Sodium sulfide is also called stinky alkali, stinky soda, yellow alkali, and alkali sulfide. Sodium sulfide is an inorganic compound, and pure sodium sulfide is a colorless crystalline powder. It has strong moisture absorption and is easily soluble in water. The aqueous solution is strongly alkaline. It will cause burns when touching ~ and hair. So sodium sulfide is commonly called alkali sulfide. The sodium sulfide aqueous solution will slowly oxidize into sodium thiosesulfate, sodium sulfite, sodium sulfate and sodium polysulfide in the air. Since sodium thiosesulfate is produced faster, the main product of oxidation is sodium thiosesulfate. Sodium sulfide deliquescence in the air, and carbonation and deterioration, continuously releasing hydrogen sulfide gas. Industrial sodium sulfide is pink, brown-red, and ocher due to impurities. The specific gravity, melting point, and boiling point also vary due to the influence of impurities.

【Basic information】

【Physical and chemical properties】

Physical properties

Pure products are colorless or slightly purple prismatic crystals at room temperature, and industrial products are often pink, brown-red, or ocher due to impurities.

Has a bad smell. It is soluble in cold water, very soluble in hot water, and slightly soluble in alcohol. Industrial products are generally a mixture of crystal water in different shapes and contain different degrees of impurities. In addition to different appearance and color, the density, melting point, and boiling point are also different due to the influence of impurities.

Chemical nature

Decomposes in acid to generate hydrogen sulfide. Deliquescence in the air, while gradual oxidation occurs, and hydrogen sulfide is generated when encountering acid. It can explode by impact or high heat. When exposed to acid, toxic hydrogen sulfide gas is produced, and anhydrous alkali sulfide is flammable, and it emits toxic sulfur oxide smoke when heated.

Health hazards: This product can decompose hydrogen sulfide in the gastrointestinal tract, and can cause hydrogen sulfide poisoning after oral administration. Corrosive to ~ and eyes.

Hazardous characteristics: it can occur by impact or rapid heating. It decomposes in acid and emits highly toxic flammable gas.

Combustion (decomposition) products: hydrogen sulfide, sulfur oxide. Acute toxicity: LD50820mg/kg (mouse oral); 950mg/kg (mouse intravenous injection). Related chemical reaction equation: 2Na+S=Na2S.

【Application field】

1. It is used to produce sulfur dyes in the dye industry and is the raw material for sulfur blue and sulfur blue. The printing and dyeing industry is used as a dye assistant to dissolve sulfur dyes. In the tanning industry, it is used for hydrolysis to dehair the hides, and it is also used to prepare sodium polysulfide to accelerate the soaking of dry skins to help soften them. The paper industry is used as a cooking agent for paper. In the textile industry, it is used as a mordant for man-made fiber denitration and nitrification reduction, as well as for dyeing cotton fabrics. The pharmaceutical industry is used to produce antipyretics such as phenacetin. In addition, it is also used to make sodium thiosesulfate, sodium hydrosulfide, sodium polysulfide and so on.

2. Adding an appropriate amount of sodium sulfide to the alkaline etching solution for aluminum and alloys can* improve the quality of the etching surface, and it can also be used to remove alkali-soluble heavy metal impurities such as zinc in the alkaline etching solution.

3. Sodium sulfide can also be used for the treatment of the conductive layer in direct electroplating. The colloidal palladium sulfide is formed by the reaction of sodium sulfide and palladium to achieve the purpose of forming a good conductive layer on the non-metal surface.

4. Used as a corrosion inhibitor. It is also a raw material for sodium thiosesulfate, sodium polysulfide, sulfur dyes, etc.

5. Used in the manufacture of sulfur dyes, leather depilatory, metal smelting, photography, rayon denitration, etc.

【Precautions】

Entry route: inhalation and ingestion.

Respiratory system protection: Generally, special protection is not needed. Wear a gas mask when necessary.

Eye protection: a face mask can be used.

Protective clothing: wear anti-corrosion overalls.

Hand protection: wear rubber gloves. 

Contact: Rinse immediately with water for at least 15 minutes. If you have burns, seek medical attention.

Eye contact: immediately lift the eyelids, rinse with running water or saline for at least 15 minutes, or rinse with 3% boric acid solution.

Inhalation: Leave the scene to fresh air. Give artificial respiration if necessary.

Ingestion: give milk or egg white to those who mistakenly take it. Seek medical attention immediately.

Fire extinguishing method: misty water, sandy soil.

Others: After work, take a shower and change clothes. Pay attention to personal hygiene.

Leakage emergency treatment: Isolate the leaking contaminated area and set up warning signs around. Emergency treatment personnel wear gas masks and chemical protective clothing. Do not directly touch the leakage. Avoid dust, use a clean shovel to collect in a dry and clean covered container, and transport to the waste disposal site. It can also be washed with a lot of water, and the diluted lotion is put into the waste water system. If there is a large amount of leakage, collect and recycle or discard after harmless treatment.