英语论文网

Abstract
The Pilbara is a mining region located around 1,100 km north of Perth, in Western Australia. Iron ore is the major commodity mined in the Pilbara. The Pilbara is a major supplier of iron ore to steel industries in Asia and Europe.
BHP Billiton and Rio Tinto are the major iron ore producing companies in the region and in June 2009 agreed to a joint venture to combine all of both companies' iron ore assets in Western Australia.The joint venture has the potential to create an unrivalled and dominant iron ore business throughout the region and the world.
Rio Tinto's Pilbara iron ore operations include 11 mines, three shipping terminals and a privately owned heavy freight rail network, with an annual capacity of 220 million tonnes. BHP Billiton Iron Ore owns seven iron ore operations, including the world's largest single-pit open-cut iron ore mine, two separate single track rail systems and two separate port operations in the Pilbara. 

Introduction
The Pilbara is a 510,000 square-kilometre mining region located around 1,100 km north of Perth, in Western Australia Iron ore is the major commodity mined in the Pilbara, producing over 96 per cent of Australia's iron ore exports. Iron ore production for the region in 2004/05 was worth approximately $8 billion . The major iron ore producing companies in the region are BHP Billiton and Rio Tinto. In June 2009 BHP Billiton and Rio Tinto agreed to a joint venture to combine all of both companies' iron ore assets in Western Australia.
Geology
The Pilbara region contains the 80,000 square-kilometre Hamersley Iron Province. The Province is characterized by the ‘Hamersley Group', a group of late Archaean and early Proterozoic rock formations. During the formation of the Hamersley Group, different types of rocks were deposited in layers. This resulted in iron-rich layers being deposited alternately with silica-rich layers. This is known as Banded Iron Formation (BIF). Unenriched layers of BIF are usually uneconomical and contain around 30 percent iron 
Pilbara Mining
Bedded iron deposits are formed due to the natural enrichment of BIF. A number of the commercially viable deposits in the Pilbara, including the Brockman and Marra Mamba Iron Formations, were formed by this natural enrichment. The natural enrichment process of the BIF involved circulating ground waters. Hydrous iron oxides, such as goethite, replaced non-iron minerals and magnetite oxidised to haematite 
Channel Iron Deposits
Channel Iron Deposits (CIDs) in the Pilbara were formed by iron particles being concentrated in ancient river channels. The iron particles were deposited into the river channels by the weathering and erosion of bedded iron deposits. These particles were rimmed and fused by goethite which was deposited by iron-enriched ground water CIDs occur as mesas, small flat-topped hills, which can range from about 5 40 metres in thickness. 
Detrital Iron Deposits
Detrital iron deposits (DIDs) are formed by the deposition of ore fragments into natural structures such as valleys and drainage channels. The ore fragments are formed by the weathering and erosion of bedded iron deposits. DIDs can occur as naturally cemented or as loose gravels and in many deposits both types are present .<本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。