Name | Sodium hydroxide |
Synonyms | soda lye Caustic soda lye, caustic white caustic flake caustic sodium hydrate Sodium hydroxide caustic soda solid solid caustic soda Caustic soda flake caustic soda pearls Liquid Caustic Soda caustic soda flakes Solid Sodium hydroxide Granular sodium hydroxide Food Additives Sodium Hydroxide |
CAS | 1310-73-2 8012-01-9 |
EINECS | 215-185-5 |
InChI | InChI=1/Na.H2O/h;1H2/q+1;/p-1/rHNaO/c1-2/h2H |
Molecular Formula | NaOH |
Molar Mass | 41.0045 |
Melting Point | 318℃ |
Boling Point | 100°C at 760 mmHg |
Water Solubility | SOLUBLE |
Vapor Presure | 24.5mmHg at 25°C |
Physical and Chemical Properties | The Pure product is a colorless and transparent crystal. |
Use | Basic chemical raw materials, used as high purity reagents, widely used in chemical, metallurgy, Paper, Petroleum, textile and daily chemical industry and other sectors. Used in the manufacture of soap, paper, rayon, finishing cotton, refined kerosene |
Hazard Symbols | C - Corrosive |
Risk Codes | R35 - Causes severe burns |
Safety Description | S24/25 - Avoid contact with skin and eyes. S37/39 - Wear suitable gloves and eye/face protection S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) |
UN IDs | UN 1823 |
pure sodium hydroxide is a white solid, easily soluble in water, its aqueous solution has astringent and smooth feeling. Sodium hydroxide is easy to absorb moisture when exposed to air, and the surface is wet and gradually dissolved. This phenomenon is called deliquescence. Its relative density is 2. 130. Melting point 318.4 °c. Boiling point 1390 °c. There are solid and liquid two kinds of commercially available caustic soda: pure solid caustic soda is white, block, Flake, Rod, granular, brittle; Pure liquid caustic soda is colorless transparent liquid. Solid caustic soda has strong hygroscopicity. Soluble in water, soluble exothermic, alkaline aqueous solution, a smooth feeling; Soluble in ethanol and glycerol; Insoluble in acetone, ether. It is highly corrosive to fibers, skin, glass, ceramics, etc. With the metal aluminum and zinc, non-metallic boron and silicon and other reactions to release hydrogen; With chlorine, bromine, iodine and other halogen disproportionation reaction; Neutralization with acids and the formation of salt and water.
There are two methods for the industrial production of caustic soda: causticization and electrolysis. Causticization method can be divided into soda causticization method and trona causticization method according to different raw materials. Electrolysis method can be divided into diaphragm electrolysis method and ion exchange membrane method.
Soda ash causticization method: the soda ash and lime are respectively made into soda alkali solution, and the ash is made into lime milk. The causticization reaction is carried out at 99~101 ℃, and the causticization solution is clarified, liquid caustic soda was prepared by evaporation and concentration to more than 40%. The concentrated liquid is further concentrated and solidified to prepare a solid caustic soda product. The causticizing mud was washed with water, and the washing water was used for alkalizing.
Trona causticization method: Trona is pulverized, dissolved (or alkali halide), clarified, and then added with lime milk at 95~100 ℃ for causticization, and the causticized solution is clarified and concentrated by evaporation to a NaOH concentration of about 46%, the clear liquid is cooled and further concentrated after salt analysis to prepare a solid caustic soda product. The causticized mud is washed with water and the wash water is used to dissolve the Trona.
Diaphragm electrolysis method: Add soda ash, caustic soda, barium chloride fine preparation to remove calcium, magnesium, sulfate ion and other impurities after the original salt, and then add sodium polyacrylate or causticized Bran in the clarification tank to accelerate the precipitation, after sand filtration, hydrochloric acid is added for neutralization, the brine is preheated and sent to electrolysis, and the electrolyte is preheated, evaporated, partitioned and cooled to prepare liquid caustic soda, which is further concentrated to obtain solid caustic soda product. The salt mud is washed with water for salt reduction.
Ion exchange membrane method: after the original salt is refined by the traditional method, the primary refined salt water is filtered through the microporous sintered carbon tubular filter, and then the secondary purification is carried out by the chelating ion exchange resin tower, the content of calcium and magnesium in the salt water is reduced to 0. 002% or less, the secondary refined brine is electrolyzed to generate chlorine in the anode chamber, and Na + in the brine in the anode chamber enters the cathode chamber and OH-in the cathode chamber through the ion-exchange membrane to generate sodium hydroxide. H + is directly discharged on the cathode to generate hydrogen gas. In the electrolysis process, an appropriate amount of high purity hydrochloric acid is added to the anode chamber to neutralize the returned OH-, and the required pure water should be added to the cathode chamber. The concentration of high purity caustic soda generated in the cathode chamber is 30% ~ 32% (mass), which can be directly used as a liquid alkali product or further concentrated to prepare a solid caustic soda product.
This product contains total alkali as sodium hydroxide (NaOH) calculation, should be 97.0% ~ 100.5%; Total alkali sodium carbonate (Na2C03) shall not exceed 2.0%.
for paper, cellulose pulp production; For soap, synthetic detergent, synthetic fatty acid production and refining of animal and vegetable fats and oils. Textile printing and dyeing industry is used as Cotton Desizing agent, refining agent and filament agent. The chemical industry is used to produce borax, sodium cyanide, formic acid, oxalic acid, phenol, etc. The petroleum industry is used to refine petroleum products and in oil field drilling mud. It is also used in the production of aluminum oxide, metal zinc and metal copper surface treatment and glass, enamel, leather, medicine, dyes and pesticides. Food grade products in the food industry to do acid neutralizer, can be used for citrus, peach and other peeling agent, as well as decolorizing agent, deodorant.
identification reaction of sodium salt in aqueous solution of this product (General rule 0301).
flush with water or saline for 15 min, then click into 2% Novocaine. Severe cases were sent to the hospital for treatment. The maximum allowable concentration of caustic soda dust in air is 0. 5mg/m3. Operators must wear work clothes, masks, protective glasses, rubber gloves, rubber aprons, long rubber boots and other labor protection articles. Should be applied to the skin with neutral and hydrophobic ointment. The production workshop should be well ventilated. Industrial solid caustic soda shall be packed in iron drum or other sealed containers, with barrel wall thickness of more than 0. 5mm and pressure of more than 0. 5Pa. The Lid must be tightly sealed, with net weight of 200kg per barrel and caustic soda of 25kg. The package shall be marked with "corrosive items. Edible liquid caustic soda with the tank car or tank shipment, after two times of use must be cleaned. It is not allowed to use the tank car or storage tank or barrel to transport edible liquid caustic soda produced by Mercury electrolysis. It is allowed to use plastic barrels and tanks that meet the requirements of food packaging standards to ship edible liquid caustic soda or caustic soda. The package should have obvious "food additives" and "corrosive substances" signs. Belongs to the first class of inorganic alkaline corrosion articles, risk code number: GB 8.2 class 82001. UN N0.1832; IMDG CODE 8226, P. 8.2, category 1. Should be stored in a ventilated, dry warehouse or shed. Packaging containers should be complete and sealed. They shall not be co-stored with flammable materials and acids. Attention should be paid to moisture and rain during transportation. If the packaging container is found to be corroded, broken, perforated, and dissolved water, the packaging should be replaced immediately or used as soon as possible. The damage of the container can be repaired by soldering. Fire, can use water, sand and all kinds of fire extinguishing, but the fire personnel should pay attention to the corrosion of the water dissolved in the caustic soda.
take this product, add water to dissolve into a solution containing 0. lmg per lm l, and determine according to law (General rule 0631),p H value shall not be less than 11.0.
take this product l.O g, add water to dissolve 20ml, check according to law (General rule 0901 and general rule 0902), the solution should be clear and colorless.
take this product 0.50g, check according to law (General rule 0801) and standard sodium chloride solution 2 .5m l made of control liquid comparison, not more concentrated (0.005%).
take this product l.O g, check according to law (General rule 0802), compared with the standard potassium sulfate solution 1 .5m l made of the control solution. Not more concentrated (0.015%).
take 0.25g of this product, add 5ml of water to dissolve it, add acetic acid to make it acidic, cool it in an ice bath, and add several drops of sodium nitrite dihydrate test solution to prevent turbidity.
take this product 5. O g, add 50ml of dilute hydrochloric acid to dissolve, boil, cool, add ammonia test solution to make it alkaline, filter, wash filter residue with 500ml of water, and burn to constant weight, and leave residue not to pass 5mg.
take this product l.O g, add 10ml of water and hydrochloric acid 2 .5m l after dissolution, add water to make 2 5 m l, check according to law (General rule 0807) and standard iron solution l.O tn l should not be more concentrated (0.001%) than the control solution.
take this product l.O g, add 5M l of water and 11ml of dilute hydrochloric acid to dissolve, boil, cool, add 1 drop of phenolphthalein indicator solution and appropriate amount of ammonia test solution to make the solution light red, add acetate buffer (pH 3). 5 )2M l and water to a proper amount of 0821, according to the law inspection (general principles the first law), containing heavy metals shall not exceed 20 parts per million.
take 1.5g of this product, precision weighing, add new boiling cold water 40ml to dissolve, let cool to room temperature, add phenolphthalein indicator solution 3 drops, with sulfuric acid titration solution (0 .5M o l/L) titration until the red color disappeared, record the volume of sulfuric acid titration solution consumed, add 2 drops of methyl orange indicator solution, and continue to add sulfuric acid titration solution to the persistent orange red color. Based on the volume of sulfuric acid titrant consumed, calculate the total amount of alkali in the test volume (calculated as NaOH), and based on the volume of sulfuric acid titrant consumed after adding methyl orange indicator solution, the content of Na2C03 in the Test amount was calculated. Each l of sulfuric acid titrant (106 mol/L) corresponds to 40. 00MG of NaOH or mg of Na2C03.
pharmaceutical excipients, p H value regulator.
sealed storage.