scholarly journals Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Benmohamed ◽  
Rabah Alouani ◽  
Amel Jmayai ◽  
Abdesslem Ben Haj Amara ◽  
Hafsia Ben Rhaiem
Keyword(s):  
Morphological Analysis ◽  
Xrd Analysis ◽  
Mineral Elements ◽  
Cement Clinker ◽  
Free Lime ◽  
X Ray ◽  
White Cement ◽  
Portland Cement Clinker ◽  
White Portland Cement ◽  
Mineralogical Phases

The paper deals with a formation of artificial rock (clinker). Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker’s chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld). Scanning electron microscopy (SEM) was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S) and belite (C2S)), excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper.

scholarly journals Effects of Calcination Conditions on the Formation and Hydration Performance of High-Alite White Portland Cement Clinker

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 494 ◽  
Author(s):  
Lei Huang ◽  
Geling Cheng ◽  
Shaowen Huang
Keyword(s):  
Portland Cement ◽  
Mineral Composition ◽  
Sintering Temperature ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Free Lime ◽  
Sintering Time ◽  
Portland Cement Clinker ◽  
White Portland Cement

The purpose of this study was to evaluate the effects of sintering temperature and sintering time on mineral composition of high-alite white Portland cement clinker and hydration activity of the clinker. Effects of sintering temperature and sintering time on clinker mineral composition, C3S polymorph and size and hydration heat release rate were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimetry&Thermogravimetric Analysis (DSC-TG) and isothermal heat-conduction calorimetry. Results shown that, with the increase of sintering temperature (1450–1525 °C) and sintering time (60–240 min), free lime (f-CaO) in clinker decreased, C3S grain size increased, and C3S crystal type changed from T3 to M type and R type, which exhibits higher symmetry. The hydration activity of different C3S crystals ranged from high to low as follows: T3→M1→M3→R@.

Effects of CaF2 on the Formation Kinetics of Portland Cement Clinker

2011 ◽  
Vol 306-307 ◽  
pp. 966-969
Author(s):  
Chun Fang Wang ◽  
Zong Hui Zhou ◽  
Cai Xia Liu ◽  
Xin Cheng
Keyword(s):  
Portland Cement ◽  
Formation Rate ◽  
Reaction Rate Constant ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Free Lime ◽  
X Ray ◽  
Formation Kinetics ◽  
Portland Cement Clinker ◽  
Kinetics Of

Through testing the amount of the free lime and the Loss ignition, the clinker formation rate, the reaction-rate constant (K) and the activation energy (Ea) were calculated according to the Gentling equation and Arrhenius equation. The effects of CaF2on the formation kinetics of Portland cement clinker were investigated by analyzing theKandEa. X-ray diffraction (XRD) and scanning electron Microscope (SEM) were used to characterize the phase composition and the morphology of the resulting samples. The results show that the silicate minerals formation is promoted when a proper amount of CaF2is doped into the raw meal. TheKincreased from 0.7450 ×10-5s-1to 7.1588 ×10-5s-1and theEadecreased from 386 kJ/mol to 122 kJ/mol when the amount of CaF2increased from 0.0% to 2.0% in mass. However, the results were reversed at the amount of CaF2exceeding 2%.

Determination of amorphous phase levels in Portland cement clinker

2002 ◽  
Vol 17 (3) ◽  
pp. 178-185 ◽  
Author(s):  
Phe Man Suherman ◽  
Arie van Riessen ◽  
Brian O’Connor ◽  
Deyu Li ◽  
Dick Bolton ◽  
...  
Keyword(s):  
Portland Cement ◽  
Cement Clinker ◽  
Rietveld Refinements ◽  
Amorphous Component ◽  
X Ray ◽  
Absolute Phase ◽  
Portland Cement Clinker ◽  
External Phase ◽  
Long Time

The existence of glass or amorphous component in Portland cement clinker has been questioned for a long time. However, besides the crystalline phases, there are reports in the literature of noncrystalline material in cement clinker, which is considered to be the residue of the melt that has failed to crystallize. Absolute phase abundances were determined in this study by Rietveld refinements with laboratory X-ray data, using both internal and external phase composition standards. The results clearly demonstrate the existence of an amorphous component in Portland cement clinker. The presence of an amorphous component was also apparent from diffraction data for clinker from which the silicate phases had been chemically removed, using both laboratory X-ray and synchrotron radiation patterns.

Influence of Vanadium on Cement Properties and Leaching Analysis

2015 ◽  
Vol 1103 ◽  
pp. 113-119
Author(s):  
Suthatip Sinyoung ◽  
Puangrat Kajitvichyanukul
Keyword(s):  
Vanadium Oxide ◽  
Xrd Analysis ◽  
Cement Industry ◽  
Industrial Wastes ◽  
Raw Material ◽  
Renewable Energy Resources ◽  
Free Lime ◽  
X Ray ◽  
Used Oil ◽  
Us Epa

Nowadays, industrial wastes are widely used as an alternative fuel or raw material in the cement industry owing to the advantage of waste removal and gaining economic incomes from preserving non-renewable energy resources. In the present work, the effect of the addition of small amounts of vanadium in the clinkering process of cement mortar was studied. Vanadium was chosen to study as it is present in the coke commonly burned as fuel and in industrial wastes such as used oil which is used as alternative secondary fuel in cement kilns. The study simulated the burning process in a chamber furnace. Raw meal was burned with vanadium oxide (V2O5) in four concentrations from 0.01 to 1% by weight. The resulting clinker was analysed for the content of free lime and X-ray diffraction (XRD) analysis was done. These samples were also analysed by scanning electron microscope (SEM) connected with an energy-dispersive X-ray-spectrometer (EDS) to detect the composition of the clinker phase. The results show that only very high intakes of vanadium oxide higher than 0.5% by weight have measurable effects on the formation and composition of the clinker. Amounts of C3S and C2S were decreased with high intakes of vanadium. To study the leaching behavior, the microwave-assisted leach method 3051A. Result showed that vanadium was likely to be leached from cement that 15-20% of them can be leached to the environment. In case, TCLP (US EPA) test the result showed that raw material doped with vanadium up to 1 wt.%, the cement was not classified as hazardous waste.

High Aspect Ratio Hydroxyapatite Nanorods Formed by Polymer Assisted Synthesis

2014 ◽  
Vol 508 ◽  
pp. 52-55
Author(s):  
A. Joseph Nathanael ◽  
R. Yuvakkumar ◽  
Tae Hwan Oh ◽  
Sun Ig Hong
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Morphological Analysis ◽  
Polymer Concentration ◽  
Xrd Analysis ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Length Width ◽  
Size Controlled

High aspect ratio (length/width) of hydroxyapatite (HA) nanorods were prepared by polymer assisted hydrothermal synthesis. The aspect ratio of the nanorods was increased in the presence of polymer in hydrothermal method. Structural analysis was carried out by X-ray diffraction (XRD) analysis to find the purity and the crystal structure of the material. Morphological analysis was carried out by field emission scanning electron microscope (FESEM) to find the morphological variation in the presence of polymer concentration compared to pristine HA. The increased aspect ratio of the HA was visible from the morphological analysis. This shape and size controlled synthesis have an important impact in many field of research.

scholarly journals Quantitative Analysis of Portland Cement Clinker with Rietveld Refinement: Implications of the Amorphous Matter

2021 ◽  
Vol 5 (1) ◽  
pp. 75
Author(s):  
Georgios E. Christidis ◽  
Maria Dimitriadi ◽  
George Triantafyllou ◽  
Christos Tsoumeleas
Keyword(s):  
Portland Cement ◽  
Rietveld Method ◽  
Internal Standard ◽  
Complete Characterization ◽  
Cement Clinker ◽  
White Cement ◽  
Portland Cement Clinker ◽  
Amorphous Matter

Six ordinary Portland cement (OPC) clinkers and one white cement clinker were analyzed with the Rietveld method, using ZnO internal standard (IC), to determine the presence of amorphous matter (AM). All clinkers contain abundant AM and have lower silicate phase contents when compared with the same clinkers analyzed without IC, whereas the abundances of the aluminate and ferrate phases were not affected by AM. The white cement clinker had the highest AM content. Determination of AM is important for complete characterization of the OPC clinker and might contribute to a better understanding of the mechanical properties of the clinker.

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