s):  
Nicola V. Y. Scarlett ◽  
Ian C. Madsen ◽  
Con Manias ◽  
David Retallack
Keyword(s):  
Portland Cement ◽  
Rietveld Analysis ◽  
Cement Industry ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Joint Project ◽  
X Ray ◽  
Central Computer ◽  
Wide Range ◽  
On Line

The aim of this work was to design, construct, install, and commission an on-line, X-ray diffraction (XRD) analyzer capable of continuously monitoring phase abundances for use in process plant control. This has been achieved through a joint project between CSIRO Minerals and Fuel & Combustion Technology Pty. Ltd. with an instrument designed for use in a Portland cement manufacturing plant. Key factors in tailoring such an instrument to the cement industry were (i) the handling and presentation of a dry sample and (ii) the development of an analytical method suitable for the complex suite of phases contained within Portland cement. The instrument incorporates continuous flow of sample through the diffractometer using a purpose-built sample presentation stage. The XRD data are collected simultaneously using a wide range (120° 2θ) position sensitive detector, thus enabling rapid collection of the full diffraction pattern. The data are then analyzed using a Rietveld analysis method to obtain a quantitative estimate of each of the phases present. The instrument is controlled by a PC linked to the diffractometer through a purpose built interface. The phase abundance information is then transmitted to the central computer in the cement plant where it can be used for the control of mill parameters such as temperature and retention times as well as gypsum feed rate.

scholarly journals Qualitative and Quantitative Phase-Analysis of Undoped Titanium Dioxide and Chromium Doped Titanium Dioxide from Powder X-Ray Diffraction Data

2018 ◽  
Vol 18 (3) ◽  
pp. 486 ◽  
Author(s):  
Hari Sutrisno ◽  
Ariswan Ariswan ◽  
Dyah Purwaningsih
Keyword(s):  
Titanium Dioxide ◽  
Phase Analysis ◽  
Diffraction Data ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Crystal System ◽  
Qualitative And Quantitative ◽  
Undoped Tio2

Undoped titanium dioxide (TiO2) and a series of chromium(III) doped TiO2 (Cr-doped TiOfig. 12) with various %wt Cr atom were prepared by a reflux technique. The undoped TiO2 and Cr-doped TiO2 of 1.1, 3.9, 4.4 %wt Cr atom have been successfully analyzed both qualitative and quantitative analysis of powder X-ray diffraction (XRD) data. The qualitative analysis was carried out with the identification of phases in all samples by comparison with Crystallography Open Database (COD) and International Centre for Diffraction Data (ICDD), while the quantitative phase analysis was calculated by reference intensity ratio (RIR) and whole-pattern fitting (Rietveld analysis) methods. The undoped TiO2 consist of three phases: anatase, rutile, and brookite. In the 1.1 %wt Cr-doped TiO2 are detected presenting two phases: anatase (major) and rutile (minor). In the 3.9 %wt Cr-doped TiO2 andin the 4.4 %wt Cr-doped TiO2 consist of anatase as major phase, while CrO2 and TiO2-II phases can be detected as minor phases. The undoped TiO2 was refined in the phase, crystal system and space group of anatase (tetragonal, I41/amd), rutile (tetragonal, P42/mnm) and brookite (orthorhombic, Pbca), while the 1.1 %wt Cr-doped TiO2 was refined based on anatase (tetragonal, I41/amd), rutile (tetragonal, P42/mnm). Finally, in the 3.9 %wt Cr-doped TiO2 and 4.4 %wt Cr-doped TiO2,respectively were refined in the crystal system and space group of anatase (tetragonal, I41/amd).

A Method for Quantitative Phase Analysis of Silicon Nitride by X-Ray Diffraction

1990 ◽  
Vol 5 (3) ◽  
pp. 121-124 ◽  
Author(s):  
David J. Devlin ◽  
Kamal E. Amin
Keyword(s):  
Silicon Nitride ◽  
Iterative Method ◽  
Calibration Curve ◽  
Quantitative Measurement ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Phases ◽  
Yttrium Disilicate

AbstractThe relative intensities ratios for the determination of the relative amounts of alpha and beta phases in silicon nitride and the relative amounts of delta yttrium disilicate (Y2Si2O7) and nitrogen apatite [Y5(SiO4)3N] are reported. These constants were determined using an iterative method applicable when the pure phases are not easily prepared. In addition, a calibration curve was obtained for the quantitative measurement of free silicon in silicon nitride over the range 0 to 0.3% by weight of Si.

Conductivity Characterizationof Iron Oxide Doped 8 mol% Yttria Stabilized Zirconia

2018 ◽  
Vol 280 ◽  
pp. 58-64
Author(s):  
Tinesha Selvaraj ◽  
Johar Banjuraizah ◽  
S.F. Khor ◽  
M.N. Mohd Zainol
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Solid Electrolytes ◽  
Electrode Materials ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Solid Electrode ◽  
Short Sample ◽  
X Ray ◽  
Rietveld Quantitative Phase Analysis

A facile strategy was proposed to incorporate the dopant Fe into 8YSZ-based material, which can be potentially applied as solid electrode materials for Solid Oxide Fuel Cells (SOFC). In this study, 8YSZ powder was investigated in terms of densification, conductivity and thecrystal structure as a solid electrolytes. Therefore, varying mol% of Fe included 1, 2, and 3 were prepared for investigation. The crystalline structure of the pristine and Fe doped samples were characterized by X-ray diffraction (XRD) and the phase contents were evaluated by using the Rietveld method. Rietveld quantitative phase analysis demonstrates that the monoclinic-ZrO2phase increases (12.8 wt% to 39.7 wt%) as the concentration of Fe increases, while the amount of tetragonal-ZrO2phase drop (40.4 wt% to 11.9 wt%) dramatically. Sintering activity was applied to improve incorporation of the 8YSZ powder and the dopant Fe where the relative density increases from 77% to 92%. Sample YSZ-2Fe has been fitted with CPE equivalent circuit and achieved 6.251 x 10-6S/cm at 300 °C in air. However, it was found that conductivity levels decreased as the mol% of Fe increased. In short, sample YSZ-2Fe ceramic demonstrated good results in terms of densification (92.09%), cubic ZrO2phase (22 wt%) and conductivity 6.251 x 10-6S/cm.

Quantitative Phase Analysis By Linear Regression of Chemistry on X-Ray Diffraction Intensity

1987 ◽  
Vol 2 (2) ◽  
pp. 96-98 ◽  
Author(s):  
Jacques Renault
Keyword(s):  
Linear Regression ◽  
Quantitative Information ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
Mineralogical Analysis ◽  
X Ray ◽  
Reduction Program ◽  
Speed Of Analysis ◽  
Artificial Mixtures

AbstractXRF and XRD measurements made on a single pressed powder briquet can be combined to give more quantitative information than either technique employed alone. Speed of analysis and simplification of sample preparation are also enhanced. The algorithm presented here uses multiple linear regression of the concentrations of one or more elements on the corrected X-ray diffraction intensities of the phases containing them. The data reduction program runs on a microcomputer. Data are presented to show its application to mineralogical analysis of artificial mixtures of quartz, microcline (a feldspar) and calcite.

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