The Fimiston Open Pit, colloquially known as the Super Pit, is an open-pit mine in Australia. It was Australia's largest open cut gold mine until 2016, when it was surpassed by the Newmont Boddington gold mine, also in Western Australia. The Super Pit is located off the Goldfields Highway on the south-east edge of Kalgoorlie, Western Australia. The pit is oblong in plan view and is approximately 3.5 kilometres long, 1.5 kilometres wide and over 600 metres deep.[1][2]

Super Pit
Fimiston Open Pit gold mine, c. 2005
Location
Super Pit is located in Western Australia
Super Pit
Super Pit
Location in Western Australia
LocationKalgoorlie
StateWestern Australia
CountryAustralia
Coordinates30°46′29″S 121°30′34″E / 30.77472°S 121.50944°E / -30.77472; 121.50944
Production
ProductsGold
Production432,001 troy ounces (13.4367 t)
Financial year2022–23
History
Opened1893
Owner
CompanyNorthern Star Resources
Websitesuperpit.com.au
Year of acquisition2020 (2020)
Map
Fimiston Open Pit (Super Pit) gold mine panorama, 2019 Aug

The Fimiston Open Pit is owned by Northern Star Resources. The mine produced 456,000 troy ounces (14.2 t) of gold in 2019, and employs around 1,100 employees and contractors directly on site.[3]

Earlier stages

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The open pit area exists in what had been known as the 'Golden Mile' which consisted of a large number of historical mining leases and underground mines, included:

Paringa
Oroya
Brown Hill
Chaffers
Hainault

Consolidation into a single open pit mine was first attempted by Alan Bond, but he was unable to complete the task.

The Fimiston Open Pit was eventually created in 1989 by Kalgoorlie Consolidated Gold Mines, a 50:50 corporate joint venture between Homestake Gold of Australia and Gold Mines of Kalgoorlie (a Normandy Mining subsidiary).[4][5] Barrick Gold acquired its share of the mine in December 2001, when it took over Homestake Mining Company. Newmont became part-owner of the mine three months later, when it acquired Normandy Mining in February 2002.[6][7] Saracen Mineral Holdings Limited acquired its share of the mine on 28 November 2019, when it purchased Barrick Gold's 50% stake.[8] Northern Star Resources acquired its share of the mine on 3 January 2020, when it purchased Newmont's 50% stake.[3][9][10]

Geology

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Most of the gold mined in the Fimiston Open Pit occurs within ore lodes formed by ancient shears in a rock unit called the Golden Mile Dolerite. The gold mining area of Kalgoorlie-Boulder-Fimiston has long been called the Golden Mile because of the geographical concentration of rich mines in that area, even though the lodes occur in an area over 2 km in length and 1 km in depth.

Production

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Mining is via conventional drill and blast mining via face shovels and dump trucks. Around 15 million tonnes of rock are moved in any given year, consisting primarily of waste rock.

Gold within the Golden Mile lode system is unusual in that it is present as telluride minerals within pyrite. In order to recover the gold, the ore must be crushed, passed through a gravity circuit to recover the free gold present in some of the higher-grade lodes, and then subjected to flotation to produce an auriferous pyrite-telluride concentrate. The concentrate is then treated at an IsaMill Ultra Fine Grinding (UFG) mill at Fimiston and then cyanidised, or trucked to the Gidji Processing Plant, 20 kilometres north of Kalgoorlie. At Gidji, the concentrate is treated in ultrafine grinding (UFG) mills, and then subjected to cyanide extraction of gold.[11]

Prior to the installation of the UFG mills, concentrate was treated at Gidji in two circulating fluid bed roasters. Roasting ceased in 2015.[11]

 
Gold mines in the Kalgoorlie region

Figures

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Past production figures were:[12][13][14][15]

Year Production Grade Cost per ounce
1998-99[16] 718,554 ounces 2.37 g/t US$236
2000 715,164 ounces 2.27 g/t A$325
2001 616,344 ounces 2.14 g/t A$397
2002 720,050 ounces 1.73 g/t A$222
2003
2004
2005
2006
2007 628,000 ounces 1.53 g/t
2008 612,000 ounces 1.56 g/t
2009 690,000 ounces US$609
2010 815,000 ounces
2011 815,000 ounces
2012 660,000 ounces
2013 660,000 ounces
2014 670,000 ounces
2015 645,000 ounces
2016 655,000 ounces
2017 700,000 ounces
2018 650,000 ounces
2019 450,000 ounces
2019–20
2020–21 472,089 ounces A$1,385
2021–22 486,001 ounces 1.4 g/t A$1,426
2022–23 432,001 ounces 1.3 g/t A$1,596

References

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  1. ^ "About us". KCGM. Kalgoorlie Consolidated Gold Mines. Archived from the original on 8 January 2020. Retrieved 10 April 2020.
  2. ^ Casey, J.P. (7 March 2019). "Super mines: Australia's biggest mining projects". Mining Technology. London. Retrieved 10 April 2020.
  3. ^ a b "2019 Annual Report and Form10-K" (PDF). Greenwood Village, Colorado: Newmont Corporation. 20 February 2020. p. 41. Retrieved 10 April 2020.
  4. ^ Treadgold, Tim. (1995) "History of the pit's development from 1989 to 1995", Australia's mining monthly, May 1995, pp. 31, 33-36.
  5. ^ Mulligan, David, ed. (1996). Environmental Management in the Australian Minerals and Energy Industries. Sydney: UNSW Press. p. 322. ISBN 978-0-86840-383-0. Retrieved 9 April 2019.
  6. ^ "In the matter of Normandy Mining Limited (No 3) [2001] ATP 30" (PDF). Takeovers Panel. Melbourne: Australian Takeovers Panel. 28 January 2002. Retrieved 17 March 2020.
  7. ^ MINEDEX website Archived 2008-09-11 at the Wayback Machine Golden Mile / KCGM search result, accessed: 26 January 2010
  8. ^ ASX Limited
  9. ^ "Annual Report 2019" (PDF). Toronto, ON: Barrick Gold Corporation. 25 March 2020. p. 57. Archived from the original (PDF) on 8 October 2021. Retrieved 10 April 2020.
  10. ^ ASX Limited
  11. ^ a b "Mineral Processing". The Super Pit. Kalgoorlie , WA: KCGM. 2019. Retrieved 9 April 2019.
  12. ^ The Australian Mines Handbook - 2003-04 Edition page: 127
  13. ^ "2021 Annual Report". www.nsrltd.com. Northern Star Resources. Retrieved 8 April 2022.
  14. ^ "2022 Annual Report". www.nsrltd.com. Northern Star Resources. Retrieved 1 March 2023.
  15. ^ "2023 Annual Report". www.nsrltd.com. Northern Star Resources. Retrieved 25 February 2023.
  16. ^ Normandy Mining Ltd - 1999 Mine-by-Mine Operating Results Archived 2003-08-29 at the Wayback Machine accessed: 14 February 2010

Bibliography

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  • Louthean, Ross (ed.). The Australian Mines Handbook: 2003-2004 Edition. Louthean Media Pty Ltd.
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