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Base metals react with acid or tarnish easily. Examples include copper, lead and zinc. Precious (or noble) metals are much more resistant to chemical attack and so do not tarnish. Examples include gold, silver and platinum.
New Zealand has a range of base and precious metals. A brief description of the occurrence and production of these metals in New Zealand and their properties and uses can be found below. For a detailed case study of gold and silver mining in New Zealand click here. Links to other relevant sections of this website and to other websites are provided. Links to other websites will open in a new window. To return to this website close the window.
…Aluminium
…Antimony
…Chromium
…Copper
…Gold
…Iron
…Lead & Zinc
…Manganese
…Mercury
…Molybdenum
…Nickel
…Platinum
…Silver
…Tin
…Titanium
…Tungsten
…Uranium
Occurrence
The third most common element in the earth’s crust, aluminium is mainly recovered from bauxite ore. Bauxite is not mined in New Zealand. A resource of some 20 million tonnes of low grade ore has been identified north of Kerikeri, but is regarded as not being economic in either the size of the deposit or the grade of ore.
Properties
Aluminium is light, strong and resistant to corrosion. It is a very good conductor of electricity and heat. Aluminium is an easy metal to work with.
Production
Over 300,000 tonnes of aluminium are smelted annually at Tiwai Point at Bluff. The bauxite is mined at Weipa in Queensland, processed into alumina, then shipped to Tiwai Point for smelting
Uses
Aluminium has a wide range of uses: soft drink cans, boats, ladders, tubing, cooking foil and much more. The electrical and communication industries make wide use of aluminium. Aluminium can be extruded, that is forced through a pattern to make aluminium shapes. Examples of extrusions include door and window frames and ladders. Aluminium has become a regular part of our everyday lives.
Links to other sites:
http://www.chemicalelements.com/elements/al.html
http://scifun.chem.wisc.edu/CHEMWEEK/Aluminum/ALUMINUM.html
Occurrence
Antimony is rarely found naturally as a native metal, usually occurring in combination with sulphur, copper, lead and silver. There are over 100 antimony minerals, the most common being stibnite. Stibnite has been recorded in many locations in New Zealand, and often occurs in epithermal quartz veins and in gold-bearing quartz lodes. It has been found in Westland, Otago, Marlborough, Northland, the Coromandel Peninsula and the Taupo Volcanic Zone.
Properties
Expands on solidifying, alloys with other minerals.
Production
There was some limited mining of stibnite deposits in the nineteenth century, mainly from quartz veins in the Marlborough area. Currently there is no antimony production in New Zealand and all our requirements are imported. It could be produced economically as a byproduct of gold mining in some areas in the future.
Uses
Used as an alloy with lead to harden it and increase its resistance to corrosion. As such, often used as an alloy with lead in car batteries. Compounds of antimony are also used in textiles, paints and plastics as a fire retardant.
Occurrence
The main chromium-bearing mineral is chromite. In New Zealand chromite occurs mainly in the South Island near Nelson and in West Otago.
Properties
Resistant to oxidation and high temperatures, alloys with other minerals
Production
New Zealand’s known chromite deposits are small. Some mining took place in the latter half of the nineteenth century in the South Island. Current needs are imported.
Uses
Chromite is alloyed with iron to produce steels, especially stainless steels, that have high strength and hardness, and a resistance to corrosion or breakdown at high temperature. It is also used to protect blast furnace linings and as an oxidising agent in the chemical industry.
Links to other sites
http://www.chemicalelements.com/elements/cr.html
Occurrence
There are four main types of copper deposits found in New Zealand, with significant occurrences on the Coromandel Peninsula and in the Nelson region.
Properties
A soft red metal which is a very good conductor of heat and electricity. Easily worked.
Production
Just over 8000 tonnes of copper has been mined in New Zealand since 1840 mainly from Kawau Island, but there is no current production and no known large economic copper deposit in the country. Copper requirements are imported. In 1998 a large uneconomic copper deposit was discovered north of Thames in the Coromandel Penninsula.
Uses
Widely used in the electronics and communications industries, in plumbing, and as an alloy in brass and bronze.
Links to other sites
http://www.chemicalelements.com/elements/cu.html
http://www.copper.org/
Occurrence
Gold occurs in the Hauraki Goldfield, the Coromandel Peninsula and in many parts of the South Island – mainly Nelson, Marlborough, Westland and Otago. Most of the gold in the North Island has come from hard rock deposits where gold occurs within rocks. South Island gold has come mainly from alluvial deposits where it is found as grains within river sand and gravel.
Properties
Gold is a soft yellow metal, valued for its ability to withstand corrosion, its chemical stability, high reflectivity and conductivity. It is ductile and malleable, this means it is easy to shape and stretch.
Production
New Zealand has a history of gold production in both the North and South Islands. Gold is produced from epithermal gold-silver-quartz veins at Martha Mine in the North Island. Alluvial gold is produced in many parts of the South Island, including Nelson, Marlborough, Westland and Otago. Macraes Mine in Otago is an open pit operation which commenced production in 1991. Most of the gold produced in New Zealand is exported.
Uses
Gold is used in industry, for jewelry, for investment, in coin and medallion manufacture, and in electronics, aerospace and medicine.
For a detailed case study on this website of gold production in New Zealand click here
Links to other sites
http://www.marthamine.co.nz
http://www.chemicalelements.com/elements/au.html
http://www.gold.org
http://www.goldinstitute.org/
Occurrence
In New Zeakand the main type of iron ore deposits are ironsands which are placer (or alluvial)n deposits derived from the erosion of andesitic and rhyolitic volcanic rocks. These ironsands occur in onshore dune and beach sands, and offshore marine sands along 480 km of coastline from Kaipara Harbour south to Wanganui.
Properties
A heavy, malleable, ductile, magnetic metal.
Production
The Waipipi mine near Wanganui produced 15.7 million tonnes of concentrate from 1971 to 1987. The total production was exported to Japan and Korea. Production from Waikato North Head and Taharoa has exceeded 40 million tonnes of concentrate. The ironsands at Taharoa are pumped offshore to ships for export. The ironsands at North Head are the raw material in steel production in the Glenbrook Mill operated by BHP New Zealand Steel Ltd. Steel products are for domestic use and export.
Uses
Iron is the most widely used of all metals, nearly always as an alloy. Iron is most commonly used to make steel and a variety of steel alloys. Galvanised steel, colour coated roofing, sheet steel, pipes and structural steel are all produced at Glenbrook. Overseas New Zealand ironsand concentrate is added to iron ore in small amounts to assist the steelmaking process and prolong the life of the linings of blast furnaces.
Iron continues to be the main metal used in our society and is used in transport, construction, machinery, and much more. Cars, bridges, trains, ships, concrete reinforcing and road rails and signs are all made from steel.
You can find out more about ironsand production at North Head in the Resources for Schools section Ironsands on this website.
Links to other sites
http://www.chemicalelements.com/elements/fe.html
Occurrence
In New Zealand most known lead deposits are in hydrothermal veins, commonly associated with gold and silver, such as the Hauraki goldfields. The only deposit actually mined for lead and zinc was the Tui Mine near Te Aroha. Lead and zinc usually occur together in ore deposits.
Properties
Lead is a heavy malleable metal which is easily shaped and resists corrosion. Zinc is the third most common nonferrous metal in the earth's crust (after aluminium and copper) and the second most common naturally occurring metal trace element in the human body. It is essential for good health and assists healing. Zinc reacts with iron, has a low melting point and is resistent to corrosion.
Production
The Tui Mine produced 163,000 tonnes of ore between 1967 and 1973. There is currently no production in New Zealand.
Uses
Lead is mainly used for storage batteries and solder. Until recently it was used as an additive in petrol. It is still used as flashing on the roofs of buildings. Zinc is used in precision die-casting, as a protective coating in galvanised iron and steel , and in copper-based alloys.
Links to other sites
http://www.chemicalelements.com/elements/pb.html
http://www.chemicalelements.com/elements/zn.html
http://www.zinc.org/
Occurrence
Manganese occurs in small deposits in the Bay of Islands, South Auckland and Otago. Maganese nodules exist on the floor of the Pacific Ocean below 1000m.
Properties
Manganese is an essential trace element and important for good health. It is a powerful oxidising agent and alloys readily with other metals.
Production
Small deposits have been worked in the past, notably around South Auckland and Otago. Current known reserves are uneconomic to mine.
Uses
Used mainly in ferromanganese alloys and as a scavenger to remove oxygen and sulphur in steel making. Essential in the making of dry cell batteries and also a component of a wide range of chemicals.
Links to other sites
http://www.chemicalelements.com/elements/mn.html
http://www.manganese.org
Occurrence
Mercury minerals are commonly deposited from relatively low temperature (less than 200 degrees C) hydrothermal fluids. In New Zealand the main mercury deposits are found in lake beds and extinct and active hot springs, particularly at Ngaiwha near Kaikohe in Northland.
Properties
A silver-coloured heavy liquid with a specific gravity of 13.6.
Production
Mercury was recovered at a variety of locations in the late nineteenth and early twentieth centuries, notably around the hot springs in Northland. Small resources still exist, but are currently uneconomic to develop.
Uses
Used in the manufacture of chlorine and caustic soda, pharmaceuticals, batteries, and many electronic devices. Until recently was used in dental fillings.
Links to other sites
http://www.chemicalelements.com/elements/hg.html
Occurrence
Occurs as molybdenite in Nelson and West Coast regions, small amounts have been found on the Coromandel Peninsula in association with gold-silver quartz veins.
Properties
Lead-grey to bluish in colour with a metallic lustre.
Production
Molybdenum has not been produced in New Zealand. Grades of known resources are currently uneconomic to develop.
Uses
Molybdenum is used mainly as an alloy to toughen steels. Minor amounts are also used in lubricants, dyes and catalysts.
Links to other sites
http://www.chemicalelements.com/elements/mo.html
Occurrence
The only known occurrence of economic significance is a nickel-copper sulphide deposit in Northwest Nelson. There is a minor and currently uneconomic deposit in Marlborough.
Properties
Nickel is a hard grey-white magnetic mineral. It is ductile, tough, strong and corrosion resistant.
Production
No nickel ore has been mined in New Zealand. Current needs are imported.
Uses
Nickel is mainly used in metal alloys, particularly stainless steel. It is also used in rechargeable batteries, coins, dyes and pigments, and as a catalyst.
Links to other sites
http://www.chemicalelements.com/elements/ni.html
Occurrence
Platinum group metals have been found in the Nelson area and also in Southland.
Properties
Platinum is a soft silvery-white metal, one of the six platinum group metals. It has catalytic properties, conducts electricity, and is resistant to heat and chemical attack.
Production
The only recorded production of platinum in New Zealand is as a byproduct of gold mining in the late nineteenth and early twentieth centuries at Orepuke in Southland. Some known deposits in the South Island are considered as possible economic deposits.
Uses
The main uses of platinum are in electronics and scientific apparatus, jewellery and dentistry. Platinum is used as a catalyst in petroleum refining and in car exhaust anti-pollution devices.
Links to other sites
http://www.chemicalelements.com/elements/pt.html
Occurrence
Silver minerals are found in New Zealand in association with gold, particularly in the Hauraki goldfield.
Properties
A soft, white, precious metal. Very similar properties to gold: ductile malleable, resists corrosion.
Production
Silver is produced from the Martha Mine in Waihi.
Uses
Silver is used in the photographic industry, electronics, and for jewellery and tableware.
For a detailed case study on this website of silver production in New Zealand click here
Links to other sites
http://www.marthamine.co.nz
http://www.chemicalelements.com/elements/ag.html
Occurrence
Usually associated with granite rocks. In New Zealand found only on the West Coast and Stewart Island.
Properties
Tin has a low melting point but high boiling point. It alloys easily, is non toxic, and does not corrode rapidly.
Production
About 1 tonne of alluvial tin concentrate was mined on Stewart Island late in the nineteenth century. There are currently no identified resources in New Zealand.
Uses
The largest use of tin is in tin-plating food cans. This use is decreasing as aluminium, tin-free steel and plastic are used instead. Tin is also used in alloys such as peweter, bronze and solder, in pesticides and fungicides and the manufacture of PVC plastic.
Links to other sites
http://www.chemicalelements.com/elements/sn.html
http://www.carnmetl.demon.co.uk/tin.htm
Occurrence
The main titanium minerals are ilmenite and rutile. They occur mainly in beach sands derived from the erosion of schist in the Southern Alps and volcanic rocks in the North Island.
Properties
Titanium metal is very strong and has a high resistance to heat. Titanium dioxide is used as a white pigment because of its high whiteness, opacity, and light-scattering properties.
Production
Available technology does not make the production of titanium from New Zealand resources economic. The resource is large, but often occurs with other minerals which would have to be separated. It is expected that further investigations and technological advances will make New Zealand’s titanium resources economic within the next few years.
Uses
Titanium dioxide is used as a white pigment in paints, plastics, rubber, paper and glass. Titanium metal is used in situations which require a light strong metal with a high resistance to heat and corrosion. It is widely used in aerospace construction and also in marine applications.
Links to other sites
http://www.chemicalelements.com/elements/ti.html
Occurrence
The main minerals in tungsten are scheelite and wolframite. These are found at various locations in the South Island, particularly Marlborough and Otago.
Properties
Tungsten has the highest melting point and lowest vapor pressure of all metals, and at temperatures over 1650°C has the highest tensile strength. It has excellent corrosion resistance and is attacked only slightly by most mineral acids.
Production
While about 4000 tonnes of tungsten was produced in the nineteenth and twentieth centuries, current depressed prices make any deposits in New Zealand uneconomic to mine.
Uses
Used mainly in the manufacture of tungsten-carbide abrasives and cutting tools, in steel alloys, and in electric light filaments.
Links to other sites
http://www.tungsten.com/mtstung.html
International Tungsten Industry Association http://www.itia.org.uk/
http://www.chemicalelements.com/elements/w.html
Occurrence
There are low grade uranium deposits on the West Coast of the South Island. Found in rocks and soil (about 2.7 parts per million) as well as in the oceans (about 1.3 parts per billion). Over 200 minerals contain uranium.
Properties
Common, but not found in nature as a free metal as it oxidises rapidly when exposed to air. The heaviest of the naturally occurring elements. Has a number of different forms (isotopes), of which three occur naturally.
Production
There is no record of any uranium production in New Zealand
Uses
Uranium is used in nuclear reactors which produce electricity from the heat released by nuclear fission reactions.
Links to other sites
http://www.chemicalelements.com/elements/u.html
http://www.uilondon.org/
http://www.uic.com.au/uran.htm
Information in this section has been summarised from two main sources: Minerals and Everyday Life by Richard Barker, Book 3 of the NZMIA Minerals Resource Series; and Mineral Wealth of New Zealand by Bruce Thompson, Bob Braithwaite and Tony Christie published by the Institute of Geological and Nuclear Sciences.
To order copies of the Mineral Resource Series click here. To request copies of our free brochures click here.
To find out more about the Institute of Geological and Nuclear Sciences click here or visit their website www.gns.cri.nz
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