Zinc mining

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Zinkgruvan, a zinc mine in Askersund Municipality, Sweden Zinkgruvan zink mine Sweden 001.JPG
Zinkgruvan, a zinc mine in Askersund Municipality, Sweden

Zinc mining is the process by which mineral forms of the metal zinc are extracted from the earth through mining. A zinc mine is a mine that produces zinc minerals in ore as its primary product. Common co-products in zinc ores include minerals of lead and silver. Other mines may produce zinc minerals as a by-product of the production of ores containing more valuable minerals or metals, such as gold, silver or copper. [1] Mined ore is processed, usually on site, to produce one or more metal-rich concentrates, then transported to a zinc smelter for production of zinc metal. [2]

Contents

Global zinc mine production in 2020 was estimated to be 12 million tonnes. The largest producers were China (35%), Australia (12%), Peru (10%), India (6.0%), United States (5.6%) and Mexico (5.0%), with Australia having the largest reserves. [3]

The world's largest zinc mine is the Red Dog open-pit zinc-lead-silver mine in Alaska, with 4.2% of world production. [4] [5] Major zinc mine operators include Vedanta Resources, Glencore, BHP, Teck Resources, Sumitomo, Nexa Resources, Boliden AB, and China Minmetals. [5]

History

Zinc deposits have been exploited for thousands of years, with the oldest zinc mine, located in Rajasthan, India established nearly 2000 years BP. [6]

Pure zinc production occurred in the 9th century AD while, earlier in antiquity zinc was primarily utilized in the alloying of copper to produce brass. [7] This is because the isolation of zinc metal from its ore poses a unique challenge. At the temperature zinc is released from its ore it also vaporizes into a gas, and if the furnace is not airtight, the gaseous zinc reacts with the air to form zinc oxide. [8] [9]

Metallic zinc smelting occurred in 9th century BC in India, followed soon by China 300 years later, and In Europe by 1738 AD. [7] The methods of smelting in China and India were most likely independently developed, while the method of smelting developed in Europe was likely derived by the Indian method. [10] [7]

The primary modern use for zinc is for coating iron and steel in order to prevent its corrosion, with nearly half of worldwide zinc production going towards that purpose. [11] Approximately 20% of the world's zinc is used in the production of brass, where zinc is alloyed with copper in between ratios of 20-40% zinc. [11] Of the remaining 30% of the global production of zinc, half is used in the production of zinc alloys, where zinc is combined with varying amounts of aluminium, and magnesium. [11] The remaining zinc is used in various other industries from agriculture as a fertilizer and human consumption as a supplement. [11]

Methods of extraction

Schematic cut and fill mining Method overview.png
Schematic cut and fill mining

Zinc is mined both at the surface and at depth. Surface mining of zinc, typically used for oxide ores, while underground mining yields zinc sulfide ores. [12] Some of the common methods of zinc mining are open pit mining, open stope, and cut and fill mining: [12] [8] [13] [14]

Open-pit mining : Surface mining involves the removal of waste rock from above an ore deposit before it can be extracted. Once the waste overburden is removed, ore and waste are then mined in parallel, primarily using track-mounted excavators and rubber-tired trucks. In smaller scale operations, front loaders may be used. [15]

Open Stope mining: This is a method of underground mining where ore bodies are completely removed leaving sizeable caverns (stopes) within the mine. Open stope mining leaves these caverns with no additional bracing or external support, instead the cavern walls are supported by random pillars of ore which have not been removed. [15]

Cut and Fill stoping: A method of underground mining which removes ore from below the deposit. The stope is then filled with waste rock to replace the mined out ore to support the stope walls, and to provide an elevated floor for the miners and equipment to further extract ore from the deposit. [15]

Production

Global mine production of zinc in 2019 was 12.9 million tonnes, a 0.9% increase from 2018, with the increase primarily attributed to increased output from zinc mines located in Australia and South Africa. [16] [3]

In 2020, production of zinc is expected to rise 3.7% to 13.99 million tonnes, with the increase due to increased production of zinc by China and India. [17]

In 2019 global demand for refined zinc exceeded supply and resulted in a deficit of 0.178 million tonnes, while in 2020 there is an expected surplus of 0.192 million tonnes. [17]

Major zinc producing countries ranked by their output for 2019 are as follows: [3]

CountryOutput (million tonnes)Share of world production
China4.37134%
Peru1.40411%
Australia1.28310%
USA0.7956.1%
India0.7125.5%
Mexico0.7035.4%
Bolivia0.463.5%
Canada0.3392.6%
Other Countries2.8322%

Environmental impact

Research conducted in the health of the benthic macroinvertebrate populations in the mining areas of southeastern Missouri, a US state, have yielded a wealth of information on the effect of zinc mining and its effect on its local environment. Fish and Crayfish populations in localities near mining sites have been observed to be much lower than other populations found in reference sites; with the crayfish possessing metal concentrations within their tissues at a much greater concentration than their reference counterparts. [18] Other investigation into the effect of the health of mussel populations that reside near lead-zinc mining areas have found that the populations residing near mining areas possessed reduced biomass, and were less specious than those found in their reference sites. [19] Plant tissue have been reported to possess concentrations of metals 10-60% higher than reference. [20] Macroinvertebrate assessments of localities immediately downstream of mining activity have observed a reduction in biotic condition 10-58% and with the ecosystem having an impaired ability to support its populations when compared to other reference sites. [21]

Benthic macro-invertebrates such as crayfish and mussels represent a pathway for biomagnification, where the concentration of noxious materials within organisms at higher trophic levels accumulates as a result of consuming contaminated prey. In addition, benthic macroinvertebrate populations are frequently used as indicators of overall ecosystem health. [18] [22] [23]

Assessment of soil samples from agricultural areas near a lead-zinc mining region in Guangxi, China have observed a "Serious pollution level" of zinc in the soils of the paddy fields relatively close to the mining area and a "Moderate pollution level" in the aerated fields relatively further away. [24] The research also indicated that as a result of their Nemerow synthetic index assessment, the region under study is not fit for agricultural purposes. [24] Other investigation into the effect of zinc mining on agricultural soils in the Heilongjiang Province of China has found that the soils were "moderately contaminated" and a significant reduction in the population and diversity of the bacterial assemblages within the soils and reduced activity of soil enzymes. [25] The activity of the bacteria and enzymes aid plant matter in the uptake of nutrients, decompose decaying matter, and other ecosystem interactions. [25] Their reduction and impaired effectiveness result in poorer agricultural productivity.

Zinc mines

The world's ten largest zinc producing mines (by tonnes of zinc) are:

Name of the mineOwnerProduction
tonnes		Operations
Red Dog (USA) Teck Resources 552,400
(2019) [4] 		open-pit zinc-lead-silver mine
Rampura Agucha (India) Vedanta Resources (64.9%)
Government of India (29.5%)		357,571
(2019) [26] 		underground zinc-lead-silver mine
Mount Isa (Australia) Glencore 326,400
(2019) [27] 		George Fisher and Lady Loretta underground lead-zinc-silver mines
Antamina (Peru) BHP (33.75%), Glencore (33.75%), Teck
Resources (22.5%), Mitsubishi Corporation (10%)		303,555
(2019) [4] 		open-pit copper-zinc-molybdenum mine
McArthur River (Australia)Glencore271,200
(2019) [27] 		open-pit zinc-lead-silver mine
San Cristóbal (Bolivia) Sumitomo Corporation 206,100
(2019) [28] 		open-pit silver-lead-zinc mine
Dugald River (Australia) China Minmetals 170,057
(2019) [29] 		underground cut and fill stoping
Vazante (Brazil) Nexa Resources 139,000
(2019) [30] 		underground and open pit zinc-lead-silver mine
Cerro Lindo (Peru)Nexa Resources126,000
(2019) [30] 		underground zinc-lead-copper-silver mine
Tara (Ireland) Boliden AB 122,463
(2019) [31] 		underground zinc-lead mine

See also

Related Research Articles

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<span class="mw-page-title-main">Underground hard-rock mining</span> Mining techniques used to excavate hard minerals and gems

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<span class="mw-page-title-main">Copper extraction</span> Process of extracting copper from the ground

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<span class="mw-page-title-main">Kidd Mine</span> Kidd Township, Timmins area, Ontario

Kidd Mine or Kidd Creek Mine is an underground base metal (copper-zinc-silver) mine 24 km (15 mi) north of Timmins, Ontario, Canada. It is owned and operated by Swiss multinational Glencore Inc. The mine was discovered in 1963 by Texas Gulf Sulfur Company. In 1981, it was sold to Canada Development Corporation, then sold in 1986 to Falconbridge Ltd., which in 2006 was acquired by Xstrata, which in turn merged with Glencore in 2013. Ore from the Kidd Mine is processed into concentrate at the Kidd Metallurgical Site, located 27 km (17 mi) southeast of the mine, which until 2010 also smelted the ore and refined the metal produced. Following the closure of the majority of the Met Site, concentrate is now shipped to Quebec for processing. Kidd Mine is the world's deepest copper-zinc mine.

<span class="mw-page-title-main">Silver mining</span> Extraction silver from the ground

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<span class="mw-page-title-main">McArthur River zinc mine</span> Mine in Northern Territory, Australia

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<span class="mw-page-title-main">Tara Mine</span> Zinc and lead mine in Ireland

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<span class="mw-page-title-main">Environmental effects of mining</span> Environmental problems from uncontrolled mining

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<span class="mw-page-title-main">Lead smelting</span> Process of refining lead metal

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Mining in North Korea is important to the country's economy. North Korea is naturally abundant in metals such as magnesite, zinc, tungsten, and iron; with magnesite resources of 6 billion tonnes, particularly in the North and South Hamgyong Province and Chagang Province. However, often these cannot be mined due to the acute shortage of electricity in the country, as well as the lack of proper tools to mine these materials and an antiquated industrial base. Coal, iron ore, limestone, and magnesite deposits are larger than other mineral commodities. Mining joint ventures with other countries include China, Canada, Egypt, and South Korea.

<span class="mw-page-title-main">Zinc mining in the United States</span>

Zinc mining in the United States produced 780,000 tonnes of zinc in 2019, making it the world's fourth-largest zinc producer, after China, Australia, and Peru. Most US zinc came from the Red Dog mine in Alaska. The industry employed about 2,500 in mining and milling, and 250 in smelting.

References

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