Iron is used in greater quantities than any other metal. Despite the wide
distribution of iron in nature, comparatively few minerals are used as ore.
The principal ore minerals are as follows.
| Mineral |
Composition |
Iron
approx. %
|
| Magnetite |
Fe3O4 |
72
|
| Hematite |
Fe2O3 |
70
|
| Goethite |
Fe2O3.H2O |
62
|
| Limonite |
Mixture
of hydrated iron oxides |
50-60
|
| Siderite |
FeCO3 |
48
|
In natural
deposits, the percentages shown above are rarely attained because of the
presence of impurities such as silica, alumina, sulfur, and phosphorus.
Hematite ores are the most widely used, and many of the major hematite
deposits of the world can be mined at a grade of higher than 60% iron.
Our ores are beneficiable. For example, Magnetite can be separated cheaply
from the quartz and other impurities by magnetic separation. We also have
free-milling Hematite deposits which can be mined and upgraded by simple
gravity separation.
|
