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.

Oxides for wound healing and body repair

Abstract: The invention provides a homogeneous composition comprising a hemostatically effective amount of a charged oxide, wherein the composition has an isoelectric point, as measured in calcium chloride, below 7.3 or above 7.4. Typically, the charged oxide is selected from the group consisting of silaceous oxides, titanium oxides, aluminum oxides, calcium oxides, zinc oxides, nickel oxides and iron oxides. In some embodiments, the composition further comprises a second oxide selected from the group consisting of calcium oxide, sodium oxide, magnesium oxide, zinc oxide, phosphorus oxide and alumina. In a typical embodiment of the invention, the charged oxide is silaceous oxide, the second oxide comprises calcium oxide and the ratio, by molar ratio, of silaceous oxide to calcium oxide is 0.25 to 15. Optionally, the composition further comprises phosphorous oxide. Also described are methods of making and using such compositions.

High iron glass composition

Abstract: An improved glass composition, especially suitable for glass fiber manufacture having good fiberizing characteristics and good physical properties, and containing typically 40.0% to 65.0% silica, 4.0% to 11.0% aluminum oxide, 6.0% to 20.0% sodium oxide, 5.0% to 8.0% magnesium oxide and 6.0% to 17.0% calcium oxide, 4.0% to 12.0% ferric and ferrous oxide, and 0.0% to 7.0% potassium oxide.

Variation of Feed Chemical Composition and Its Effect on Clinker Formation-Simulation Process

Abstract: The raw materials for Portland cement production are the mixture (as fine powder in the 'Dry process') of minerals containing calcium oxide, silicon oxide, aluminum oxide, ferric oxide, and magnesium oxide. The raw materials are usually quarried from local rocks which are found in some places have already practically the desired composition and in other places require addition of the clay and limestone, as well as iron ore, or recycled materials such as CKD). The homogeneity of feed chemical composition has an important relationship to fuel consumption, kiln operation, clinker formation and cement performance. Cement quality is typically assessed by its compressive strength development in mortar and concrete. The basis for this property is a well-burned clinker with consistent chemical composition and free lime. The main reason for the clinker free lime to change in a situation with stable kiln operation is variation in the chemical composition of the kiln feed. This variation in chemical composition is related to raw mix control and the homogenization process. To ensure a constant quality of the product and maintain a stable and continuous operation of the kiln, the attention must be paid to storage and homogenization of raw materials and kiln feed. This article focuses to study the role of raw mix composition control and the homogenization process. The study have been done by computer simulation (Fortran 90) to make calculations to estimate quantities of the raw materials (limestone, clay, iron ore,.. ) required to prepare kiln feed. These calculations have been done based on knowing composition of raw materials, these field data obtained from Al-Mergheb cement plant. Due to variations in the kiln feed chemical compositions that affect its burnability and eventually the fuel consumption, so the simulation done to give a suitable composition of kiln feed to allow soft burning inside kiln. A simulation of the mixing raw materials process and estimate composition of kiln feed, as well as formed clinker were done successful through fitting of the results obtained with field data of one of the plants operating in Libya.

Study of Rice Husk Ash as Potential Source of Acid Resistance Calcium Silicate

Abstract: In present work acid resistant calcium silicate has been synthesized from silica of rice husk and calcium oxide of analytical grade. The silica from rice husk was extracted at 550oC in amorphous form and then allowed to react with calcium oxide in the presence of excess water by Sol-Gel technique to obtain calcium silicate hydrate gels. The molar ratios of Si/Ca were adjusted each time to obtain silica rich calcium silicate hydrates. The gels were dried in oven and calcined in muffle furnace at various temperatures to obtain acid resistant calcium silicate. The products were tested by analytical technique and by FTIR and XRD machines. Studies show that at higher molar ratio of Si/Ca, the heat treatment improves the acid resistivity of calcium silicate whereas at lower molar ratios the heat treatment does not make it acid resistant.

An Overview of Biodiesel Production via Calcium Oxide Based Catalysts: Current State and Perspective

Abstract: Biodiesel is a clean, renewable, liquid fuel that can be used in existing diesel engines without modification as pure or blend. Transesterification (the primary process for biodiesel generation) via heterogeneous catalysis using low-cost waste feedstocks for catalyst synthesis improves the economics of biodiesel production. Heterogeneous catalysts are preferred for the industrial generation of biodiesel due to their robustness and low costs due to the easy separation and relatively higher reusability. Calcium oxides found in abundance in nature, e.g., in seashells and eggshells, are promising candidates for the synthesis of heterogeneous catalysts. However, process improvements are required to design productive calcium oxide-based catalysts at an industrial scale. The current work presents an overview of the biodiesel production advancements using calcium oxide-based catalysts (e.g., pure, supported, and mixed with metal oxides). The review discusses different factors involved in the synthesis of calcium oxide-based catalysts, and the effect of reaction parameters on the biodiesel yield of calcium oxide-based catalysis are studied. Further, the common reactor designs used for the heterogeneous catalysis using calcium oxide-based catalysts are explained. Moreover, the catalytic activity mechanism, challenges and prospects of the application of calcium oxide-based catalysts in biodiesel generation are discussed. The study of calcium oxide-based catalyst should continue to be evaluated for the potential of their application in the commercial sector as they remain the pivotal goal of these studies.