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Calcium oxide

About: Calcium oxide is a research topic. Over the lifetime, 7600 publications have been published within this topic receiving 66104 citations. The topic is also known as: caustic lime & quicklime.


Papers
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Journal ArticleDOI
TL;DR: In this article, the structure and the microstructure of zirconia-yttria electrolytes were investigated by optical microscopy, scanning electron microscopy and X-ray diffraction and Raman spectroscopy.
Abstract: Zirconia-based electrolytes, stabilized either with yttrium oxide or calcium oxide, were prepared in 100 to 200 μm thick layers by plasma spraying and densified by high-temperature vacuum sintering. The structure and the microstructure were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The results are compared with the data we obtained on the powders used for plasma spraying and on single crystals. In the zirconia-yttria system, dense and fully stabilized zirconia films with structural properties similar to the corresponding single crystals were obtained. On the other hand, cracks and deformations were observed on calcia-stabilized films. This phenomenon is explained by the dramatic increase of monoclinic phase content due to the preferential evaporation of calcium oxide which occurs during high-temperature vacuum sintering.

24 citations

Patent
17 Oct 2002
TL;DR: An anti-seize composition which is non-flowable and dimensionally stable at temperatures greater than about 120°F and dispensable at room temperature without the application of heat is provided in this paper.
Abstract: An anti-seize composition which is non-flowable and dimensionally stable at temperatures greater than about 120°F and dispensable at room temperature without the application of heat is provided. The composition includes a solid anti-seize lubricant, such as of metallic copper, metallic nickel, metallic aluminum, metallic lead, metallic zinc, graphite, calcium oxide, calcium carbonate, calcium fluoride, calcium stearate, lithium, molybdenum disulfide, boron nitride, barium sulfate, or combinations thereof. The anti-seize lubricant is dispersed in a carrier which is a solid at about room temperature. The carrier includes a grease with an ASTM D 217 penetration at 25°C from about 200 to about 400 mm, a matrix material, and a naphthenic petroleum oil having a viscosity of less than about 300 SUS at 100°F and having an API gravity at 60°F from about 23 to about 25. The matrix material is a polymeric material. Optionally, a refined petroleum wax may also be included.

24 citations

Journal ArticleDOI
TL;DR: In this paper, the Gibbs energies of the formation of CaO and MgO were investigated in free-evaporation experiments over the temperature range of 1830 to 2070 K. Conditions of local equilibrium were established.
Abstract: Major revisions in the enthalpies and Gibbs energies of formation of calcium oxide and magnesium oxide are presented. In free-evaporation experiments over the temperature range of 1830 to 2070 K, the kinetics of vaporization of calcium oxide and magnesium oxide have been studied. Conditions of local equilibrium were established. The results lead to new values for the standard enthalpies of formation of CaO and MgO. The ΔfH298 0 of CaO is ≈33 kJ/mol more positive than the currently tabulated value, whereas that for MgO is ≈34 kJ/mol more negative. The currently tabulated values could not account for these observations nor for other recent studies. These significant changes result in a reversal of the relative thermodynamic stabilities of CaO and MgO, with MgO now indicated as the more stable oxide at lower temperatures on Ellingham diagrams. These results are consistent with recent work on the formation of CaC2, solubility product measurements in liquid iron, and with theoretical models based on ionic radii.

24 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of superplasticizing and set retarding admixtures on cement hydration was investigated using the calorimetric method, and the shrinkage and conductivity measurements showed not only the change of kinetics of heat evolution/hydration but also the modification of the process and resulting products.

24 citations

Patent
27 Apr 1994
TL;DR: In this paper, the authors proposed a method to cut power loss in a highfrequency region by a method wherein specific amounts of silicon oxide, calcium oxide, tin oxide and/or titanium oxide, niobium oxide, zirconium oxide are contained in the material of ferrite.
Abstract: PURPOSE: To cut down power loss in a high-frequency region by a method wherein specific amounts of silicon oxide, calcium oxide, tin oxide and/or titanium oxide, niobium oxide. zirconium oxide are contained in the material of ferrite. CONSTITUTION: As for the main components, mangenese oxide, zinc oxide and iron oxide are contained and as for the sub components, silicon oxide, calcium oxide, tin oxide and/or titanium oxide, niobium oxide and zirconium oxide are contained. At this tiem, the contents of mangnese oxide in the main contents is 30-41mol% in terms of MnO, 6-16mol% of zinc oxide in terms of ZnO. On the other hand, the weight ratio of the sub components to the main components is 50-250-ppm of silicon oxide in terms of SiO 2 , 200-1500ppm of calcium oxide in terms of CaO, not exceeding 4000ppm of tin oxide in terms of SnO 2 , not exceeding 3000ppm of titanium oxide in terms of TiO 2 and the total of the tin oxide and titanium oxide exceeds 3000ppm. COPYRIGHT: (C)1995,JPO

23 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023101
2022186
2021116
2020234
2019350
2018432