Zinc mining 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 ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

produced 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 The Red Dog mine is a large zinc and lead mine in a remote region of Alaska, about north of Kotzebue, which is owned and operated by the Canadian mining company Teck Resources. It is located within the boundaries of the Red Dog Mine censu ...

in Alaska. The industry employed about 2,500 in mining and milling, and 250 in smelting.

Current zinc-mining districts

In 2019 zinc was mined in six States at 15 mines operated by five companies.

Red Dog Mine, Alaska

In 2019, 552,400 tonnes of zinc, 71 percent of US mined zinc production, and 4.2 percent of world zinc production, came from

Teck Resources Teck Resources Limited, known as Teck Cominco until late 2008, is a diversified natural resources company headquartered in Vancouver, British Columbia, that is engaged in mining and mineral development, including coal for the steelmaking indus ...

, the world's most productive zinc mine, in northwest

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

, near Kotzebue. The mine opened in 1989. The zinc is shipped as concentrate to foreign smelters. The Red Dog is a polymetallic deposit, which also produces lead and silver concentrates.

Admiralty Island, Alaska

Hecla Mining's

Greens Creek mine Greens may refer to: * Leaf vegetables such as collard greens, mustard greens, spring greens, winter greens, spinach, etc. Politics Supranational * Green politics * Green party, political parties adhering to Green politics * Global Greens * ...

located south-southwest of

Juneau, Alaska The City and Borough of Juneau, more commonly known simply as Juneau ( ; tli, Dzánti K'ihéeni ), is the capital city of the state of Alaska. Located in the Gastineau Channel and the Alaskan panhandle, it is a unified municipality A mu ...

, on

Admiralty Island Admiralty Island is an island in the Alexander Archipelago in Southeast Alaska, at . It is long and wide with an area of , making it the seventh-largest island in the United States and the 132nd largest island in the world. It is one of the ...

, opened in August 1989. The mine produces silver, gold, zinc and lead from a structurally and mineralogically complex

VMS deposit Volcanogenic massive sulfide ore deposits, also known as VMS ore deposits, are a type of metal sulfide Ore, ore deposit, mainly copper-zinc which are associated with and created by volcanic-associated hydrothermal events in submarine environments ...

. In 2019 it produced 56,805 tonnes of zinc in concentrate as a byproduct of silver-gold mining.

Coeur D'Alene district, Idaho

At the Coeur D'Alene mining district in northern Idaho, zinc is produced as a byproduct of silver mining in Hecla Mining's

Lucky Friday mine The Lucky Friday mine is an underground silver, lead, and zinc mine in the western United States, near Mullan, Idaho. Operated by Hecla Mining company, it is one of the few mines remaining operational in the Silver Valley of northern Idaho, produ ...

. In 2019 the mine produced 2,052 tonnes of zinc in concentrate.

Viburnum Trend, Missouri

Doe Run Resources' mines on carbonate-hosted lead-zinc deposits ( Mississippi Valley-type deposits) in the

Southeast Missouri Lead District The Southeast Missouri Lead District, commonly called the Lead Belt, is a lead mining district in the southeastern part of Missouri. Counties in the Lead Belt include Saint Francois, Crawford, Dent, Iron, Madison, Reynolds, and Washi ...

include Casteel, Buick, Brushy Creek, Fletcher, Sweetwater and Mine No. 29.

Middle and East Tennessee Zinc Complexes, Tennessee

In the Middle and East Tennessee Zinc Complexes, Nyrstar's six mines produce zinc from carbonate-hosted lead-zinc deposits. They are the Coy, Immel, and Young mines in the East Tennessee Zinc Complex, and the Gordonsville, Elmwood, and Cumberland mines in the Middle Tennessee Zinc Complex. Nyrstar produced 115,000 tonnes of zinc in concentrate from its East and Middle Tennessee mines in 2018.

Metaline district, Washington

In July 2019 Teck Resources' Pend Oreille mine in Washington's

Metaline Metaline is a town in Pend Oreille County, Washington, United States. The population was 173 at the 2010 census. History The Pend Oreille River was deepened at Box Canyon in 1906, allowing navigation to Metaline. The Metaline Mine then starte ...

mining district ceased production due to exhaustion of reserves.

Former zinc-mining districts

Tri-state district

The

Tri-State district The Tri-State district was a historic lead-zinc mining district located in present-day southwest Missouri, southeast Kansas and northeast Oklahoma. The district produced lead and zinc for over 100 years. Production began in the 1850s and 1860s i ...

of Missouri, Oklahoma and Kansas was the major zinc mining district in the United States, with production of 10.6 million tonnes of zinc from c.1850 through 1967. The Eagle-Picher mine of Cardin, Oklahoma, the largest and longest lived mine, ceased production in 1967.

Franklin mining district, New Jersey

The Franklin and Sterling Hill deposits with production of 6.3 million tonnes of zinc, account for 15 percent of all recorded zinc production in the contiguous United States. Major mining began about 1870, and the Sterling Hill mine was the last working underground mine in New Jersey when it closed in 1986.

Southeast Missouri lead district

Zinc was produced as a byproduct of lead mining in the

Austinville-Ivanhoe district, Virginia

Mining operations began in 1756 in the Austinville-Ivanhoe District of

Wythe County Wythe County is a county located in the southwestern part of the U.S. state of Virginia. As of the 2020 census, the population was 28,290. Its county seat is Wytheville. History Wythe County was formed from Montgomery County in 1790. It ...

, Virginia. By the time the mine closed in 1981, it was the most continuously mined

base metal A base metal is a common and inexpensive metal, as opposed to a precious metal such as gold or silver. In numismatics, coins often derived their value from the precious metal content; however, base metals have also been used in coins in the past ...

deposit in North America, with a total production of 1.4 million tonnes of zinc.

Smelting

The US has two smelter facilities, one primary and one secondary, producing commercial-grade zinc metal. Primary smelters produce metal from ore. The only US primary zinc smelter, the Nyrstar smelter at

Clarksville, Tennessee Clarksville is the county seat of Montgomery County, Tennessee, United States. It is the fifth-largest city in the state behind Nashville, Memphis, Knoxville, and Chattanooga. The city had a population of 166,722 as of the 2020 United States ...

, produced 120 tonnes of zinc, from a mix of ore from six mines in middle and east Tennessee, and recycled zinc products. Secondary zinc smelters produce zinc from recycled materials. A secondary zinc smelter in Pennsylvania closed in 2014, the operations being shifted to a new smelter in North Carolina using solvent extraction/electrowinning (SXEW). In addition, some non-smelting zinc recycling operations produced small amounts of zinc. The total amount of zinc produced from secondary operations was 70 tons. For primary and secondary smelters taken together, recycled products accounted for 25 percent (30,000 tonnes) of the refined zinc produced in US in 2019. Through 1940, the production of primary zinc by US smelters approximated the mined production of zinc ore. When zinc demand increased during World War II, US smelters turned to foreign zinc ore. US-smelted zinc reached a high of 926,000 tonnes in 1970, then dropped as smelters closed. There were 12 primary zinc smelters in 1970, but only seven in 1980, three in 1990, and two in 2000. Today, there is one operating primary zinc smelter, in Clarksville, Tennessee, which produces zinc from mines in the East Tennessee and Middle Tennessee districts. All other zinc concentrates are exported and smelted abroad.

Byproducts of zinc

A number of elements are recovered in flue gas and flue dust in zinc smelters. These include the metal

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

and the semi-metals

gallium Gallium is a chemical element with the symbol Ga and atomic number 31. Discovered by French chemist Paul-Émile Lecoq de Boisbaudran in 1875, Gallium is in group 13 of the periodic table and is similar to the other metals of the group ( alum ...

and

germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbo ...

. In 1970, for every ton of zinc produced at a US smelter, there were also recovered 4.2 kilograms of cadmium, 53 grams of germanium, 18 grams of

indium Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 par ...

, and 2.9 grams of

thallium Thallium is a chemical element with the symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes a ...

. These elements are concentrated as impurities in the zinc mineral

sphalerite Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Va ...

. The elements are more abundant in sphalerite from ore deposits with lower formation temperatures, such as Mississippi Valley-type deposits. The Middle and East Tennessee zinc mines are Mississippi Valley-type. Cadmium recovered in

zinc smelting Zinc smelting is the process of converting zinc concentrates ( ores that contain zinc) into pure zinc. Zinc smelting has historically been more difficult than the smelting of other metals, e.g. iron, because in contrast, zinc has a low boiling poi ...

is the only commercial source of cadmium. Gallium and germanium are also recovered some from other sulfide ores. Some germanium is also recovered from aluminum smelting. In previous years, indium and thallium were recovered from zinc smelting, but as of 2015, they were not being recovered from American zinc smelters. According to the British Geological Survey, in 2011, US zinc smelting recovered about 600 tonnes of cadmium, three tonnes of gallium, and three tonnes of germanium.World Mineral Production 2007-11, British Geological Survey, 2013.

Consumption

In 2019, the US consumed 950,000 tons of zinc. Most zinc is used for

galvanizing Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerg ...

, followed by brass and bronze, and zinc-based alloys.

International trade

The United States is a net importer of zinc (87% of consumption). In 2019 it imported 830,000 tonnes of refined zinc metal and products. In the same year, the US exported 870,000 tonnes of zinc in ore concentrates, mostly from the Red Dog Mine in Alaska. During the period 2015-2018, imports were primarily from Canada (64%), Mexico (13%), Australia (7%), and Peru (7%).