Chromium sesquioxide , AR,99.0% , 1308-38-9

Synonym(s):
Chromia

CAS NO.：1308-38-9

Empirical Formula: Cr2O3

Molecular Weight: 151.99

MDL number: MFCD00010949

EINECS: 215-160-9

PRODUCT Properties

• Melting point: 2435 °C
• Boiling point: 4000 °C
• Density: 5.21
• refractive index: 2.551
• Flash point: 3000°C
• storage temp.: Room Temperature
• solubility: Insoluble in all solvents
• form: powder
• color: Pale to dark green
• Specific Gravity: 5.22
• Odor: at 100.00?%. odorless
• Water Solubility: Insoluble
• Crystal Structure: Trigonal
• crystal system: Three sides
• Merck: 14,2234
• Space group: R3c
• Lattice constant:
  • a/nm: 0.496
  • b/nm: 0.496
  • c/nm: 1.359
  • α/o: 90
  • β/o: 90
  • γ/o: 120
  • V/nm3: 0.2895
• Exposure limits: NIOSH: IDLH 25 mg/m3; TWA 0.5 mg/m3
• Stability: Stable.
• CAS DataBase Reference: 1308-38-9(CAS DataBase Reference)
• NIST Chemistry Reference: Chromium(iii) oxide(1308-38-9)
• EPA Substance Registry System: Chromium(III) oxide (1308-38-9)

Description and Uses

Chromium(III) oxide is among the ten most abundant compounds in the Earth's crust. It is one of four oxides of chromium, chemical formula Cr2O3. It is commonly called "chrome green" when used as a pigment; however it was referred to as “viridian” when it was first discovered.

Chromium(III) oxide is a very refractory ceramic colorant (even a 50% mix with a high borax frit will not even begin to melt it in a crucible). Chrome oxide is the only stable oxide of the metal chromium. It is a bright to dark green crystalline powder insoluble in alkalis and acids. It is manufactured from the mineral Chromite mined in southern Africa, Asia, Turkey and Cuba. As with other powerful coloring agents, chrome must be milled fine enough to eliminate specking in glass or glaze.
Chromium is a "fast" colorant, meaning can produce strong green colors under all furnace conditions, slow or fast, reducing or oxidizing. It is also a flat colorant (due to its refractory nature), it usually produces an army helmet opaque green. It is powerful, typically only 2% will produce a dark color. It cannot be used to make a metallic glaze.
Chrome oxide is usually employed in raw glazes whereas potassium dichromate is used in fritted glazes.

Chromium oxide (Cr2O3) is a dull green synthetic inorganic pigment, which can be used in all types of paint systems where high chemical resistance and outstanding light-fastness are required.

Safety

• Symbol(GHS): GHS07
• Signal word: Danger
• Hazard statements: H302-H317-H332
• Precautionary statements: P261-P280g-P301+P312a-P304+P340-P321-P501a
• Safety Statements: 24/25
• WGK Germany: -
• RTECS: GB6475000
• TSCA: Yes
• HS Code: 28199090
• Hazardous Substances Data: 1308-38-9(Hazardous Substances Data)