Calcium oxide

Production and Properties: Calcium oxide is produced by thermal decomposition of materials containing calcium carbonate through a process called calcination or limeburning, liberating carbon dioxide. The annual worldwide production of calcium oxide is around 283 million tonnes. Quicklime, a form of calcium oxide, has a high affinity for water and is a desiccant. Calcium oxide is a distinct mineral species with the unit formula CaO, known as Lime, with unique properties and crystal structure. Industrial and Mining Applications: Calcium oxide is a key ingredient in various industrial processes, including cement production, basic oxygen steelmaking, and aerated concrete production. It is used in mining for rock breaking, in the petroleum industry for water detection, in paper production for chemical recovery, and in plaster production for flooring and construction. The chemical is utilized in carbon capture and storage processes and in fluegas desulfurization in chemical or power production. Historical and Military Uses: Historically, calcium oxide has been used to enhance the durability of ancient Roman concrete and accelerate the decomposition of corpses. In warfare, it has been used as a weapon by Roman generals and potentially in medieval naval warfare, including in limemortars to attack enemy ships. English Navy reportedly used quicklime to blind an invading French fleet, and it may have been a component of Greek fire. Substitutes and Alternatives: Limestone, calcined gypsum, cement, fly ash, and magnesium hydroxide are potential substitutes for calcium oxide in various applications like agriculture, construction, and pH control. Magnesium oxide can replace dolomitic lime as a flux in steelmaking. Limestone, despite being slower to react, is considerably cheaper than calcium oxide. Safety and Hazards: Quicklime can cause severe irritation when inhaled or in contact with moist skin or eyes, leading to coughing, burns, nausea, and vomiting. Safety precautions are necessary due to the vigorous reaction of quicklime with water, which can release enough heat to ignite combustible materials. While quicklime is not considered a fire hazard, proper handling is crucial to avoid accidents.