Cobalt (Co)
| Atomic Number | 27 |
|---|---|
| Atomic Mass | 58.9331944 u |
| Category | Transition metal |
| Electron Config | [Ar] 3d⁷ 4s² |
| Appearance | hard lustrous gray metal |
| Density (STP) | 8900 g/L |
| Melting Point | 1768 K |
| Boiling Point | 3200 K |
| Electronegativity | 1.88 (Pauling) |
| Ionization Energy | 760.4 kJ/mol |
| Atomic Radius | 135 pm |
| Crystal Structure | Simple Hexagonal |
| Discovered By | Georg Brandt (1735) |
Brief Introduction
Cobalt (Co) is a hard, lustrous, silvery-blue transition metal that is ferromagnetic and maintains its magnetic properties at high temperatures. It is relatively rare but geopolitically significant. Key details about Cobalt (Co) are as follows:
Uses: Critical for lithium-ion batteries (especially in electric vehicles and smartphones), superalloys for jet engines and gas turbines, permanent magnets (AlNiCo, SmCo), catalysts (petroleum refining, chemical synthesis), blue pigments (cobalt blue), and in stellite alloys for cutting tools.
Production/Extraction: Primarily mined as a byproduct of copper and nickel extraction. The Democratic Republic of Congo (DRC) produces about 70% of global supply, raising ethical concerns over mining conditions. Also found in laterite and sulfide ores.
History: Cobalt compounds used for blue glass and ceramics since ancient times. Isolated as an element by Georg Brandt in 1735 in Sweden. Name derives from German "kobold" (goblin), as miners blamed troublesome underground spirits for arsenic-containing cobalt ores.
Health Effects & Safety: Cobalt is essential in trace amounts (component of vitamin B12). Excessive exposure causes lung disease (hard metal lung disease), cardiomyopathy, and other health effects. Cobalt-60 (radioactive isotope) is used in radiotherapy and sterilization. Some people develop allergic reactions to cobalt in metal implants.
Price/Market: Price extremely volatile and sensitive to battery demand and DRC political stability. Classified as a critical mineral due to supply concentration. Growing concerns about sustainable and ethical sourcing.
Properties: Ferromagnetic with high Curie temperature (1115°C), hard and brittle, resists oxidation, exhibits +2 and +3 oxidation states, forms intensely colored compounds (especially blue), and retains strength at high temperatures.
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