Influence of CaF2 on the Formation Kinetics of Belite-Calcium Barium Sulphoaluminate Cement Clinker

2014 ◽  
Vol 541-542 ◽  
pp. 118-122
Author(s):  
Yong Bo Huang ◽  
Shou De Wang ◽  
Yan Ting Zhao ◽  
Chen Chen Gong ◽  
Ling Chao Lu
Keyword(s):  
Activation Energy ◽  
Energy Consumption ◽  
Diffusion Mechanism ◽  
Cement Clinker ◽  
Preparation Process ◽  
Sulphoaluminate Cement ◽  
Formation Kinetics ◽  
Formation Dynamics ◽  
Kinetics Of ◽  
Experimental Preparation

This paper studies the formation dynamics of belite-calcium barium sulphoaluminate cement clinker with and without CaF2. The results suggest that, under the condition of the experimental preparation process, the formation process of belite-calcium barium sulphoaluminate cement clinker is controlled by diffusion mechanism in the temperature range of 1250-1380¡æ and the formation dynamics fits nicely with D4̍́˽̂ځ˿̃˽˸́˽ځ˹2/3=kt. Apparent activation energy was calculated to be 250 kJ·mol-1and 195 kJ·mol-1 for sample clinker without and with 0.6% CaF2 content. It is concluded that CaF2 contributes a lot to the reduction in energy consumption during the process of sintering belite-calcium barium sulphoaluminate cement clinker.

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%.

Kinetics and Mechanism of the Microwave Synthesis of Barium Titanate

1996 ◽  
Vol 430 ◽  
Author(s):  
Hanlin Zhang ◽  
Shixi Ouyang ◽  
Hanxing Liu ◽  
Yongwei Li
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Microwave Field ◽  
Formation Rate ◽  
Xrd Analysis ◽  
Conventional Heating ◽  
Heating Process ◽  
Formation Kinetics ◽  
Kinetics Of ◽  
Synthesis Of Barium Titanate

AbstractThe formation kinetics of BaTiO3from the solid-state BaCO3and TiO2powder in a microwave field was investigated. The quantitative XRD analysis and the model considered the volume change between reactant and product were used in this experiment. Results show that the formation rate of BaTiO3in a microwave field is much faster than upon conventional heating. The activation energy of the solid state reaction for BaTiO3was measured as 58 kJ/mol. This indicates the enhancement of diffusion by the microwave heating process.

Enhancement of Aurivillius Phase Formation Kinetics in SBT Thin Films using Nanoparticle Seeding

2003 ◽  
Vol 784 ◽  
Author(s):  
Yun-Mo Sung ◽  
Woo-Chul Kwak ◽  
Se-Yon Jung ◽  
Seung-Joon Hwang
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Phase Transformation ◽  
Phase Formation ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
X Ray ◽  
Si Substrates ◽  
Formation Kinetics ◽  
Kinetics Of

ABSTRACTPt/Ti/SiO2/Si substrates seeded by SBT nanoparticles (∼60–80 nm) were used to enhance the phase formation kinetics of Sr0.7Bi2.4Ta2O9 (SBT) thin films. The volume fractions of Aurivillius phase formation obtained through quantitative x-ray diffraction (Q-XRD) analyses showed highly enhanced kinetics in seeded SBT thin films. The Avrami exponents were determined as ∼1.4 and ∼0.9 for unseeded and seeded SBT films, respectively, which reveals different nucleation modes. By using Arrhenius–type plots the activation energy values for the phase transformation of unseeded and seeded SBT thin films were determined to be ∼264 and ∼168 kJ/mol, respectively. This gives a key reason to the enhanced kinetics in seeded films. Microstructural analyses on unseeded SBT thin films showed formation of randomly oriented needle-like crystals, while those on seeded ones showed formation of domains comprised of directionally grown worm-like crystals.

scholarly journals Isothermal kinetics of titanium-oxo-alkoxy clusters formation

2011 ◽  
Vol 43 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Z.Z. Baros ◽  
B.K. Adnadjevic ◽  
V.B. Pavlovic
Keyword(s):  
Activation Energy ◽  
Power Law ◽  
Isothermal Kinetics ◽  
Molar Ratio ◽  
Titanium Tetraisopropoxide ◽  
Formation Reaction ◽  
Formation Kinetics ◽  
Power Law Function ◽  
Absorbance Changes ◽  
Kinetics Of

In this article, the influences of titanium tetraisopropoxide Ti(OR)4 (R = Pri) concentration, molar ratio, h = [H2O]/[Ti(OR)4], and temperature, on the formation kinetics of the titanium-oxo-alkoxy clusters (TOAC), were studied. The TOAC formation isothermal kinetics was monitored by measuring absorbance changes versus time in the reaction mixture at predefined wavelength ? = 350 nm. It was determined that the isothermal rate of clusters formation is a power law function of titanium tetraisopropoxide concentration and the molar concentration of water (cw). The kinetic parameters ? and ? were calculated. The apparent activation energy Ea values in the clusters formation reaction has been calculated and correlated with the change of titanium tetraisopropoxide concentration and molar ratio. The model for mechanism of TOAC formation is proposed.

Effect of Doped with BaO on the Formation Dynamics of Alite in Alite-Rich Cement Clinker

2011 ◽  
Vol 306-307 ◽  
pp. 998-1002 ◽  
Author(s):  
Shou De Wang ◽  
Xiang Yang Guo ◽  
Ling Chao Lu ◽  
Xin Cheng
Keyword(s):  
Activation Energy ◽  
Liquid Phase ◽  
Diffusion Equation ◽  
Apparent Activation Energy ◽  
Three Dimensional ◽  
Spherical Model ◽  
Experimental Results ◽  
Cement Clinker ◽  
Formation Kinetic ◽  
Formation Dynamics

Effect of doped BaO on the formation dynamics of alite of alite-rich cement clinker was investigated. The experimental results indicated that its formation kinetic satisfied with three- dimensional spherical model and accorded with Glinstling diffusion equation. Doped BaO could decrease dramatically the apparent activation energy of alite-rich cement clinker. This was contributed to the combination of C2S and CaO in liquid phase, and acceleration of formation of alite-rich cement clinker.

Kinetics of Desulfuration Product Sulphoaluminate Calcium

2010 ◽  
Vol 113-116 ◽  
pp. 1814-1817 ◽  
Author(s):  
Hui Ling Guo ◽  
Jun Lin Xie
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Formation Rate ◽  
Experimental Investigations ◽  
Exponential Factor ◽  
First Order ◽  
First Order Kinetics ◽  
Formation Kinetics ◽  
Competitive Reactions ◽  
Kinetics Of

The formation kinetics of sulphoaluminate calcium was studied by variations of sulfur release with time from SC-132 based on competitive reactions, the generation of sulphoaluminate calcium and the decomposition of CaSO4. Experimental investigations and theoretical derivations show that the formation rate of sulphoaluminate calcium can be described as first-order kinetics at high temperature, and it belongs to the mechanism of random nucleus growth. The apparent activation energy is 456.37 KJ•mol-1 and pre-exponential factor is 1.545×1012.

Formation Kinetics of Regenerated Cement Clinker Calcined by Using Wasted Recycling Concrete Powders as Raw Meals

2014 ◽  
Vol 1073-1076 ◽  
pp. 1309-1312 ◽  
Author(s):  
Jie Zhang ◽  
Zong Hui Zhou ◽  
Xin Cheng
Keyword(s):  
Reaction Rate ◽  
Sintering Temperature ◽  
High Strength ◽  
Reaction Rate Constant ◽  
Cement Clinker ◽  
Formation Kinetics ◽  
Portland Cement Clinker ◽  
Microstructure Morphology ◽  
Cement Clinkers ◽  
Kinetics Of

Artificial aggregates with high strength and a similar mineral composition to Portland cement clinker are made up of industrial waste and limestone, which are prepared for recycling concrete. Regenerated cement clinker is fabricated by recycling concrete powder added with a small amount of correction raw materia. Through the Gentling equation computing and microstructure morphology observation, the apparent activation energy (Ea) of two kinds of regenerated cement clinkers are 199 kJ/mol and 333 kJ /mol respectively, which is lower than that of traditional cement clinker (518 kJ/mol). The reaction rate constant (k) of regenerated cement clinker are about 4.8108×10-5 s-1 and 2.5003×10-5 s-1 at 1350°C. At the process of calcination, the formation temperature of C3S and sintering temperature of regenerated cement clinker are lower than that of the traditional cement clinker.

Kinetics of the Solid State Reaction between MoO3 and SrCO3

1972 ◽  
Vol 27 (6) ◽  
pp. 1020-1022 ◽  
Author(s):  
G. Flor ◽  
V. Massarotti ◽  
R. Riccardi
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Apparent Activation Energy ◽  
Solid State Reaction ◽  
Diffusion Mechanism ◽  
Optical Observations ◽  
Kcal Mole ◽  
Temperature Range ◽  
Kinetics Of

AbstractThe solid state reaction MoO3 + SrCO3 → SrMoO4+ CO2 has been studied on mixtures of powdered reagents. Thermogravimetric measurements in the temperature range 412° -498 °C have been made on different mixtures and under different atmospheres. Moreover, optical observations and conductometric measurements have been carried out. The results show that the reaction is governed by a diffusion mechanism with an apparent activation energy of (60 ± 1) kcal/mole and that the main diffusing species is the Mo6+ ion.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

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