详情描述

Calcium oxide, also known as quicklime, is an inorganic compound with the chemical formula CaO. It is characterized by a white powder surface, with impure forms appearing grayish-white, and can be pale yellow or gray when containing impurities. It is hygroscopic.

Calcium oxide applications:

1. Suitable as a filler, for example: used as a filler for epoxy adhesives.

2. Used as analytical reagents, absorbent for carbon dioxide in gas analysis, spectral analysis reagents, and high-purity reagents for epitaxy and diffusion processes in semiconductor production, as well as for drying ammonia in laboratories and dehydrating alcohols.

3. Used as raw material, it can produce calcium carbide, soda ash, bleaching powder, etc., and is also used in leather production, wastewater purification, calcium hydroxide, and various calcium compounds.

4. Used as construction material, metallurgical flux, cement rapid-set accelerator, and flux for phosphorescent powder.

5. Used as a decolorizer for vegetable oils, drug carrier, soil conditioner, and calcium fertilizer.

6. Also suitable for refractory materials, desiccants.

7. Offers 1 and 2 types of agricultural machinery adhesives, as well as underwater epoxy adhesive, which also serves as a reactant for pre-reacting with 2402 resin.

8. Used for acidic wastewater treatment and sludge conditioning.

9. Also serves as a boiler shutdown protector, utilizing the hygroscopic capacity of lime to keep the metal surfaces of the boiler's water-steam system dry, preventing corrosion. Suitable for long-term shutdown protection of low-pressure, medium-pressure, and small-capacity drum boilers.

10. Can react with water to produce calcium hydroxide, reaction equation: CaO + H₂O = Ca(OH)₂, which is a synthesis reaction.

Calcium oxide precautions:

1. Lime should not be exposed to the air for long periods as it absorbs carbon dioxide and turns into powdered calcium carbonate, thus losing its pond disinfection effect. Therefore, it's best to buy and use quicklime immediately, opting for lighter, block-shaped lime without impurities. If some lime remains unused, seal it in a plastic bag and store it in a sealed container.

2. Add calcium oxide to the slurry and sprinkle it while hot; avoid pouring the residue into the pond, as this may cause the fish to mistake it for food and die. Moreover, do not throw whole blocks of lime into the pond for water disinfection.

3. Calcium oxide should not be used simultaneously with nitrogenous fertilizers. Lime reacts with water to produce a large amount of OH-, causing the NH₄⁺ + OH⁻ ⇌ NH₃·H₂O equilibrium to shift to the right, leading to high ammonia content which can cause fish ammonia poisoning. Similarly, lime should not be added to ponds when the ammonia nitrogen content exceeds 1.2 mg/L. Additionally, lime should not be used within a week after applying ammonium nitrogen fertilizers; mixing them is strictly prohibited.

Calcium oxide should not be mixed with phosphate fertilizers. After applying phosphate fertilizers, inorganic phosphorus mainly exists in the form of HPO₄²⁻ and H₂PO₄⁻ at pH 6.5 to 7.5. When mixed with quicklime at pH above 7.5, a reaction occurs to form Ca(PO₄)₂, causing the phosphorus to precipitate as calcium salts and be lost. It is generally recommended to wait at least 10 to 15 days after applying quicklime before applying phosphate fertilizers.

5. Calcium oxide should not be mixed with bleaching powder, hypochlorous acid, and other halogen drugs. Since bleaching powder is an acidic drug and calcium oxide is an alkaline one, mixing them will neutralize the acidity and alkalinity, directly reducing the disinfection efficacy.

6. Calcium oxide should not be used simultaneously with dipterex. Because when quicklime comes into contact with water, it generates calcium hydroxide, and under weak alkaline conditions, dipterex undergoes a chemical reaction to form diazinon, which enhances its toxicity by 10 times and significantly extends the residual period.

7. Not suitable for co-administration with organic chelates. Water-soluble organic chelates can form insoluble complexes with calcium ions, reducing the efficacy of the chelate therapy.

8. Not to be used concurrently with copper sulfate and similar substances. An increase in hydroxide ions in the water body will cause a decrease in copper ions, significantly reducing the efficacy of copper sulfate. Similarly, quicklime should not be mixed with calcium, magnesium, or heavy metal salts.

Calcium oxide storage and transportation:

1. Shipping Precautions: Ensure the packaging is intact at the time of shipment and the loading is secure. During transportation, ensure containers do not leak, collapse, fall, or get damaged. Prohibit mixing and transporting with flammable or combustible materials, acids, edible chemicals, etc. Transport vehicles should be equipped with emergency leak handling equipment. Avoid transportation during rain.

2. Storage Precautions: Store in a cool, well-ventilated warehouse. The humidity within the warehouse should not exceed 85%. Packaging must be intact and sealed to prevent moisture absorption. Keep away from flammable materials, acids, etc., and avoid mixing storage. The storage area should be equipped with suitable materials to contain spills.