Calciumoxide

Uses1. Calcium oxide can be used in the manufacture of calcium carbide, soda ash, bleaching powder, used as building materials, refractoriness’, desiccant and soil conditioner and calcium fertilizer 2. It can be used as an analysis reagent and flux agent for manufacturing fluorescence powder. 3. It can be used in the manufacture of calcium carbide, soda ash, bleaching powder, also used for leather, waste water purification 4. Calcium oxide can be used as building materials, metallurgical flux agent and the major raw materials for the manufacturing of calcium hydroxide and a variety of calcium compounds. It is also the inexpensive alkali in the chemical industry. It is widely used in pesticides, paper, food, petrochemical, leather, waste water purification and so on. It can also be used for the drying of the laboratory ammonia and alcohol dehydration. 5. Use as drug carriers. 6. Uses as analysis reagents; Calcium oxide can be applied to steel, pesticides, pharmaceuticals, non-ferrous metals, fertilizers, leather and manufacturing of calcium hydroxide, drying of laboratory ammonia, carbon dioxide absorbent and alcohol dehydration.

DescriptionCalcium oxide (CaO, CAS Reg. No. 1305-78-8) is also known as lime, quick lime, burnt lime, or calx. Lime does not occur naturally since it reacts so readily with water (to form hydrated lime) and carbon dioxide (to form limestone). It is produced from calcium carbonate, limestone, or oyster shells by calcination at temperatures of 1,700-2,450℃. Calcium Oxide is a solid with a very high affinity for water - it will react with water in the air, or in your skin or anywhere it can and form calcium hydroxide. This reaction is exothermic so it releases a lot of heat while it is reacting - there fore as well as being corrosive and causing significant skin irritation, calcium oxide's reaction with water can also cause burns. Calcium hydroxide is basically hydrated calcium oxide. It is alkali so can be corrosive. In solution it makes limewater. CaO is not found pure in nature but rather is contained in various abundant minerals (i.e. calcite, aragonite, limestone, marble) but vary greatly in their purity (impurities usually include magnesia, iron, alumina, silica, sulfur). Of these iron and sulfur are most troublesome (i.e. where clarity is important in glass). Lime minerals vary in the degree of crystallization and cohesion of the crystalline mass and the homogeneity of the matrix. Calcium oxide is the principle flux in medium and high temperature glazes, beginning its action (within the glaze) around 1100C. It must be used with care in high-fire bodies because its active fluxing action can produce a body that is too volatile (melting if slightly overfired). Lime, or calcium oxide, is a principle ingredient in the production of Portland cement, the basis for most mortars and concrete. Hydrated or ‘slaked’ lime is the chemical calcium hydroxide. This chemical is also used in mortars. Both types of lime are strong bases and are also used in food production (calcium hydroxide is commonly used in making corn tortillas), petroleum refining and sewage treatment. In the household it is used by aquarium hobbyists to add bioavailable calcium to fish tanks. It is also found in hair relaxers.

HistoryCalcium oxide dates from prehistoric times. It is produced by heating limestone to drive off carbon dioxide in a process called calcination: CaCO3(s) CaO(s) + CO2(g). At temperatures of several hundred degrees Celsius, the reaction is reversible and calcium oxide will react with atmospheric carbon dioxide to produce calcium carbonate. Efficient calcium oxide production is favored at temperatures in excess of 1,000°C. In prehistoric times limestone was heated in open fires to produce lime. Over time, lined pits and kilns were used to produce lime. Brick lime kilns were extensively built starting in the 17th century and the technology to produce lime has remained relatively constant since then.

UsesThe major uses of lime are metallurgy, flue gas desulfurization, construction, mining, papermaking, and water treatment. About one third of calcium oxide production in the United States is used for metallurgical processes, principally in the iron and steel industry. Calcium oxide is used to remove impurities during the refining of iron ore. Calcium oxide combines with compounds such as silicates, phosphates, and sulfates contained in iron ores to form slag. Lime is also used for purification in other metal refining and to control pH in mining processes such as leaching and precipitation. The calcium oxide is also used in remediation of mine wastes to recover cyanides and to neutralize acid mine drainage.

UsesCalcium Oxide is a general food additive consisting of white granules or powder of poor water solubility. it is obtained by heating limestone (calcium carbonate) in a furnace. it is also termed lime or quicklime. it is used as an anticaking agent, firming agent, and nutritive supple- ment in applications such as grain products and soft candy.

UsesIn bricks, plaster, mortar, stucco and other building and construction materials; manufacture of steel, aluminum, magnesium, and flotation of non-ferrous ores; manufacture of glass, paper, Na2CO3 (Solvay process), Ca salts and many other industrial chemicals; dehairing hides; clarification of cane and beet sugar juices; in fungicides, insecticides, drilling fluids, lubricants; water and sewage treatment; in laboratory to absorb CO2 (the combination with NaOH is known as soda-lime, q.v.).

General DescriptionCalcium oxide appears as an odorless, white or gray-white solid in the form of hard lumps. A strong irritant to skin, eyes and mucous membranes. Used in insecticides and fertilizers.