Product categories

• Sodium Dichromate Used for Printing
• Sodium Dichromate Used for Tanning
• Chemical Reagent Sodium Dichromate
• Chemical Materials Grade Sodium Dichromate
• Medical Grade Sodium Dichromate 钠
• Industrial Grade Sodium Dichromate
 

 

1．Physicochemical Property
Chinese name: 重铬酸钠 English name: sodium dichromate
Alternative name: sodium bichromate Chemical formula: Na2Cr2O7·2H2O
Relative molecular mass: 297.99 Type of chemicals: inorganic substance—dichromate—sodium salt
Type of control: sodium dichromate (poisonous) Storage: store it in closed and dry place
Appearance and character: nacarat crystal, easy deliquescence
Melting point (℃)：357（anhydrous） Relative density: (water=1): 2.35
Boiling point (℃)：400（anhydrous） Molecular formula: NaCrO·2HO
Solubility: soluble in water, and insoluble in alcohol.

 

2．Chemical Property
Easy deliquescence and pulverization. As a strong oxidant, it can cause combustion when it contacts, rubs and hits against organic matters. It is corrosive and easily reduced to trivalent chromium. It is stable; the forbidden matching matters include strong reducing agent, alcohol, water, active metal powder, sulfur, phosphorus and strong acid; the condition that needs to be avoided to contact is moist air; polymerization hazard: non-polymerization.

 

 

3. Functions and Uses
It is used as the raw materials for production of chromic anhydride, potassium dichromate, ammonium dichromate, salt-based chromium sulfate, lead chromate yellow, copper chrome red, soluble chrome yellow, and chromium oxide green, and for production of oxidizing agent of alkaline acid blue dye, saccharin, synthetic camphor and synthetic fiber oxidants. In pharmaceutical industry it is used as an oxidizing agent for production of aminophenylsulfone, benzocaine, folic acid and Ethacridine lactate. In dyeing industry, it is used as oxidizing agent for coloring of aniline dyes, as the post-treatment agent for coloring of vulcanizing reduced dyes, and as the dye mordant for coloring of acid mordanting dye. In leather industry, it is used as a tanning agent. In electroplating industry, it is used for passivation after galvanizing to increase brightness. And in glass industry it is used as a green colorant.

 

 

4. Preparation Method
It is obtained from sodium chromate by acidification or electrolysis. In the industrial production, sulfuric acid method and electrolytic process are mainly used. Sulfuric acid method: at first evaporate the neutral solution of sodium chromate to a certain concentration, diluted with lotion, adding concentrated sulfuric acid to do acidification such that the sodium chromate is converted into the sodium dichromate. After evaporation twice, the sodium sulfate is completely removed, and then by clarification, take the clarified liquid to enable it to be cooled to 40℃ below, followed by crystallization, then it is obtained after solid-liquid separation.

 

5. Hazardous Characteristics
Strong oxidant. It can release oxygen in case it meets with strong acid or high temperature, thus to promote organic combustion. Severe reaction occurs when it contacts nitrate and chlorate. Mixing with sodium sulfide in water can cause spontaneous combustion. And there is risk of combustion explosion when it contacts or mixes with the organic matter, reducing agent, flammables such as sulfur and phosphorus. It has a strong corrosivity.

 

6. Emergency Treatment
Contacting skin: Remove the contaminated clothing and rinse thoroughly with soap and water.
Contacting eye: lift the eyelid, rinse it with running water or saline. Seeking medical treatment.
Inhalation: quickly go away from the site to a place with fresh air. Keep the airway open. If one’s breathing is difficult, oxygen shall be given. In case breathing stops, immediately perform artificial respiration. Seeking medical treatment.
Ingestion: rinse it with water and wash the stomach with water or conduct gastrolavage with 1% sodium thiosulfate solution. Drinking milk or taking egg white. Seeking medical treatment
Methods of fire fighting: using spray water and sand to put out the fire.
Emergency treatment: isolate the contaminated areas, and access to them is restricted. It is suggested that emergency personnel put on dust mask (full face mask) and wear noddy suit. Do not allow the spillage to contact with organic matters, reducing agents and flammables. Small amount of leaked matters are collected and put into dry, clean and covered containers with clean shovels. A large number of leaked matters shall be collected or transported to the waste disposal sites for disposal.