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Send EmailE529, Calcium Oxide, Lime, Calcia, airlock, bellcml, LIME,CAUSTIC, CALCIUM (II) OXIDE, calcium quick lime, Calcium oxide powder, 1305-78-8
Calcium oxide
CAS: 1305-78-8
Molecular Formula: CaO
Names and Identifiers
Physico-chemical Properties
| Molecular Formula | CaO |
| Molar Mass | 56.08 |
| Density | 3.3 g/mL at 25 °C (lit.) |
| Melting Point | 2570 °C |
| Boling Point | 2850 °C (lit.) |
| Flash Point | 2850°C |
| Water Solubility | REACTS |
| Solubility | 1.65g/l Risk of violent reaction. |
| Appearance | powder |
| Specific Gravity | 3.3 |
| Color | White to yellow-very slightly beige |
| Exposure Limit | ACGIH: TWA 2 mg/m3OSHA: TWA 5 mg/m3NIOSH: IDLH 25 mg/m3; TWA 2 mg/m3 |
| Merck | 14,1686 |
| PH | 12.6 (H2O, 20℃)(saturated solution) |
| Storage Condition | no restrictions. |
| Stability | Stability Stable, but absorbs carbon dioxide from the air. Incompatible with water, moisture, fluorine, strong acids. |
| Sensitive | Air & Moisture Sensitive |
| Refractive Index | 1.83 |
| Physical and Chemical Properties | Character White cubic powder. Industrial products often contain impurities such as magnesium oxide, aluminum oxide and iron oxide and dark gray, light yellow or brown. melting point 2614 ℃ boiling point 2850 ℃ relative density 3.25~3.38 soluble in acid. |
| Use | For the manufacture of calcium carbide, soda ash, bleaching powder, etc., but also for leather, wastewater purification |
Risk and Safety
| Risk Codes | R34 - Causes burns R41 - Risk of serious damage to eyes R37/38 - Irritating to respiratory system and skin. |
| Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S25 - Avoid contact with eyes. S39 - Wear eye / face protection. |
| UN IDs | 1910 |
| WGK Germany | 1 |
| RTECS | EW3100000 |
| FLUKA BRAND F CODES | 10-21-34 |
| TSCA | Yes |
| HS Code | 28259019 |
| Hazard Class | 8 |
| Packing Group | III |
Upstream Downstream Industry
Nature
White crystalline lumps or granules, powder. Melting point 2572 ℃; Boiling point 2850 ℃;d 3.32~3 35. Soluble in acid, glycerol, sugar solution, water-soluble, insoluble in ethanol. Easy to absorb carbon dioxide and moisture in the air. Calcium hydroxide is formed in contact with water and a large amount of heat is released. There are no specific combustion and explosion characteristics. It has strong corrosion. With acid substances can occur violent reaction.
Preparation Method
limestone calcination method: limestone is coarse-crushed to 150mm, and fine slag of 30 to 50mm or less is removed by sieve. Anthracite or coke required particle size of less than 50mm, which contains low melting point ash should not be too much, the addition of anthracite or Coke is 7.5% to 8.5% of limestone. The screened limestone and fuel are added into the kiln from the top of the kiln regularly and quantitatively, calcined at 900~1200 ℃, and then cooled to obtain a finished product. In the calcination process by-product carbon dioxide.
Standard
This product shall be calculated by burning to constant weight, and the CaO content shall not be less than 98.0%.
Trait
- This product is white or off-white lumps, granules or powder, odorless.
- This product is almost insoluble in ethanol and boiling water.
Use
Analytical reagents. For the preparation of high purity calcium salt, carbon dioxide absorbent, the preparation of the fluorescent powder flux and vegetable oil decolorizing agent. Can also be used in electronics, instrumentation, metallurgical industry.
Differential diagnosis
- take l g of this product, add several drops of water to wet, show exothermic phenomenon, the sample becomes loose, add 5ml of water, stir, paste and make the pH test paper alkaline.
- this product should show the flame reaction of calcium salt (General rule 0301).
Safety
This product is a strong alkali, irritation and corrosion. Has a strong irritation to the respiratory tract, inhalation of this product dust can cause chemical Pneumonia. Eye and skin have a strong irritation, can cause burns. Oral irritation and Burns of the digestive tract. Staff should be protected and immediately rinsed with running water after touching the eyes and skin. Store in a cool, ventilated warehouse. Prevent moisture and rain. Do not mix with acids for storage and transportation. When fire occurs, dry powder, carbon dioxide and dry sand should be used to extinguishing the fire.
Exam
insolubles in acid
Take 5.0g of this product, add several drops of water to wet it, then add water to lOOrnl, stir well, adjust to acid with hydrochloric acid, add hydrochloric acid to lm l, and boil for 5 minutes, filter with No. 4 vertical melting glass Crucible dried to constant weight at 105, and wash the filter residue with boiling water until the washing solution and silver nitrate solution are not turbid. Dry to constant weight at 105, and the remaining residue shall not pass through 10 .0m g(0 .2%).
carbonate
take l .O g of this product, add a few drops of water to wet, then add 50ml of water, stir, add an excess of dilute nitric acid, no bubbles.
magnesium and alkali metals
take 1.0g of this product, Add 75ml of water to dissolve, adjust to acidic with hydrochloric acid, add 1 ml of human hydrochloric acid, boil for 1-2 minutes, add human ammonia test solution to neutralize, add excess ammonium oxalate test solution, heat on a water bath for 2 hours, let it stand cold, add water to 200ml, stir well, filter, take 50ml of filtrate, add 0.5ml of sulfuric acid, evaporate on a water bath, flash to constant weight at 600C, the remaining residue should not exceed 15mg.
burning residue
take this product l.O g, check according to law (General rule 0841), burn to constant weight at 900°C, loss of weight shall not exceed 10.0%.
Content determination
take 0.4g of this product, weigh it accurately, put it in 250ml measuring flask, add hydrochloric acid solution (l -3 ) 8 m l, ultrasonic treatment (about 10 minutes) to dissolve, cool, dilute to the scale with water, shake well, take 10ml precisely, add 50ml of water and 2 m l of 8 m o L/l potassium hydroxide solution, and add 5mg of calcium carboxylic acid indicator, with ethylenediamine tetraacetic acid disodium titration solution (0. 02mol/L) titration to the solution from red wine to blue-green. Each l of l of ethylenediamine tetraacetic acid sodium titration solution (0.02 mol/L) is equivalent to 1.122 mg of CaO.
Category
pharmaceutical excipients, diluents and alkalizing agents.
Storage
sealed storage.
Reference Information
| What is calcium oxide? | calcium oxide is an inorganic compound, its chemical formula is CaO, common name lime. The physical properties are white powder on the surface, and those that are impure are gray-white. When impurities are contained, they are light yellow or gray, and have hygroscopicity. Calcium oxide is an alkaline oxide that is sensitive to moisture. Easy to absorb carbon dioxide and moisture from the air. It reacts with water to form calcium hydroxide (Ca(OH)2) and generates a large amount of heat, which is corrosive. calcium oxide is also an inorganic water scavenger that reacts with water to produce calcium hydroxide and also absorbs carbon dioxide. Calcium oxide powder can be added to some special sealants, water-Curable Adhesives and other systems. Calcium oxide can be used as an analytical reagent, gas analysis as a carbon dioxide absorbent, spectral analysis reagent, high purity reagent for semiconductor production in the epitaxial, diffusion process, laboratory ammonia drying and alcohol dehydration. |
| Application | quicklime is usually calcined from limestone, which has been used for a long time to make desiccant due to its excellent water absorption, the main component of quicklime desiccant is calcium oxide, and the drying principle is that calcium oxide absorbs water to generate calcium hydroxide, which is widely used in food, clothing and other industries because of its low cost and high cost performance. quicklime is usually calcined from limestone. Quicklime has long been used as a desiccant for its excellent water absorption properties, the drying principle is that calcium oxide reacts to generate calcium hydroxide, which is widely used in food, clothing and other industries because of its low cost and high cost performance. |
| identification test | take 1g of sample, shake with 20ml of water, add acetic acid test solution (TS-1) to dissolve the sample. This solution was positive for calcium test (IT-10). |
| content analysis | approximately 1g of sample was burned to constant weight (accurately weighed) and dissolved in 20ml of dilute hydrochloric acid solution (TS-117). After cooling, dilute to 500.0 with water and mix well. 50.0ml of this solution was placed in a suitable container and 50ml of water was added. Add about 30ml of 0.05mol/L disodium EDTA through a 50ml Burette with stirring (preferably with a magnetic stirrer), then add 15ml of sodium hydroxide solution (TS-224) and 300mg of hydroxynaphthol blue indicator, titration was continued to the blue end point. EDTA corresponds to calcium oxide 2.804mg per Ml of 0.05mol/L. |
| toxicity | ADI is not restrictive (FAO/WHO,2001). GRAS(FDA,§ 18.5210;§ 184.12, Lo, 2000). see calcium oxide. can stimulate the mucous membrane, cause sneezing, especially can make fat saponification, by the skin to absorb water, dissolve protein, irritation and corrosion of tissue. Strong effect on ocular mucosa. It can cause superficial ulcers in the oral and nasal mucosa, and sometimes perforation of the diaphragm in the nose and deep breathing tract. Pneumonia may be caused by inhalation of lime dust. If the dust is inhaled, the water vapor can be inhaled (some citric acid crystals can be added to the water in advance), and the mustard paste is applied to the thorax. If falling eyes can open eyes, immediately rinse with running water for 10~30 min and then rinse with 5% ammonium chloride solution. Mineral or vegetable oils containing 5% citric acid, tartaric acid, acetic acid, or salt solution lotions may be used to remove lime residues from the skin when it is burned. The maximum allowable concentration is 5 mg/m3 in the United States. Attention should be paid to the protection of respiratory organs, the use of dust-proof fiber made of work clothes, gloves, sealed dust-proof glasses. Apply oily ointment. Clean after work. In the preparation and use of dust to prevent inhalation. |
| usage limit | GB 14880-94 (in Ca, g/kg): beverages, cereals and their products, 1.6~3.2; Infant food, 3.0~6.0.GB 2760-2001: water preparation 100mg/L (36mg/L in Ca). |
| Use | used in the manufacture of calcium carbide, soda ash, bleaching powder, etc., used as building materials, refractory materials, desiccant, soil conditioner and calcium fertilizer used as analytical reagent and flux in the manufacture of fluorescent powder used in the manufacture of calcium carbide, soda ash, bleaching powder, etc, waste water purification and other used as building materials, metallurgical flux, is the main raw material for the preparation of calcium hydroxide and various calcium compounds, but also cheap alkali in the chemical industry. Widely used in pesticide, paper, food, petrochemical, leather, wastewater purification and so on. It can also be used for the drying of ammonia in the laboratory and the removal of l water from alcohols. for drug carriers. analysis reagent, calcium oxide used in iron and steel, pesticides, pharmaceuticals, non-ferrous metals, fertilizer, leather, calcium hydroxide, laboratory ammonia drying, carbon dioxide absorbent, alcohol dehydration. |
| production method | calcium carbonate calcination method calcium carbonate is reacted with hydrochloric acid to form calcium chloride, and then ammonia water is added for neutralization, the precipitate is allowed to stand and filtered, and then sodium bicarbonate is added to react to form calcium carbonate precipitate, which is dehydrated by centrifugal separation, dried, calcined, pulverized and screened to obtain a medicinal calcium oxide product. Its CaCO3 + 2HCl → CaCl2 + CO2 + H2O2 CaCl2 +2NH3? H2O → Ca(OH)2+2 NH4ClCa(OH)2 + NaHCO3 → CaCO3 + NaOH + H2O oco3 [Δ] → CaO + CO2 limestone calcination method the limestone was crushed to 150, and remove the fine slag of 30~50mm or less. Anthracite or Coke particle size is required to be less than 50 mm, which contains low melting point ash should not be too much, the addition of anthracite or Coke is 7.5% ~ 8.5% (weight) of limestone. The screened limestone and fuel are added into the kiln from the top of the kiln regularly and quantitatively, calcined at 900~1200 ℃, and then cooled to obtain a finished product. In the calcination process by-product carbon dioxide. CaCO3 [Δ] → CaO + CO2 ↑ |
| category | corrosive article |
| toxicity grade | poisoning |
| Acute toxicity | intraperitoneal-mouse LD50: 3059 mg/kg |
| explosive hazard characteristics | is corrosive to skin; Powdered calcium oxide can be explosive when mixed with water; Mixture with alcohol is heated and burned, explosion |
| flammability hazard characteristics | exothermic when exposed to water; The heat can make organic matter burn; One of the atmospheric pollutants; mixture with alcohol can be burned by heating |
| storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; It is stored separately from combustible materials, acids and phosphorus pentoxide. |
| fire extinguishing agent | water and sand mist |
| Occupational Standard | TLV-TWA 2 mg/m3; Tel 5 mg/m3 |
| immediate life-threatening and health concentration | 25 mg/m3 |
