|
|
|
Tungsten
Tungsten, formely Wolfram, is a very hard, heavy gray-white
transition metal, found in several ores including wolframite
((Fe,Mn)WO4, iron-manganese tungstate) and scheelite (CaWO4,
calcium tungstate).
Remarkable for its robust physical properties, the pure form
of this metallic element is used mainly in electrical applications.
Mixed with other metals, tungsten can make "supperalloys”
used in tubine engines for jet aircraft and energy generation
or in space-age superalloys. Mixed with carbon, "tungsten
carbide” is used to make cutting tools and wear-resistant
tool for metalworking, drilling for oil and gas, mining and
construction.
Tungsten is also used in light bulb filaments because it has
a very high melting point, a low vapor pressure and a resistance
in high temperatures situations.
Links: ITIA:
The International Tungsten Industry Association,
Wolfram
Bergbau- und Hütten-GmbH
World Tungsten Mine Production 2001-2003
| |
2001
|
2002
|
2003 estimated
|
| United States |
-
|
-
|
-
|
| Austria |
1.600
|
1.400
|
1.400
|
| Bolivia |
360
|
500
|
450
|
| Brazil |
14
|
15
|
-
|
| Burma |
71
|
70
|
-
|
| Canada |
-
|
2.550
|
3.000
|
| China |
37.000
|
49.500
|
49.500
|
| Korea, North |
700
|
600
|
600
|
| Portugal |
750
|
700
|
700
|
| Russia |
3.500
|
3.400
|
3.400
|
| Thailand |
30
|
50
|
-
|
| Other countries |
180
|
430
|
450
|
| World
Total |
44.200
|
59.100
|
59.500
|
Source: U.S. Geological Survey, Mineral Commodity Summaries,
January 2003 and January 2004
|
|
|
