Applications of the Rietveld method to quantify the crystalline phases of Portland cement clinker doped with nickel and chromium

2008 ◽  
Vol 23 (S1) ◽  
pp. S42-S45 ◽  
Author(s):  
Andréa Vidal Ferreira ◽  
Ariete Righi ◽  
Fernando Gabriel Silva Araújo ◽  
Denise Crocce Romano Espinosa ◽  
Jorge Alberto Soares Tenório
Keyword(s):  
Portland Cement ◽  
Nickel Oxide ◽  
Hazardous Waste ◽  
Powder Diffraction ◽  
Industrial Waste ◽  
Pattern Analysis ◽  
Rietveld Method ◽  
Cement Clinker ◽  
X Ray ◽  
Portland Cement Clinker

The effects of chromium or nickel oxide additions on the composition of Portland clinker were investigated by X-ray powder diffraction associated with pattern analysis by the Rietveld method. The co-processing of industrial waste in Portland cement plants is an alternative solution to the problem of final disposal of hazardous waste. Industrial waste containing chromium or nickel is hazardous and is difficult to dispose of. It was observed that in concentrations up to 1% in mass, the chromium or nickel oxide additions do not cause significant alterations in Portland clinker composition.

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.

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