New Zealand Steel
| Glenbrook Steel Mill | |
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 Glenbrook Steel Mill from the mill's lookout |
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| Official name | New Zealand Steel |
| Country | New Zealand |
| Location | Auckland |
| Coordinates | 37°13′S 174°44′E / 37.21°S 174.74°ECoordinates: 37°13′S 174°44′E / 37.21°S 174.74°E |
| Commission date | 1968 |
| Website http://www.nzsteel.co.nz/about-new-zealand-steel/operations-/glenbrook-steel-site |
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New Zealand Steel or the Glenbrook Steel Mill is a steel mill located 40 kilometres south east of Auckland in Glenbrook, New Zealand. The mill was constructed in 1968 and began producing steel products in 1970. Currently, the mill produces 650 000 tonnes of steel a year which is either domesticity used or exported[1][2]. Over 90% of New Zealand's steel requirments are produced at Glenbrook while the remaining volume is produced by Pacific Steel, a steel recycling facility in Otahuhu, Auckland. The mill is served by the Mission Bush railway branch, which was formerly a branch line to Waiuku. Coal and lime trains arrive daily. Steel products are also transported daily. The mill employs 1150 full time staff and 200 semi-permanent contractors.
New Zealand Steel is notable due to its unique[2][1] utilisation of ironsand as its ore. Because ironsand is a low grade ore with many contaminants, the mill's primary plants' operations and equipment are unusual[2].
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[edit] History
New Zealand Steel Limited was incorporated by the New Zealand Government in 1965. In 1967, construction started on a mill at Glenbrook[3]. Commercial operations began in 1968, with imported feed coil being used to produce steel for domestic and Pacific Island markets. The company had pioneered the direct reduction process for reducing iron oxide (ironsand) into metallic iron. This culminated in the commissioning in 1970 of iron and steelmaking facilities to produce billets for domestic and export markets. Expansion continued with the commissioning of a pipe plant in 1972 and a prepainting line in 1982. Total output at this time averaged 300 000 tonnes a year.
In the 'Think Big' era of New Zealand industrialisation, the mill was upgraded. In 1987 New Zealand Steel was acquired by Equiticorp. However, Equiticorp was bankrupted in the New Zealand sharemarket crash of 1987. In 1989 New Zealand Steel was acquired by Helenus Corporation, which comprises Fisher & Paykel, Steel & Tube, ANZ and BHP. In 1992 BHP took up a controlling interest with an 81% shareholding by acquiring the shares of Fisher & Paykel and Steel & Tube. The company was initially renamed BHP New Zealand Steel Limited, but in 2002 it was renamed New Zealand Steel when BHP Steel was listed on Australian stockmarket under the name Bluescope Steel[3].
[edit] The ore
The ironsand ore is mined at an opencast mine at Waikato North Head[1]. The ironsand is then mixed to form a slurry and transported to the mill by a 21 kilometre long pipeline[2]. Approximately, 1.2 million tonnes of ironsand ore are delivered to the mill annually.
[edit] The processes
Glenbrook's iron plant contains four multiple hearth furnaces (MHFs)[4], four rotary kilns, and two melters. The rotary kilns reduce the ore to metallic iron. This process is unusual as most mills use blast furnaces for this reduction process.
In the steel making plant vanadium recovery and removal is done due to the high vanadium content of the ironsand ore[2]. Oxidation of the molten metal and contaminates is achieved by blasting oxygen into and on top of the molten metal by a klockner oxygen blown maxhutte (KOBM). This klockner oxygen blown maxhutte is the second unusal piece of equipment the mill operates.
[edit] References
- ^ a b c "Glenbrook Steel Site Operations". 2011. http://www.nzsteel.co.nz/about-new-zealand-steel/operations-/glenbrook-steel-site. Retrieved 2012-02-21.
- ^ a b c d e John Green and Jeremy Batchelor (2008). The Manufacture Of Steel. http://nzic.org.nz/ChemProcesses/metals/index.html.
- ^ a b "New Zealand Steel - History". 2011. http://www.nzsteel.co.nz/about-new-zealand-steel/history. Retrieved 2012-02-20.
- ^ New Zealand Steel (2012). "The science of steel". http://www.nzsteel.co.nz/about-new-zealand-steel/student-information-/the-science-of-steel. Retrieved 2012-02-25.
