Carajas Iron Ore Mine, Brazil

The Carajás Mine is the world's largest iron ore mine and is located in the state of Para in Northern Brazil.
Fully owned by Brazilian miner Vale (CVRD), the mine holds over 1.5 billion tons of iron ore in reserves.

The Carajas region boasts the richest reserves and concentrations of iron ore anywhere in the world and was discovered entirely by accident in the late 60s when a US Steel Helicopter was forced to land on a hill in the area to refuel. Surveyors on board noted the baron state of the hill and subsequently discovered that the iron content was as high as 66%.
Other mineral deposits were discovered later; Carajás is rich not only in iron ore but also ores for manganese, copper, tin, aluminium and even gold.
US Steel wanted to develop the Carajás iron deposit but the Brazilian Government was unwilling to hand control over to a foreign company. Brazil is currently the world's largest exporter of iron ore with annual production of over 200Mt.
In 1970 the Brazilian government opted instead to create a joint venture company, Amazonias Mineração SA (AMZA), of which 51% was owned by Vale and 49% was

US Steel subsequently withdrew from the joint venture in 1977 by selling its share to CVRD for $55m. Vale produced a record 296 million metric tons of iron ore at the Carajas Mine for 2007, a 12% rise on 2006. Vale is expected to announce in 2008 the results of a tender for the expansion of the Carajas mine. The $2.48bn project, "Carajas 130," will add 30 million tons a year to the current capacity of 100 million tons a year, the company says.
Geology and reserves
The Carajás ores are found within Archaean iron formations. The volcanic sequence has been weathered to a depth of between 100m and 150m, while oxidation is observed to a depth of up to 500m in the BIFs of the ore zone.
The upper 80% of the reserve comprises a soft, friable enriched limonite near surface passing down into hematite to a vertical depth of around 300m. Hematite rich, but harder and more siliceous pods occur within the soft hematite, but also as a transition to the un-enriched BIF at depth.
The Carajás District contains known reserves of the order of 18 billion tons with an average grade of 65.4% Fe. The reserves are distributed in a number of deposit groups, the largest of which is the North Range with - 6,200Mt @ 65.8% Fe, 0.038% P, 1.0% SiO2, 1.05% Al2O3, 0.45% Mn, 0.01% S, 0.02% KO, 0.03% Na2O and 1.88% LOI. The other reserves include: South Range, 35km to the south – 10,400Mt @ 66.3% Fe; East Ridge – 400Mt @ 65.9% Fe; and South Felix Ridge – 600Mt @ 62.8% Fe. The current production contains < 1% Al2O3, < 1% SiO2, < 0.03% P2O5 and < 0.3Mn, with about 10% lump and 90% fines.