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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.


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Journal ArticleDOI
TL;DR: The results show that the steel slag asphalt permeable mixture had good permeability, water stability, and Marshall stability, as well as good high-temperature stability and a low expansion rate.
Abstract: Steel slag is an industrial solid waste with the largest output in the world. It has the characteristics of wear resistance, good particle shape, large porosity, etc. At the same time, it has good adhesion characteristics with asphalt. If steel slag is used in asphalt pavement, it not only solves the problem of insufficient quality aggregates in asphalt concrete, but can also give full play to the high hardness and high wear resistance of steel slag to improve the performance of asphalt pavement. In this study, a steel slag aggregate was mixed with road petroleum asphalt to prepare a permeable steel slag–asphalt mixture, which was then compared with the permeable limestone–asphalt mixture. According to the Technical Regulations for Permeable Asphalt Pavement (CJJT 190-2012), the permeability, water stability, and Marshall stability of the prepared asphalt mixtures were tested and analyzed. In addition, the high-temperature stability and expansibility were analyzed according to the Experimental Regulations for Highway Engineering Asphalt and Asphalt Mixture (JTG E20-2011). The chemical composition of the steel slag was tested and analyzed by X-ray fluorescence spectrometer (XRF). The mineral composition of the steel slag was tested and analyzed by X-ray diffractometer (XRD). The asphalt was analyzed by Fourier transform infrared spectroscopy (FTIR). The results show that the steel slag asphalt permeable mixture had good permeability, water stability, and Marshall stability, as well as good high-temperature stability and a low expansion rate. The main mineral composition was ferroferric oxide, the RO phase (RO phase is a broad solid solution formed by melting FeO, MgO, and other divalent metal oxides such as MnO), dicalcium silicate, and tricalcium silicate. In the main chemical composition of steel slag, there was no chemical reaction between aluminum oxide, calcium oxide, silicon dioxide, and asphalt, while ferric oxide chemically reacted with asphalt and formed new organosilicon compounds. The main mineral composition of the steel slag (i.e., triiron tetroxide, dicalcium silicate, and tricalcium silicate) reacted chemically with the asphalt and produced new substances. There was no chemical reaction between the RO phase and asphalt.

29 citations

Journal ArticleDOI
TL;DR: In this paper, a model describing the chemical kinetics of the sulphation of calcium oxide has been developed in terms of elementary chemical reaction mechanisms, which predicts that the rate-determining reaction at low tempeatures is the disproportionation of calcite and/or the reaction between calcium oxide and sulphur trioxide.

29 citations

Journal ArticleDOI
TL;DR: In this paper, fine powders consisting of 0.1-0.5 µm size crystallites of CaTiO3 are prepared at 150-200°C by the hydrothermal method starting from hydrated titania gel and reactive calcium oxide suspended as an aqueous slurry in an autoclave.

29 citations

Journal ArticleDOI
TL;DR: In this paper, the feasibility of calcium oxide for hydroxyapatite preparation was evaluated by the chemical precipitation with phosphoric acid, and X-ray diffraction confirmed that single phase of hydrophylla was obtained.
Abstract: Calcium oxide was successfully derived from eggshell waste. It was employed as a calcium precursor in order to prepare hydroxyapatite. It can be noted that eggshell presented high thermal stability, and it was calcined from 700 to 1000 °C for 3 h for calcium oxide formation. Morphological properties were investigated, and it presented the irregular shape with a variation on size. The feasibility of calcium oxide for hydroxyapatite preparation was evaluated by the chemical precipitation with phosphoric acid. X-ray diffraction confirmed that single phase of hydroxyapatite was obtained.

29 citations

Patent
03 Nov 1992
TL;DR: In this paper, a process for pathogen reduction in waste where dewatered sludge having a solids content in the range of 10-60% is mixed with an additive selected from the group consisting of calcium oxide or calcium carbonate group.
Abstract: A process for pathogen reduction in waste where dewatered sludge having a solids content in the range of 10-60% is mixed with an additive selected from the group consisting of calcium oxide or calcium carbonate group. Hydration to calcium hydroxide occurs with an attendant release of heat. The pH of the sludge is then elevated and the heat of the hydration reaction is retained resulting in effective neutralization of pathogens.

29 citations


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