1．Physicochemical Property
Chinese Name: 三氧化铬 English name: Chromic anhydride
Alternative name: 铬酸酐; Chromium (VI) oxide Chemical formula: CrO₃
Molecular weight: 99.99 CAS RN: 1333-82-0
EINECS RN: 215-607-8
Melting point: 196℃ Boiling point: 2672℃ Water solubility: 1660g/L(20ºC)
Density: 2.7
Appearance: kermesinus orthorhombic crystal
Storage condition: indoor temperature
Shipping number of dangerous goods: UN1463
2．Chemical Property
It is slightly decomposed during fusing, and it gives out oxygen during decomposition at 200-250℃, with generation of an intermediate compound between chromium trioxide and chromium sesquioxide. It generates hyperoxide when contacting ozone. As a strong oxidant, it will cause combustion when contacting and rubbing against an organic matter. Combustion or explosion will occur as soon as it meets with ethyl alcohol and benzene.
3C2H5OH+2CrO3+3H2SO4 3CH3CHO+Cr2(SO4)3+6H2O
3．Functions and Uses
It is primarily used in production of inorganic industrial chromic compound, serving as oxidizing agent in printing & dyeing industry. It is used to produce zinc chrome and chromium oxide green, etc. in pigment industry and produce low-variance catalyst, medium-variance catalyst, oxidation catalyst and high-pressure process methyl alcohol catalyst, etc. In addition, it may be also used for wood preservation, production of waterproof agent and high purity chromium metal electrolysis.
In electroplating industry, it serves as a raw material of electrochromism for bicycle, sewing machine, instruments, flashlight and daily used hardware, etc.
4. Preparation Methods
(1) Sulfuric acid method: Heat and fuse sodium dichromate and sulfuric acid to conduct reaction. After the reaction and standing, separate the sodium bisulfate, followed by cooling, ejection, flaking and packaging, then the chromic anhydride is obtained.
(2) Heat chrome ore, sodium carbonate and limestone together, and then process them with concentrated sulfuric acid to obtain this product.
(3). Sulfuric acid method, nitric acid method, fluorosilicic acid method and electrolytic process.
5. Hazardous Characteristics
As a strong oxidizing agent, it will cause sharp reaction or even combustion when it meets with flammables (such as benzene) and combustibles (such as sugar and fibrin). When it is mixed with the matters with reducibility such as magnesite powder, aluminite powder, sulphur and phosphor, etc, it will cause combustion or explosion when it rubs with or hits against above-mentioned matters. It has relatively strong causticity.
Hazardous combustion products: they may probably generate harmful gray toxic smoke.
Method of extinguishing: using spray water and sand to put on a fire.
Help-oneself method: keep away from it and go to a place with ventilation opening.
6. Emergency Treatment
Contaminated areas are isolated and access to them is restricted. It is suggested that emergency personnel put on dust mask (full face mask) and wear noddy suit. They shall not directly contact the leaked matters, and the leaked matters are not allowed to contact organic matters, reducing agent and inflammables. For a small amount of leaked matters, collect and put them into dry, clean and covered containers with clean shovels. For a large number of leakages, wash them with water, with the diluted washing water being drained into wastewater system. The large amount of leaked matters shall be collected and recycled or transported to the waste treating sites for disposal.
7. Product Classification
Chromic anhydride used for coloring
Chromic anhydride used for mordanting
Chromic anhydride used for tanning
Chromic anhydride used for anticorrosion
Chromic anhydride used for hardware protection
Chromic anhydride used for surface treatment
Chromic anhydride used as chemical reagent
Industrial grade chromic anhydride
8. Fields
Printing-Dyeing and Pigments
Textile and Tanning
Electroplating and Anticorrosion
Chemical Materials
New Energy- New Products
