Accuracy in Rietveld quantitative phase analysis of Portland cements

2003 ◽  
Vol 36 (5) ◽  
pp. 1169-1176 ◽  
Author(s):  
A. G. De la Torre ◽  
M. A. G. Aranda
Keyword(s):  
Rietveld Method ◽  
High Energy ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Quantitative Phase Analysis ◽  
Portland Cements ◽  
X Ray ◽  
Relative Errors ◽  
Rietveld Quantitative Phase Analysis

The polymorphs that constitute most Portland cements have been synthesized: tricalcium silicate, dicalcium silicate, aluminate, ferrite, gypsum, bassanite and calcite. They have been used to prepare artificial mixtures,i.e.white Portland clinker, grey Portland clinker and two types of grey Portland cements. Quantitative mineralogical analyses of these mixtures have been obtained by laboratory X-ray powder diffraction (λ = 1.54 Å) and the Rietveld method. To assess the accuracy of these analyses, high-energy synchrotron X-ray powder data (λ = 0.40 Å) for the same mixtures have also been studied. Furthermore, synchrotron X-ray powder data were collected for binary mixtures of the polymorphs and a corundum standard. This was done to determine the presence of impurity crystalline phases in the synthesized samples and to check the presence of non-negligible amorphous phase contents. The errors in the synchrotron X-ray analyses are quite low (usually smaller than 1 wt%). The relative errors in the laboratory X-ray analyses are of the order of 2% for the main phases and increase to approximately 5–10% for the low-content components. These errors are acceptable in the factory environment and the routine application of this methodology in the cement industry is being implemented.

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.

scholarly journals Structural Properties Analysis of Mg-β-TCP by X-ray Powder Diffraction with the Rietveld Refinement

2020 ◽  
Vol 9 (4) ◽  
pp. 1562-1568
Keyword(s):  
Powder Diffraction ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
Structural Refinement ◽  
Osteoporosis Therapy ◽  
X Ray ◽  
Cell Parameters ◽  
Biomineralization Process ◽  
Resultant Powder ◽  
Rapid Reaction

The incorporation of magnesium in the synthetic apatite has been associated with the biomineralization process and osteoporosis therapy in humans and animals. β-tricalcium phosphate (β-TCP) is one of the most common bioceramics widely applied in bone cement and implants. In this work, Ca-deficient apatite (CDA) with a theoretical 0.08 Mg/(Ca+Mg) ratio was synthesized by the rapid reaction between Ca(OH)2, MgCl2.6H2O and H3PO4 at 40°C and the resultant powder calcined at 650 °C for 10h. X-ray powder diffraction analysis (XRD), in combination with the Rietveld method (Fullprof-suite), was employed for quantitative phase analysis and structural refinement. The results of XRD indicate that magnesium can substitute for calcium into a β-TCP structure inducing a reduction of the cell parameters and the compound crystallizes in the rhombohedral R3c structure, with the following unit cell constants: a = b = 10.3560 Å, c = 37.1718 Å, and cell volume V = 3452.44. The analysis indicated that the substitution of Mg2+ on the M(4) and M(5) sites were, approximately, 2.61 and 6.97 mol%, corresponding to the Ca2.72(MgIV0.07, MgV0.21)(PO4)2 stoichiometric formula and 0.09 Mg/(Ca+Mg) ratio.

scholarly journals X-ray diffraction analysis of MTA-Plus, MTA-Angelus and DiaRoot BioAggregate

2014 ◽  
Vol 08 (02) ◽  
pp. 211-215 ◽  
Author(s):  
Yeliz Guven ◽  
Elif Bahar Tuna ◽  
Muzaffer Emin Dincol ◽  
Oya Aktoren
Keyword(s):  
Crystal Structure ◽  
Tantalum Oxide ◽  
Xrd Analysis ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Glass Slide ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tricalcium Aluminate

ABSTRACT Objective: The purpose of this study was to investigate and compare the crystalline structures of recently released MTA Plus (MTA-P), MTA Angelus (MTA-A), DiaRoot BioAggregate (BA) by X-ray diffraction (XRD) analysis. Materials and Methods: Phase analysis was carried out on powder and set forms of tested materials. The powder specimens placed into sample holders that were packed with a glass slide and the set samples prepared according to the manufacturer's instructions were placed into molds. The samples after being set for three days at 37°C and 100% humidity in an incubator were mounted onto the XRD machine and phase identification was accomplished using a search-match software program. Results: XRD findings indicated that major constituents of MTA-P were bismuth oxide, portlandite, dicalcium silicate and tricalcium silicate. The crystal structure of MTA-A were similar to those of MTA-P except for the absence of portlandite. Additionally, MTA-A had tricalcium aluminate differing from MTA-P. BA mainly differed from MTA-P and MTA-A by the radiopacifier (tantalum oxide-TO) in its composition. Conclusions: The majority of constituents of the tested materials have shown similarity except for the presence of tricalcium aluminate in MTA-A and the inclusion of TO in BA. In addition, set MTA-P showed a strong peak of portlandite.

Mineral Waste Coupled with Boron Oxide for Producing Active Belite Cement Clinker

2013 ◽  
Vol 405-408 ◽  
pp. 2564-2575
Author(s):  
Yan Jun Liu ◽  
Yong Chao Zheng
Keyword(s):  
High Temperature ◽  
Boron Oxide ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Cement Clinker ◽  
Strength Development ◽  
Complete Replacement ◽  
Belite Cement ◽  
Mineral Waste

This paper presents a laboratory study on active belite cement clinker using boron oxide as dopant to stabilize high temperature phases of Dicalcium silicate (C2S), and mineral waste as siliceous materials in complete replacement of clay. The clinker samples were soaked in Muffle Furnace at different burning temperatures and for various time durations, and then, cooled down to room temperature using air blower. Quantitative X-ray Diffraction analysis (QXRD) by Rietveld method indicates that major mineral components are Dicalcium Silicate (C2S), Ferrite (C2 (A0.48F1.52) O5) and trace amount of Tricalcium Silicate (C3S) in the cement clinkers. Among them, Dicalcium silicate is over 85 percent, Ferrite around 10 percent and Tricalcium silicate less than 10 percent. Thermogravimetric and Differential Scanning Calorimetric (TGA-DSC) spectrum shows that there is no significant phase change while cement clinker was cooling down, which means significant amount of high temperature polymorphic C2S was stabilized during cooling process. It is agreeable with the results from QXRD analysis. Specifically, among polymorphic belite phases, αH-C2S accounts for around 66% of cement clinker, and αL-C2S for about 22% of cement clinker. In addition, massive belite phase was identified by Scanning Electronic Microscope (SEM) analysis and Light Microscopy analysis. At last, the mechanical tests on active belite cement show that active belite cement clinker has a slow strength development at early ages, but rapid strength gain at 28 days in comparison with belite clinker without adding boron oxide. Thus, this active belite cement clinker demonstrates very promising prospect in sustainable cement industry development. Keywords: Active Belite Cement Clinker; Doped; Boron Oxide; αH-C2S; αL-C2S; Strength Development

Active Belite Cement Clinker Produced with Mineral Waste

2012 ◽  
Vol 610-613 ◽  
pp. 2378-2385 ◽  
Author(s):  
Yan Jun Liu ◽  
Yong Chao Zheng
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Mechanical Tests ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Cement Clinker ◽  
Strength Development ◽  
Belite Cement ◽  
Mineral Waste

This paper presents a laboratory study on active belite cement linker using mineral waste as one of the major raw meal components. The main chemical component of mineral waste employed in this study is silica (SiO2), around 70%. The raw meals were soaked in Muffle Furnace at 1350oC for 10 minutes and 20minutes respectively, then, cooled down to room temperature using air blower. Boron Oxide was used to stabilize high temperature phases of C2S. QXRD analysis indicates that active belite cement clinker has major mineral components consisting of Dicalcium Silicate (C2S), Ferrite (C2 (A0.48F1.52) O5) and trace amount of Tricalcium Silicate (C3S). Among them, Dicalcium silicate is over 85 percent, Ferrite around 10 percent and Tricalcium silicate less than 10 percent. Also, significant amount of high temperature polymorphic C2S was stabilized under room temperature. Among polymorphic belite phases, αH-C2S accounts for around 66% of cement clinker, and αL-C2S for about 22% of cement clinker. Scanning Eαlectronic Microscope (SEM) analysis also shows coαnsiderable round grains of C2S. TGA-DSC spectrum indicated there is no significant phase change while cement clinker was cooling down. Also, the mechanical tests on active belite cement show that active belite cement clinker has a slow strength development at early ages, but rapid strength gain over 70Mpa at 28 days. Thus, this active belite cement clinker demonstrates very promising prospect in sustainable cement industry development.

scholarly journals Quantitative Phase Analysis of Skarn Rocks by the Rietveld Method Using X-ray Powder Diffraction Data

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 894
Author(s):  
Yana Tzvetanova ◽  
Ognyan Petrov ◽  
Thomas Kerestedjian ◽  
Mihail Tarassov
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
Quantitative Phase Analysis ◽  
Chemical Compositions ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Fine Grained ◽  
Variable Chemical

The Rietveld method using X-ray powder diffraction data was applied to selected skarn samples for quantitative determination of the present minerals. The specimens include garnet, clinopyroxene–garnet, plagioclase–clinopyroxene–wollastonite–garnet, plagioclase–clinopyroxene–wollastonite, plagioclase–clinopyroxene–wollastonite–epidote, and plagioclase–clinopyroxene skarns. The rocks are coarse- to fine-grained and characterized by an uneven distribution of the constituent minerals. The traditional methods for quantitative analysis (point-counting and norm calculations) are not applicable for such inhomogeneous samples containing minerals with highly variable chemical compositions. Up to eight individual mineral phases have been measured in each sample. To obtain the mineral quantities in the skarn rocks preliminary optical microscopy and chemical investigation by electron probe microanalysis (EPMA) were performed for the identification of some starting components for the Rietveld analysis and to make comparison with the Rietveld X-ray powder diffraction results. All of the refinements are acceptable, as can be judged by the standard indices of agreement and by the visual fits of the observed and calculated diffraction profiles. A good correlation between the refined mineral compositions and the data of the EPMA measurements was achieved.

Rietveld Quantitative Phase Analysis of Non-Stoichiometric Cordierite Synthesised from Mainly Talc and Kaolin: Effect of Sintering Temperature

2010 ◽  
Vol 173 ◽  
pp. 190-195
Author(s):  
Johar Banjuraizah ◽  
Mohamad Hasmaliza ◽  
Zainal Arifin Ahmad
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
Secondary Phases ◽  
Grinding Media ◽  
Heat Treated ◽  
Higher Temperature ◽  
New Phase ◽  
Rietveld Quantitative Phase Analysis

Indialite or α-cordierite was synthesized by glass crystallization method using mainly talc and kaolin and with small amount of MgO, Al2O3, SiO2 to compensate the chemical formulation of non-stoihiometric compositions of cordierite. (3MgO.1.5Al2O3.5SiO2). B2O3, P2O5 and CaO was also added to decrease the melting and sintering temperature of cordierite. The glasses were pelletized and sintered from 850oC up to 1050oC. Phase compositions of both heat treated glass was quantified by X-ray powder diffraction data by the Rietveld method using TOPAS Ver 3 software. Result shows that about 60wt% of α cordierite has successfully crystallized at 850oC. Beside secondary phases (forsterite) which come from initial raw materials, phases from grinding media were also presents in the sample. The contamination was considered high since it has reacted with existence phases to form a new phase at higher temperature. Without any contamination from grinding it was expected to obtain more than 90wt% α cordierite using the same composition.

Structure and microstructure of gypsum and its relevance to Rietveld quantitative phase analyses

2004 ◽  
Vol 19 (3) ◽  
pp. 240-246 ◽  
Author(s):  
Ángeles G. De la Torre ◽  
María-Gema López-Olmo ◽  
Carmen Álvarez-Rua ◽  
Santiago García-Granda ◽  
Miguel. A. G. Aranda
Keyword(s):  
Quantitative Phase Analysis ◽  
Structural Description ◽  
Two Dimensional ◽  
Standard Mixture ◽  
X Ray ◽  
Quantitative Phase ◽  
Synchrotron Powder Diffraction ◽  
Peak Broadening ◽  
Structure And Microstructure ◽  
Rietveld Quantitative Phase Analysis

Single crystals of gypsum were studied in a diffractometer equipped with a CCD two-dimensional detector. The microstructure of the crystal gave wide poorly shaped spots showing sometimes curved streaks around the spots, which made the integration process very difficult, yielding a low quality structure. The crystal structure and microstructure of gypsum has been studied by high-resolution synchrotron powder diffraction of a ground single crystal. The intensities in the synchrotron powder pattern can be reliably fitted although the peak shape displays anisotropic peak broadening. The Rietveld results for gypsum were a=6.522 91(3) Å, b=15.197 63(9) Å, c=6.522 91(3) Å, β=118.479(1)°, V=494.536(5) Å3 and Z=4 (s.g. I2/c) with RWP=5.39% and RF=1.64%. We have also studied the influence of the structural description used for gypsum in a synchrotron Rietveld quantitative phase analysis of a standard mixture containing 50 wt % of CaSO4⋅2H2O and Al2O3. Finally, the effects of the type of preferred orientation correction for laboratory X-ray powder data are also discussed. © 2004 International Centre for Diffraction Data.

In situsynchrotron powder diffraction study of active belite clinkers

2007 ◽  
Vol 40 (6) ◽  
pp. 999-1007 ◽  
Author(s):  
Ángeles G. De la Torre ◽  
Khadija Morsli ◽  
Mohammed Zahir ◽  
Miguel A.G. Aranda
Keyword(s):  
High Temperature ◽  
High Resolution ◽  
Powder Diffraction ◽  
Polymorphic Transformation ◽  
High Energy ◽  
Dicalcium Silicate ◽  
Polymorphic Transformations ◽  
X Ray ◽  
High Temperature Reactions

The clinkerization processes to form belite clinkers, with theoretical compositions close to 60 wt% of Ca2SiO4, have been studiedin situby high-resolution high-energy (λ = 0.30 Å) synchrotron X-ray powder diffraction. In order to obtain active belite cements, different amounts of K2O, Na2O and SO3have been added. The existence range of the high-temperature phases has been established and, furthermore, Rietveld quantitative phase analyses at high temperature have been performed for all patterns. The following high-temperature reactions have been investigated: (i) polymorphic transformations of dicalcium silicate, \alpha_{\rm L}'-Ca2SiO4↔ \alpha_{\rm H}'-Ca2SiO4from 1170 to 1230 K, and \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4from 1500 to 1600 K; (ii) melting of the aluminates phases, Ca3Al2O6and Ca4(Al2Fe2)O10, above ∼1570 K; and (iii) reaction of Ca2SiO4with CaO to yield Ca3SiO5above ∼1550 K. Moreover, in all the studied compositions the temperature of the polymorphic transformation \alpha_{\rm H}'-Ca2SiO4↔ α-Ca2SiO4has decreased with the addition of activators. Finally, active belite clinkers were produced as the final samples contained α-belite phases.

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