Platinum
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| Chemical formula | Pt |
|---|---|
| Atomic Number | 78 |
| OTP appearance | silvery solid |
| Molar Mass(g/mol) | 195 |
| Density(g/cc) | 21.45 |
| Melting Point(°C) | 1769 |
| Boiling Point(°C) | 4825 |
| Coefficient of Thermal Expansion(×10-6 °C-1) | 8 |
| NFPA 704 |  2
1
0
|
Along with gold, Platinum is classed as a noble metal because it is extremely unreactive. Platinum also has a very high melting point. This and its nonreactive nature make it an excellent catalyst and electrode. It is definitely not widely available.
Uses
Primary
- Catalysts, particularly for Ostwald production of nitric acid
- Feedstock for WHO LEM chemotheraputics including Cisplatin, Oxaliplatin, and Carboplatin, .
Other
- As an electrode
- As a catalyst
- As platinum black
Natural Sources
- Elemental platinum does occur naturally
- Elemental platinum occurs as an impurity in silver and gold
- Platinum exists in virtually all placer gold, but in ppm quantities:
- ... One dredging company, which recovered about 50,000 ounces of gold from 10,000,000 cubic yards of gravel, sold about 110 ounces of crude platinum metals; these contained 70 ounces of platinum (~1400ppm) and 6 or 8 (~140ppm) ounces each of iridium and osmium.[1]
- Platinum exists in virtually all placer gold, but in ppm quantities:
- Platinum appears as a minute impurity (3-6ppm, g/ton) in chalcopyrite and pentlandite.
Production
Extraction
From gold-platinum alloy
- Dissolve gold-platinum in aqua regia
- Slowly add enough iron (III) sulfate to precipitate all the gold
- Separate gold from solution and wash gold with hydrochloric acid
- Neutralize platinum solution, precipitating platinum.
See Also
- Lee, George E. (1920) "Recovering Precious Metals from Waste Liquid Residues".
SPON & CHAMBERLAIN, 120 LIBERTY STREET
Chapter XXXIV Separating Platinum from Gold
References
- ↑ Gardner, E. D.; Johnson, C. H. (1934) "Placer Mining in the Western United States"
United States Bureau of Mines Information Circular(6786)