Topic
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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TL;DR: In this paper, the authors show that a near surface implantation of high doses of calcium results in an oxidation of the modified layer and the formation of CaO, and by post-implantation annealing also Ca4Ti3O10 is formed.
Abstract: Pretreatment of titanium by implantation of P and Ca is of interest in order to improve the quality of hydroxyapatite coatings used to enhance its biocompatibility. A near surface implantation of high doses of calcium results in an oxidation of the modified layer and the formation of CaO. By post-implantation annealing also Ca4Ti3O10 is formed. For deeper calcium implantations, precipitation of the metastable hexagonal modification of calcium has been observed instead of the cubic equilibrium phase. By high dose implantation of phosphorus, the implanted layer becomes partly amorphized. This hinders the reaction with oxygen during implantation and room temperature aging. The thickness of the surface oxide corresponds to the native oxide layer. For high dose double implantation with both elements, due to the strong swelling effect and the incorporation of oxygen, the second implant is shifted to the surface, if the energies are chosen so that the profiles should be overlapping by implantation into pure titanium. No indication for compound formation besides calcium oxide has been found as a result of the implantation.
57 citations
TL;DR: In this paper, the total surface energies of calcium oxide and calcium hydroxide were determined by measuring the heats of solution in 2 N nitric acid of 2 O(N 2 O 2 O (n) O(n) of calcium oxides and calcium hyroxide.
Abstract: The total surface energies (or surface enthalpies) of calcium oxide and calcium hydroxide were determined by measuring the heats of solution in 2 N nitric acid of calcium oxide and calcium hydroxid...
57 citations
TL;DR: The viscosities of CaO-FeO-SiO2-CaF2 slags with various amounts of alumina addition were measured using a rotating-cylinder method in the temperature range 1714-1757 K as discussed by the authors.
Abstract: The viscosities of CaO-FeO-SiO2-CaF2 slags with various amounts of alumina addition were measured using a rotating-cylinder method in the temperature range 1714-1757 K. The first part of the experi ...
57 citations
Patent•
06 Feb 2003TL;DR: In this paper, a reaction-based process has been developed for the selective removal of carbon dioxide (CO 2 ) from a multicomponent gas mixture to provide a gaseous stream depleted in CO 2 compared to the inlet CO 2 concentration in the stream.
Abstract: A reaction-based process has been developed for the selective removal of carbon dioxide (CO 2 ) from a multicomponent gas mixture to provide a gaseous stream depleted in CO 2 compared to the inlet CO 2 concentration in the stream. The proposed process effects the separation of CO 2 from a mixture of gases (such as flue gas/fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO 2 (CaRS-CO 2 ) process consists of contacting a CO 2 laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO 2 by the formation of calcium carbonate (CaCO 3 ). Once “spent”, CaCO 3 is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO 2 . The “regenerated” CaO is then recycled for the further capture of more CO 2 . This carbonation-calcination cycle forms the basis of the CaRS-CO 2 process. This process also identifies the application of a mesoporous CaCO 3 structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.
57 citations
Patent•
28 Sep 2001
TL;DR: In this article, a method for the combined reduction of sulfur dioxide, SO 2, and nitrogen oxides, NO x, in the gas stream of a furnace from the combustion of fossil fuels is disclosed.
Abstract: A method for the combined reduction of sulfur dioxide, SO 2 , and nitrogen oxides, NO x , in the gas stream of a furnace from the combustion of fossil fuels is disclosed In a narrow gas temperature zone in a furnace, NO x is converted to nitrogen by reaction with a reducing agent such as urea or ammonia with negligible residual ammonia and other reaction pollutants In about this same temperature zone, SO 2 will react with calcium oxide particles, derived from the calcination of lime, Ca(OH) 2 , or limestone, CaCO 3 , to form CaSO 4 particles A wide size distribution of aqueous droplets, containing dispersed lime or very fine limestone particles and dissolved urea or ammonia, is injected at the outer edge of the furnace gas zone at which the SO 2 and NO x reduction reaction are effective The key element in this invention is that the aqueous droplet size distribution is optimized for the specific furnace dimension while the concentration of the reactants, urea or ammonia and lime or very fine limestone, is optimized for optimum reaction rates Special injectors produce the different size droplets that vaporize throughout said gas zone, thereby distributing said lime or limestone particles and urea or ammonia gas molecules exclusively throughout the combustion gas zone being treated Also disclosed is a system to produce said aqueous mixture and effectively accomplish this injection This method can be combined with other NO x and SO 2 reduction processes to sharply reduce overall NO x and SO 2 emissions from the combustion gas effluent
57 citations