The Ca−O (Calcium-Oxygen) system

Wriedt, H. A.

doi:10.1007/bf02880517

Cited by 24 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phase equilibrium and the thermodynamics of the (Ca + O) system have previously been discussed by Wriedt [26]. Intermediate solid phases are CaO (lime), CaO 2 (calcium peroxide), and possibly CaO 4 (=Ca(O 2 ) 2 , calcium superoxide) and CaO 6 (=Ca(O 3 ) 2 , calcium ozonide).…”

Section: (Ca + O)mentioning

confidence: 99%

Thermodynamic evaluation and optimization of the (Ca+C+O+S) system

Lindberg

Chartrand

2009

The Journal of Chemical Thermodynamics

View full text Add to dashboard Cite

Section: (Ca + O)mentioning

confidence: 99%

Thermodynamic evaluation and optimization of the (Ca+C+O+S) system

Lindberg

Chartrand

2009

The Journal of Chemical Thermodynamics

View full text Add to dashboard Cite

“…The results of the calculation of the phase diagram are shown in Figure 2 along with the reported experimental data points. Calculations yielded a eutectic at 5.5 mol% calcium oxide and 1020K and a peritectic at 19 mol% and 1110K The calcium -calcium oxide binary phase diagram has been reviewed by Wreidt (6). The calculated diagram, Figure 3, has been fitted to the experimental data of Bevan (16).…”

Section: Modeling Of Phase Diagramsmentioning

confidence: 98%

Solubility of Calcium in CaCl2-CaO

Shaw

Watson

2009

ECS Trans.

View full text Add to dashboard Cite

The solubility of calcium in calcium chloride - calcium oxide is of interest in processes reducing metal oxides in calcium chloride based salt systems. The solubility of calcium in calcium chloride was measured as 2.7mol% at 1073K. This reduced to 0.4mol% at a calcium oxide content of 9.0mol%. Experimental data for the binary components of the calcium - calcium chloride - calcium oxide ternary system has been used to construct a model of the ternary system, against which the results reported here are compared. At high calcium oxide concentrations there is reasonable agreement between model and experiment; at low calcium oxide concentrations the model predicts lower calcium concentrations than found experimentally.

show abstract

“…Due to very delicate experimental work, conflicting values ranging from 2843 K to 3223 K have been reported in the literature data. It is to be noted that both the measurements and their interpretation are challenging, as it is unsure whether CaO is melting or boiling, if the reaction is congruent or not, and even whether the compound is stoichiometric or not at such high temperatures [10]. Manara et al [19] conducted a remarkable experimental study of the melting of CaO by quasi-containerless laser heating under different atmospheres.…”

Section: Data Relative To the Melting Of Caomentioning

confidence: 99%

“…Very limited information are available regarding the CaO2 compound. The calcium peroxide is only stable at rather high oxygen pressures, as the oxygen pressures in equilibrium with both CaO and CaO2 at room temperature were reported to be about 1 bar [10]. However, there is debate in the literature concerning the stability of this compound under standard conditions.…”

Section: Thermodynamic Properties and Thermal Stability Of Cao2mentioning

confidence: 99%

“…From the review of the Ca -O system performed by Wriedt [10], the known stable compounds are solid CaO, which is stoichiometric up to at least 1400 K, and solid CaO2, which is unstable at room temperature and atmospheric pressure. The CaO4 and CaO6 compounds might be stable at high oxygen pressures and low temperatures, but their existence was not demonstrated through experiments yet.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2

Deffrennes

Jakse

Alvares

et al. 2020

Calphad

View full text Add to dashboard Cite

A complete thermodynamic description of the Ca-O system is proposed including 3 rd generation modelling of crystalline CaO, liquid and amorphous CaO, and crystalline CaO2. Compared to previous modellings, a more robust description of the thermodynamic properties of the binary phases is achieved using data recently obtained by density functional theory calculations and molecular dynamics simulations. The heat capacity of crystalline CaO is reassessed, leading to a noticeably higher value below the melting point compared to previous modellings and resulting in a slightly higher standard entropy. It is highlighted that the parameters given in terms of polynomial functions of temperature that were employed so far in 3 rd generation models to describe anharmonic contributions in the heat capacity of compounds were not suited to satisfactorily describe the thermodynamic properties of crystalline CaO. It is suggested that this observation can be generalized to most refractory oxides. Alternative terms are proposed in the Gibbs energy function that give more flexibility in fitting the experimental data and lead to more numerically reasonable values for the parameters. The liquid and amorphous CaO phase is described using the two-state model, leading to a significant improvement in the description of its heat capacity. The description of crystalline CaO2 is also improved as only estimates of the thermodynamic properties of the compound were available in previous modellings of the system. Finally, phase equilibria data on the Ca-CaO liquidus is reviewed, and it is highlighted that slight discrepancies in the relatively low temperature measurements can lead to significantly different descriptions of the liquid phase.

show abstract

The Ca−O (Calcium-Oxygen) system

Cited by 24 publications

References 26 publications

Thermodynamic evaluation and optimization of the (Ca+C+O+S) system

Thermodynamic evaluation and optimization of the (Ca+C+O+S) system

Solubility of Calcium in CaCl2-CaO

Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2

Contact Info

Product

Resources

About