What is the difference between effective calcium and calcium oxide in environmental lime kiln ?
In the production of environmentally friendly lime kiln , the commonly used quality indicators are "effective calcium" and "calcium oxide". What is the difference between the two?
The effective calcium oxide content is equal to or greater than the calcium oxide content. The calcium oxide content is a comprehensive analysis of quicklime, which includes impurities and raw burn. Removing the impurities and raw burn is the effective calcium oxide content. Here's the difference between the two!
Calcium oxide is an inorganic compound whose chemical formula is CaO, commonly known as quicklime. The physical properties are white powder on the surface, and the impure ones are off-white. It contains light yellow or gray when containing impurities, and has hygroscopicity.
Calcium oxide is an alkaline oxide and is sensitive to moisture. Easily absorb carbon dioxide and moisture from the air. Reacts with water to form calcium hydroxide (Ca (OH) 2) and generates a lot of heat, which is corrosive.
Effective calcium oxide is a chemical substance with the chemical formula CaO.
Determination of effective calcium oxide content in lime: Effective calcium oxide and other calcium in lime refer to free calcium oxide, and it does not include calcium carbonate, calcium silicate and other calcium in lime. The quality of lime depends on the effective calcium oxide content. The calcium oxide content of high-quality lime should reach 95%, while the low-quality lime should be less than 50%, and industrial use should reach 60%.
The effective calcium oxide in lime, referred to as "effective calcium", refers to the active calcium oxide that can be rapidly hydrolyzed to form calcium hydroxide. Due to the calcination temperature, some calcium oxide cannot quickly hydrolyze after contact with water, and still exists in the form of free calcium oxide. This kind of free calcium oxide in water is also called supercalcified calcium oxide. In addition, lime is generally It also contains a small amount of calcium compounds such as calcium silicate, calcium aluminate, and calcium ferrite. They are all inactive calcium salts, so they are not effective calcium.
1. The value of calcium oxide is the content of calcium oxide in the quicklime mixture; the effective calcium content is the content of calcium.
2. The effective calcium oxide content is equal to or greater than the calcium oxide content. The calcium oxide content is a comprehensive analysis of quick lime, which includes impurities and raw burns. Removing the impurities and raw burns is the effective calcium oxide content.
3. Calcination of limestone at high temperature to generate calcium oxide: CaCO3, high temperature CaO + CO2 ↑;
Reaction of calcium oxide with water: CaO + H2O = Ca (OH) 2;
Reaction of calcium oxide and dilute hydrochloric acid: CaO + 2HCl = CaCl2 + H2O;
The main uses of calcium oxide:
1. Can be used as a filler, for example: used as an epoxy adhesive filler;
2. Used as analytical reagents, used as carbon dioxide absorbents, spectral analysis reagents, high-purity reagents for epitaxial and diffusion processes in semiconductor production, laboratory ammonia drying and alcohol dehydration.
3. As raw materials, it can be used to manufacture calcium carbide, soda ash, bleaching powder, etc., also used in tanning, wastewater purification, calcium hydroxide and various calcium compounds;
4, can be used as building materials, metallurgical fluxes, cement accelerators, fluxes of phosphor powder;
5. Used as vegetable oil decolorant, drug carrier, soil improver and calcium fertilizer;
6, can also be used for refractory materials, desiccants;
7. For acid wastewater treatment and sludge conditioning;
8. It can also be used as a boiler deactivation protection agent, making use of the moisture absorption capacity of lime to keep the metal surface of the boiler water vapor system dry and prevent corrosion.
9. It can react with water to prepare calcium hydroxide. The reaction equation: CaO + H₂O = Ca (OH) ₂, which belongs to the compounding reaction.
Precautions for transportation: The package should be complete at the time of shipment, and the loading should be secure. During transportation, ensure that the container does not leak, collapse, fall, or damage. It is strictly prohibited to mix and transport with flammable or combustible materials, acids, edible chemicals, etc. The transportation vehicle should be equipped with leakage emergency treatment equipment during transportation. Not suitable for transportation on rainy days.
Storage precautions: Store in a cool, ventilated warehouse. The humidity in the warehouse is preferably not more than 85%. The packaging must be completely sealed to prevent moisture absorption. It should be stored separately from flammable (flammable) materials, acids, etc., and should not be mixed. The storage area should be equipped with suitable materials to contain spills.