Chromium
| Chemical formula | {{#Chem:Cr}} |
|---|---|
| Atomic Number | 24 |
| OTP appearance | solid |
| Density(g/cc) | 7.2 |
| Melting Point(°C) | 1907 |
| Boiling Point(°C) | 2671 |
| Coefficient of Thermal Expansion(×10-6 °C-1) | 4.9 |
| NFPA 704 |  1
2
1
|
Uses
Primary
- Stainless steel
- High speed steel
- Electroplating
Secondary
- Tanning
- Cleaning glassware via chromic acid
- Combined with Nickel for heating elements
Natural Occurrence
- Elemental chromium does not occur naturally
- Iron chromium oxide ({{#Chem: FeCr2O4}}) occurrs as the mineral Chromite
- Lead chromium oxide ({{#Chem: PbCrO4}}) occurrs as the mineral Crocoite
Hazards
Chromium is toxic and carcinogenic in its hexavalent state. Production of chromium metal often takes a path through (VI) to separate other materials, only to reduce it to (III) later. This makes chromium production via this path very dangerous.
Production
===Extraction See chromium procesing for details on extracting both the pure metal and its various salts from naturally occurring chromite