Mining in New Zealand

Mining in New Zealand began when the Māori quarried rock such as argillite in times prior to European colonisation.[1] Mining by Europeans began in the latter half of the 19th century.

New Zealand has abundant resources of coal, silver, iron ore, limestone and gold. It ranked 22 in the world in terms of iron ore production and 29th in gold production. The total value of mineral production in New Zealand was $1.5 billion in 2006 (excluding oil and gas). The most important metallic minerals produced are gold (10.62 tonnes), silver (27.2 tonnes) and titanomagnetite ironsand (2.15 million tonnes). A 2008 report estimated that the unexploited resources of just seven core minerals (including gold, copper, iron and molybdenum) totalled around $140 billion in worth.[2]

The mining sector makes a significant contribution to the New Zealand economy. In 2004 the value of production from mining (excluding oil and gas) was $1,142 million, or just under 1% of gross domestic product.[3] In 2017 mining contributed $3,079m (1.3%) to a GDP of $235,945m.[4]

In 2009 there were 6,800 people employed directly in mining, and 8,000 people, indirectly, flowing from the economic activity of the 6,800. The median wage for a mining employee was $57,320 in 2008, compared to the New Zealand median of $33,530. In 2017 mining employed 5,300 (0.2%), out of a total workforce of 2,593,000.[5] In 2015 miners' earnings average hourly earnings were $39.86 and median hourly earnings $31.33, though the number of miners had fallen to 6,300, compared to nationwide figures of $27.49, $22.92 and 2,004,100 (3%).[6] These figures may though need to be treated with caution, as miners appear to have been earning 5% of total income (average earnings x employees), though GDP contribution in 2015 was only 1.6%.[4]

The latter decades of the 20th century and into the 21st century saw opposition to mining on environmental grounds. The Crown Minerals Act 1991 is a major piece of legislation relating to mining, and a review of Schedule 4 of the Act provoked considerable controversy late in the first decade of the 2000s.

Gold mining in Otago

History

Iron made from Taranaki ironsand was displayed at The Great Exhibition, London in 1851.[7]

In 1865, the Alpha well was drilled near Mikotahi at New Plymouth.[8] This was the first oil well in what is now the Commonwealth and one of the first in the world. A petroleum industry developed at Moturoa, including producing wells and refineries. The last refinery there was closed in 1972.

Resources

Coal
New Zealand Coal Production, 1878 - 2014.[9]

Coal mining produced almost 4 million tonnes of coal in 2014, of which 44% was exported.[9] In 2016 it was down to 2,834,956 tonnes.[10] New Zealand coal reserves are in excess of 15 billion tonnes, mainly in Waikato, Taranaki, West Coast, Otago and Southland.[9] Over 80% of the reserves are in Southland lignite deposits worth $100 billion.[2] Coal is produced from four underground and 21 opencast mines.[11] The largest coal mining company was Solid Energy, a state-owned enterprise.

Gold
Gold rush tents and digs in Gabriel Gully, Clutha District, Otago, 1862.

Prospectors discovered gold in the Coromandel Peninsula in 1852, sparking the Coromandel Gold Rush, the Otago Gold Rush and the West Coast Gold Rush in the 1860s. Initially alluvial gold was recovered, but then mining for gold in quartz veins which was recovered using stamper batteries took over. From the 1890s Otago rivers were dredged for gold, using New Zealand-developed floating dredges.[12]

Mining for gold has a long history in areas like the Coromandel Peninsula.

Up to 2003 an estimated 998.71 tonnes of gold had been mined in New Zealand, a little under one percent all the gold mined worldwide. Available figures suggest that to that time a minimum of 312 tonnes had come from the Coromandel Peninsula, 274 tonnes from the West Coast, and 265 tonnes from Otago. Production peaked in 1866 at some 22.9 tonnes.[13] Gold worth $250M in 2006 was produced from two large hard-rock mines (Martha Mine and Macraes Mine), several medium-sized alluvial operations, and a large number of small alluvial mines.

Ironsands

The Waikato North Head ironsand mine produces up to 1.2 million tonnes of ironsand a year, for use in the New Zealand Steel mill at Glenbrook. The deposit is estimated to contain more than 150 million tonnes in total.[14] Rather more is produced at Tahāroa, all of which is exported.[15]

Environmental issues

Environmental issues with mining include acid mine drainage and large scale modifications to landscapes. Acid mine drainage from coal mining is a serious problem in New Zealand. It is estimated to adversely affect 125 kilometres of streams mainly in the Buller District of the West Coast Region of the South Island. There has been very little remediation of acid mine drainage. Regulation of AMD has been vague and enforcement is lacking. AMD from mines that were established before the Resource Management Act 1991 has been allowed to continue.[16]

The Tui mine in the Kaimai Range which closed in 1973 is considered one of the worst toxic waste sites in New Zealand and the government has allocated almost $10 million for cleaning up the site. Structural failure of historic underground mine workings have led to subsidence, cracking and collapse on properties in Waihi, a township that has built up around the current open pit. The Stockton Mine on the West Coast of the South Island, has historically been responsible for acid mine drainage in adjoining waterways,[17] and has since built a comprehensive water treatment plant on the Stockton plateau.[18] Stockton poses a threat to some native species, although has carried out significant biodiversity conservation work in the region, and mountaintop removal mining has happened on the site in recent years. Over a one hundred-year period Mount Smart in Auckland was mined to such an extent that it is now level with the surrounding land. Several other Auckland volcanoes have suffered a similar fate.

In 2011 arsenic laden soil was discovered in the suburb of Moanataiari in Thames. The area had been reclaimed from the Firth of Thames using mine tailings, mine waste and rubble. Funding from the government was given towards the cost of soil testing.[19]

New frontiers

Carbon Capture and Storage (CCS) is attracting funding in the billions of dollars as part of global efforts to address greenhouse gas emissions.[20] CCS may well have a vital role to play in the portfolio of technologies to be deployed. The New Zealand Government is a partner with the Australian Government in the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) for research to support commercial-scale CCS.[21] However, in the New Zealand context, University of Canterbury researchers authored a 2009 paper on CCS published in the peer-reviewed journal Energy Policy. The paper considered the permanence of CO2 storage was uncertain and that CCS was unlikely to significantly reduce carbon emissions. The paper concluded that further investment in CCS was seriously questionable as a policy.[22]

Coal Seam Gas (CSG) is a form of natural gas occurring naturally in deep coal seams that could potentially add to New Zealand's gas supply.[23] In 2008, Solid Energy trialled CSG extraction at the Waikato coal fields, for use in electricity generation.[24]

Deep-sea metallic mineral deposits in the Kermadec volcanic arc are attracting research into how they are formed and how they influence the surrounding undersea biodiversity.[25] Mineral-rich fluids coming out of seafloor hot springs contact cold sea water and precipitate out high-grade ore deposits containing gold, copper, lead, zinc, iron, manganese and other metals. In one sense, these are renewable resources because they are constantly being formed. Discovering these deposits is one matter; mining them in an economic and environmentally appropriate way is another. Extraction of these resources is viewed as a long-term prospect. A proposal for the protection of part of the Kermadec volcanoes is being developed by the Pew Environmental Group.[26]

Geothermal energy is experiencing a renaissance in New Zealand. This renewable source of energy could contribute to 20% of New Zealand's electricity needs after the next decade.[27] Current research led by the GNS Science and the University of Auckland is tipped to enable cheaper geothermal energy, and identify new systems in the Central North Island for development.

Ironsands offshore of New Zealand from Northland south to Whanganui, and off the South Island's West Coast is estimated to hold some billions of tonnes of titanomagnetite resource.[28] Titanium and vanadium are the main by-products. The resource is in the stage of being prospected and explored, and assessed for its economic potential.

Low-temperature geothermal energy can be used potentially for space heating, hot pools, heat pumps in the home, heating greenhouses and aquaculture. The heat may be sourced from hot spring systems, disused petroleum wells, heated waters in flooded underground coal and mineral mines, heat in underground aquifers, and heat in rocks. Research in this field in New Zealand is led by GNS Science.[29]

Methane hydrates (fire ice) are a crystalline form of methane trapped in water, occurring in deep-water continental shelf sediments in many parts of the world, including New Zealand.[30] This resource may furnish a future source of natural gas. Work is underway in New Zealand to determine economically viable deposits, and technologies for safe extraction.[31] In New Zealand, methane hydrates are found in shallower waters than elsewhere in the world.

Underground coal gasification (UCG) is a way of accessing energy from coal deposits that lie too deep underground or are too dangerous to be mined or are otherwise uneconomic. Air, oxygen or steam is injected at high temperatures, to burn the coal underground. Separate wells are drilled to capture the resulting "coal gas" which is in essence a form of natural gas. When combined with CCS, this offers a low-emissions route to generating electricity from coal.[32]

Opposition
A burning coal mine near Denniston

The Coromandel Watchdog lobby group has been active in lobbying against gold mining on the Coromandel Peninsula since the 1970s. It has recently begun to work against proposals to restart mining in some areas of the Coromandel Peninsula which have been off-limits to mining for a long time, and has argued that any claim of "surgical" mining operations being possible is farcical, when one realises that even for such mining, roads would have to be built into the areas, ore processing plants constructed, as well as tailings and chemical byproducts of the ore separation process disposed of.[2]

Sand mining from both beaches and the seabed has encountered opposition. Kiwis Against Seabed Mining,[33] an environmental lobby group, formed when plans were revealed for the mining of the seabed off the West Coast of the North Island.

There are numerous coal mines on the West Coast of the South Island. The Cypress Mine, planned for the Westport area, is opposed by the Save Happy Valley Coalition due to effects on landscape values, biodiversity and climate change.

A speech by the Minister for Economic Development Gerry Brownlee to the Australasian Institute of Mining and Metallurgy in August 2009[34] provoked a reaction from environmental groups. In the speech Brownlee announced a review of Schedule 4 of the Crown Minerals Act. The Schedule lists conservation land such as national parks and reserves as off-limits to mining.

Advocacy for the NZ resource sector

In 2008 a number of mainly gold and coal producing companies in New Zealand set up Straterra, an incorporated society, to provide a collective voice for the NZ resource sector.[35] Staterra's members and affiliates represent 88% of the value of NZ production of all minerals, except oil & gas and geothermal resources. Straterra also works closely with the petroleum sector and has links to the geothermal sector. Straterra participates in government policy processes, carries out government and industry relations, and provides advocacy for the NZ resource sector including via the media.

A key focus for the NZ resource sector is to promote mature, well-informed debate on mineral and energy issues.[36] Straterra believes that properly managed and encouraged the NZ resource sector can make a significant contribution to the New Zealand economy, and can be managed in environmentally responsible ways, with the passing of the Resource Management Act and the Crown Minerals Act in 1991.

Accidents

In earlier years, coal mining had a high rate of injuries and death, most of them individual deaths. Between just 1900 and 1914 there were 141 men killed, of which 98 were individual deaths.[37]

The largest-scale accidents are:

  • 21 February 1879, Kaitangata coal mine disaster, 34 miners died when candles caused an underground explosion
  • 26 March 1896, Brunner coal mine disaster, 65 miners killed by an explosion or by poisonous gases following the explosion. As of 2020 this is New Zealand's largest death toll from an industrial accident.
  • 12 September 1914, Ralph Mine, Huntly, a naked light caused an explosion that killed 43 coal miners[38]
  • 3 December 1926, Dobson coal mine, nine killed due to an explosion
  • 24 September 1939, Glen Afton coal mine, Huntly, 11 asphyxiated by carbon monoxide
  • 19 January 1967, Strongman coal mine, 19 miners killed by explosion[39]
  • 19 November 2010, Pike River mine accident, 29 dead

Mining towns

Current

Historic

See also

References
  1. "Argillite quarry". Te Ara - the Encyclopedia of New Zealand. Retrieved 20 November 2010.
  2. Cumming, Geoff (6 March 2010). "Miners press to enter the green zone". The New Zealand Herald. Retrieved 24 March 2010.
  3. Nathan, Simon (2 March 2009). "Mining and underground resources - the mining industry". Te Ara - the Encyclopedia of New Zealand. Retrieved 30 May 2012.
  4. "Gross domestic product: September 2017 quarter – tables". StatsNZ.
  5. "Household Labour Force Survey: September 2017 quarter – tables". StatsNZ.
  6. "New Zealand Income Survey: June 2015 quarter – tables". StatsNZ.
  7. "Obituary Mr F A Carrington". Taranaki Herald. 15 July 1901. p. 2.
  8. Lambert, Ron (1995). In Crude State - a History of the Moturoa Oilfield New Plymouth. Methanex New Zealand. ISBN 0-473-03428-X.
  9. "Energy in New Zealand". MBIE. August 2015. Archived from the original on 15 February 2016. Retrieved 23 August 2015.
  10. Minerals, New Zealand Petroleum and. "Operating coal mine production figures". New Zealand Petroleum and Minerals. Retrieved 5 February 2018.
  11. "Coal Overview". Crown Minerals, Ministry of Economic Development. 17 December 2008.
  12. Dredging for Gold from Te Ara, Encyclopaedia of New Zealand
  13. "NZ Gold History Archived 5 February 2014 at Archive.today," New Zealand Gold Merchants Ltd., retrieved 5 February 2014.
  14. "Waikato North Head Mine Site". New Zealand Steel. Retrieved 1 February 2016.
  15. "Huge ironsands expansion - Quarrying & Mining Magazine". Quarrying & Mining Magazine. 11 November 2014. Archived from the original on 19 February 2018. Retrieved 1 February 2018.
  16. Trumm, D (2007). "Acid mine drainage in New Zealand" (PDF). Reclamation Matters. American Society of Mining and Reclamation (ASMR). 3 (1). Retrieved 9 September 2011.
  17. "Stockton revisited: The mine and regulatory minefield" (PDF). Parliamentary Commissioner for the Environment. October 2009. Archived from the original (PDF) on 24 July 2011. Retrieved 25 January 2010.
  18. Straterra Inc (October 2010). "The greening of Stockton". Archived from the original on 24 July 2011. Retrieved 1 February 2011.
  19. "Govt to support further testing at Moanataiari". Beehive -New Zealand Government. 30 November 2011. Retrieved 30 November 2011.
  20. International Energy Agency (2016). "20 Years of Carbon capture and Storage" (PDF). Retrieved 15 June 2016.
  21. "About CO2CRC". The Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC). 2012. Retrieved 13 March 2012.
  22. S.C. Page; A.G. Williamson; I.G. Mason (September 2009). "Carbon capture and storage: Fundamental thermodynamics and current technology". Energy Policy. 37 (9): 3314–3324. doi:10.1016/j.enpol.2008.10.028. ISSN 0301-4215.
  23. Business Desk (22 September 2010). "Coal seam gas the next great energy source". Retrieved 2 February 2011.
  24. Solid Energy New Zealand. "Coal seam gas in NZ" (PDF). Archived from the original on 22 May 2010. Retrieved 27 January 2016.
  25. Various authors, symposium convened by the Pew Environmental Group. "Kermadecs symposium abstracts". Retrieved 2 February 2011.
  26. Pew Charitable Trusts. "Global ocean legacy". Archived from the original on 10 September 2012. Retrieved 2 February 2011.
  27. Ed Mrocek, GNS Science. "Geothermal: New Zealand's energy solution". Retrieved 2 February 2011.
  28. Trans-Tasman Resources and Lindsay Clark, Crown Minerals Group (8 July 2010). "Major iron ore resource discovered in TTR offshore ironsands project". Retrieved 2 February 2011.
  29. Brian Carey; GNS Science. "Low-enthalpy geothermal resources". Retrieved 2 February 2011.
  30. GNS Science (10 May 2010). "7th International Workshop on Methane Hydrate R&D". Retrieved 2 February 2011.
  31. Smellie, Pattrick (20 September 2010). "Crown Minerals chases deep-sea hydrates". Business Desk. Scoop. Retrieved 2 February 2011.
  32. Carbon Capture Journal (6 September 2010). "Research partnership for UCG with CCS". Archived from the original on 8 July 2011. Retrieved 2 February 2011.
  33. "Mission Statement". Kiwis Against Seabed Mining. Retrieved 29 November 2010.
  34. "Opening Address to Australasian Institute of Mining and Metallurgy 2009". New Zealand Government. 26 August 2009. Retrieved 28 August 2009.
  35. Straterra Inc (July 2010). "About Straterra". Archived from the original on 24 February 2011. Retrieved 1 February 2011.
  36. Straterra Inc (November 2010). "NZ mining". Explanation of mining in New Zealand. Archived from the original on 24 February 2011. Retrieved 1 February 2011.
  37. Alan Sherwood & Jock Phillips (2 March 2009). "Coal and coal mining: Mining accidents". Te Ara - the Encyclopedia of New Zealand. Retrieved 20 November 2010.
  38. "Mining: Ralph's Mine". Christchurch City Libraries. Retrieved 20 November 2010.
  39. "Strongman Mine explosion". Christchurch City Libraries. Retrieved 20 November 2010.

Further reading
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