Encyclopedia of Global Resources part 147 pot

Category: Mineral and other nonliving resources Where Found Zinc is widely distributed in the Earth’s crust, with an average crustal abundance of 70 parts per million 0.007 percent.. The

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Web Site

U.S Geological Survey

Mineral Information: Zeolites Statistics and

Information

http://minerals.usgs.gov/minerals/pubs/

commodity/zeolites/

See also: Volcanoes; Water; Water pollution and water

pollution control

Zimbabwe

Categories: Countries; government and resources

Zimbabwe has the second largest reserve of gold on the

African continent and the second largest reserve of

platinum in the world The country also boasts the

largest elephant herd in the world as well as a sizable

impala herd; safari tours have historically been an

im-portant means of support for the local population.

The Country

Zimbabwe is in the southeastern corner of Africa,

bor-dered to the north by Zambia, to the east by

Mozam-bique, to the west by Botswana, and to the south by

South Africa In 2008, the country’s gross domestic

product was estimated at $2.3 billion Of this amount,

agriculture accounted for 18.1 percent, industry

counted for 22.6 percent, and the services sector

ac-counted for 59.3 percent The total value of mineral

production in Zimbabwe exceeds $500 million per

year The mining sector of the economy employs at

least sixty thousand people and accounts for more

than 40 percent of the total export revenues of the

country

Of the total land area, 49.2 percent is forest, and

this consists of mopane and dry Miombo woodland

Grasslands, both low- and high-altitude types,

consti-tute another important ecosystem The Zambezi River,

which forms the border between Zimbabwe and

Zam-bia, is an important waterway of the country

Gold

Africa has about 30 percent of the Earth’s mineral

re-serves, including 40 percent of the world’s gold Gold

is the most important mineral commodity of

Zimba-bwe and the second-leading export commodity,

pro-viding an annual output of $194 million In 2007, 5.7

metric tons of gold were produced by the country’s mines Zimbabwe possesses the second largest gold re-serves in Africa

The Freda Rebecca Mine, located close to Bindura, north of the capital city of Harare, is said to be the richest in the country Ninety thousand metric tons of ore are processed at this mine each month Freda Rebecca is owned by AngloGols Ashanti, a large ming firm Other important gold-minming companies in-clude Falcon Gold, one of the oldest in Zimbabwe; Anglo American; Rio Tinto Zimbabwe; Consolidated Trillion Resources; Independence Gold; Delta Gold; and Reedbuck Gold Central Rand Gold is a holding company for a number of smaller gold-mining and exploration firms

In addition to traditional, large-scale gold-mining operations, nearly everyone in Zimbabwe pans for gold and seeks the mineral in tailings left from closed mines

Diamonds

In Zimbabwe, diamonds, among the world’s most precious minerals, were first discovered in 1997 at Murowa, about 40 kilometers from the town of Zvisha-vane in the south-central portion of the country Three kimberlite pipes containing diamond ore were located at the site The Rio Tinto Group, which is the third largest producer of rough diamonds in the world and also owns gold mines in Zimbabwe, has worked only two of these kimberlite pipes Full-scale production is expected to process 181,400 metric tons

of ore per year Another important diamond mine in the country is the River Ranch mine, a combination open-pit and underground operation De Beers owns

75 percent of River Ranch

As of late 2008, diamond production in Zimbabwe totaled approximately fourteen million carats How-ever, a tremendous amount of illegal mining has oc-curred and contributes to a sizable black market prob-lem The government is attempting to control the diamond situation and the accompanying violence as-sociated with the black market

Platinum Among the world’s scarcest minerals, found at a con-centration of only 0.003 part per billion in the Earth’s crust, platinum is a highly prized metal that is thirty times rarer than gold Its properties of malleability, ductility, and corrosion resistance make it a valuable component used in many industries Platinum is

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some-Zimbabwe: Resources at a Glance

Official name: Republic of Zimbabwe Government: Parliamentary democracy Capital city: Harare

Area: 150,883 mi2; 390,757 km2

Population (2009 est.): 11,392,629 Language: English

Monetary unit: Zimbabwean dollar

Economic summary:

GDP composition by sector (2008 est.): agriculture, 18.1%; industry, 22.6%; services, 59.3%

Natural resources: coal, chromium ore, asbestos, gold, diamonds, nickel, copper, iron ore, vanadium, lithium, tin,

platinum group metals

Land use (2005): arable land, 8.24%; permanent crops, 0.33%; other, 91.43%

Industries: mining (coal, gold, platinum, copper, nickel, tin, clay, numerous metallic and nonmetallic ores), steel,

wood products, cement, chemicals, fertilizer, clothing and footwear, foodstuffs, beverages

Agricultural products: corn, cotton, tobacco, wheat, coffee, sugarcane, peanuts, sheep, goats, pigs

Exports (2008 est.): $1.321 billion

Commodities exported: platinum, cotton, tobacco, gold, ferroalloys, textiles/clothing

Imports (2008 est.): $1.915 billion

Commodities imported: machinery and transport equipment, other manufactures, chemicals, fuels

Labor force (2008 est.): 4.039 million

Labor force by occupation (1996): agriculture, 66%; industry, 10%; services, 24%

Energy resources:

Electricity production (2006 est.): 9.467 billion kWh

Electricity consumption (2006 est.): 11.59 billion kWh

Electricity exports (2006 est.): 34 million kWh

Electricity imports (2006 est.): 2.867 billion kWh

Natural gas production (2007 est.): 0 m3

Natural gas consumption (2007 est.): 0 m3

Natural gas exports (2007 est.): 0 m3

Natural gas imports (2007 est.): 0 m3

Oil production (2007 est.): 0 bbl/day Oil imports (2005 est.): 15,800 bbl/day Oil proved reserves ( Jan 2006 est.): 0 bbl Source: Data from The World Factbook 2009 Washington, D.C.: Central Intelligence Agency, 2009.

Notes: Data are the most recent tracked by the CIA Values are given in U.S dollars Abbreviations: bbl/day = barrels per day;

GDP = gross domestic product; km 2 = square kilometers; kWh = kilowatt-hours; m 3 = cubic meters; mi 2 = square miles.

Harare

Namibia

South Africa

Angola

Mo zam bique

Botswana

Zambia

Ma la wi

Zimbabwe

I n d i a n

O c e a n

Swaziland

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times used as a component of dental fillings and as a

catalyst in the catalytic converters of automobiles It

also serves a number of important functions in the

manufacture of laboratory equipment such as

cruci-bles, tongs, funnels, and combustion instruments

Additionally, platinum is valued by many people for

jewelry

Leading world producers of platinum are South

Af-rica (with 80 percent of the planet’s share of

produc-tion), Russia, and Canada Although Zimbabwe

pro-duces approximately only 2 percent of the world’s

platinum group metals, this product is an important

export for the country Found in nickel and copper

ores, platinum is also found in native deposits,

includ-ing those along Zimbabwe’s Great Dyke, a geological

feature that runs north to south for about 550

kilome-ters through the central portion of the country

Plati-num deposits were found in this area in 1925, but only

in more recent times has mining become profitable

Union Carbide began trial mining between 1966

and 1975 at the Mimosa Mine, now Zimbabwe’s

old-est Obtained by Zimasco Ltd in 1992, Mimosa

pro-cesses approximately 27,000 metric tons of ore per

month for a production total of 2,400 kilograms of

platinum each year The mine also supplies palladium

and rhodium, other platinum group metals In 2007,

1,850 kilograms of palladium and 190 kilograms of

rhodium were produced

The Zimplats Mine, also a large producer of

num group metals, produced 3,000 kilograms of

plati-num, 2,440 kilograms of palladium, and 264

kilo-grams of rhodium in 2007 Other important mines

along the Great Dyke include Hartley Platinum, Ngezi,

and Unki Ngezi’s production totaled 2,550 kilograms

in 2006, and Unki was expected to generate about

1,644 kilograms by 2010

Lithium

Although Zimbabwe is not one of the world’s leading

producers of lithium, the country is still important as

a lithium exporter because reserves of this alkali

metal are rare Chile is the leading producer of

lith-ium, followed by Argentina Australia, Brazil, Canada,

Portugal, and Zimbabwe are the other nations for

which lithium is a vital export

Lithium has many uses in industry It has been

used in glass manufacturing for many years because it

lowers the melting point of glass and allows for

con-tainers to be made with thinner walls as well as with

lighter weight Thermal and shock-resistant cookware

is manufactured using lithium, and the metal acts as a catalyst in synthetic rubber and plastic production Lithium carbonate in a pharmaceutical formulation provides a valuable drug for treating manic depres-sion

Probably the most important modern use of lith-ium has been as a component of rechargeable batter-ies Lithium batteries are used as the power sources for 60 percent of all cell phones and 90 percent of all laptop computers

In 2000, Zimbabwe produced 38,000 metric tons of lithium; production increased by 110 percent be-tween 2003 and 2004 Subsequent figures are difficult

to obtain because of the continuing instability of Zim-babwe’s political and economic situation The Glen Cove Mine, operated by Bikita Minerals Ltd., contin-ues production and is considered to have a remark-ably high-quality grade of lithium This particular mine has provided the United States Atomic Energy Commission with about 30 percent of its lithium hy-droxide stockpile

Chromium Zimbabwe boasts more than 50 percent of the world’s reserves of chromite, and together South Africa and Zimbabwe possess 90 percent of Earth’s supply of this valuable ore Chromium is vital in the production of stainless steel, nonferrous (non-iron) alloys, metal-plating processes, and the manufacture of refrac-tories Like lithium and platinum, chromium is im-portant as a catalyst for manufacturing processes For the United States, the only domestic source of chro-mium is through recycling, so the country imports much of its needed supply from South Africa and Zim-babwe

The two major Zimbabwean chromite mines are Mutorashanga and the Torwood and Valley Mine The large companies of Zimasco and Zimbabwe Al-loys International own both the ore-mining and ferrochromium production components, allowing for the vertical integration of this industry

Tobacco Zimbabwe is one of the world’s major tobacco export-ers, ranking seventh, as of 2009, after Brazil, the United States, India, Malawi, Italy, and China For many years, the country ranked as one of the top four tobacco producers in the world Tobacco accounts for more than 50 percent of Zimbabwe’s total agricul-tural exports and represents 30 percent of the

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coun-try’s total exports Sales of the crop earn about seven

times more than sales of corn, about twenty-two times

more than cotton, and sixty times more than

soy-beans Virtually all the tobacco crop (98 percent) is

exported because there is little domestic production

of cigarettes

Tobacco production provides employment for

ap-proximately 5 percent of the country’s labor force

and also contributes to employment for those in the

coal-mining, transportation, hospitality, and service

sectors of the economy Most tobacco farming is done

by about two thousand large-scale, commercial

grow-ers who utilize modern farming techniques,

includ-ing irrigation These large growers account for 95

per-cent of total crop production and plant on about 87

percent of the available land About sixteen thousand

small-scale dryland farmers raise the remaining 5

per-cent of the country’s tobacco

Three types of tobacco are grown in Zimbabwe

Flue-cured tobacco is raised in the parts of the

coun-try with better rainfall totals, and this encompasses

areas north and east of the capital of Harare Burley

tobacco is grown in the northeastern and eastern

highland regions, where there is both good rainfall

and high humidity, which is necessary for the curing

of this particular type of tobacco Oriental tobacco is

grown primarily by small-scale farmers in Masvingo

Province

Most tobacco farmers practice a five-year rotation

schedule and grow other crops within the rotation

cycle Soybeans, wheat, corn, and livestock are all

pro-duced on tobacco land, and some farmers have turned

to less traditional crops such as export roses,

vegeta-bles for sale to grocery stores, coffee, and paprika

The change to a greater diversity of crops became

nec-essary because of the worldwide campaign to reduce

the use of tobacco products such as cigarettes

For most of the 2000’s, Zimbabwe produced an

av-erage of 181,000 metric tons of tobacco per year, but

in the later years of the decade, production totals

dropped steeply Fewer than 54,000 metric tons were

produced in 2008 As mentioned, the global health

campaign against tobacco use has contributed

signifi-cantly to a drop in production, but severe drought

and shortages of diesel fuel and fertilizer have also

affected this agricultural sector adversely

Cotton

Cotton is Zimbabwe’s second most important

agricul-tural export Approximately 200,000 small farms

pro-duce 98 percent of the cotton crop in the country The amount of cotton produced has been steadily in-creasing In 2007, production totaled 99,700 metric tons; in 2008, 370,000 hectares were planted and har-vested, with seed cotton production reaching 300,000 metric tons and lint production 123,000 metric tons Average yield was 0.81 metric ton per hectare Since 1994, the small-scale cotton growers in Zim-babwe have sold their seed cotton to the Cotton Com-pany of Zimbabwe (Cottco) This comCom-pany is the larg-est buying, processing, and marketing operation in the country, although Cargill and Romsdal also have a share of the cotton market The ginners and mer-chants of these companies provide seed, fertilizer, and pesticides to the growers on credit In turn, the growers sign contracts promising to sell all of their cotton back to the contractors

Large-scale cotton farming takes place in the cen-tral, northern, and eastern sections of Mashonaland, while most small-scale production is in the Gokwe, Gwanda, and Kezi areas of Zimbabwe Alber and long staple varieties of cotton are grown on all farms, and the quality of this cotton is ranked as “high” because there are not many contaminants and not much dam-age to the cotton

Although the textile and garment industries have been well established since the 1930’s in Zimbabwe, these industries and the accompanying cotton pro-duction that supports them have experienced a num-ber of problems Foreign currency problems and the extreme political instability of Zimbabwe have af-fected all of the country’s industries adversely, and the cotton business is no exception Farmers who have been “resettled” by forced government intervention

on former commercial farms are unskilled and have little experience in cotton production There are also

no gins for small farms other than the ones owned by the national companies such as Cottco and Cargill Extreme drought in the region during recent years has also negatively affected cotton as well as many other crops

Some farmers have begun to break a law that states that all cotton stalks must be destroyed at least fifty days before the next season’s planting These farmers have been growing cotton by using the previous year’s stalks, a practice that has led to increased infestation

of pink bollworm, one of the primary cotton pests In spite of these problems, cotton continues to be an im-portant export crop for Zimbabwe and may surpass tobacco as the number one crop of the country

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Other Resources

One of Zimbabwe’s most important resources is its

wildlife and ecology: Tourism is the third largest

income-producing industry in Zimbabwe, employing

about 200,000 people The country has a variety of

na-tional parks, all of which host an astonishing variety of

flora and fauna Various licenses for tourists, park

fees, and concessions within the parks provide

in-come opportunities for local residents

The national parks include Chimanimani,

Chizar-ira, Gonarezhou, Hwange, Kazuma Pan, Mana Pools,

Matusadona, Matelo, Nyanga, Victoria Falls, and

Zam-bezi Most of the parks host large numbers of the

more common species of savanna wildlife, including

roan, sable, impala, eland, cape buffalo, zebra, and

elephant Lions, leopards, and cheetahs are among

the large predators that may also be seen in a few of

the parks, including Gonarezhou and Kazuma Pan

Chizarira National Park also supports herds of the ex-tremely rare black rhinoceroses The tsessebe, a sa-vanna antelope, and white rhinoceroses are found in Zambezi National Park Hwange, the largest game re-serve in Zimbabwe, located close to the Kalahari Desert, is home to hippopotamuses, crocodiles, brown hyenas, gemsboks, and African wild dogs as well as a large elephant herd

Victoria Falls and Zambezi national parks are lo-cated along Zimbabwe’s border with Zambia and are visited as much for the spectacular natural wonder of waterfalls as for the diversity of wildlife Victoria Falls actually consists of five separate falls, four within babwe and one (Eastern Cataract) in Zambia In Zim-babwe, the Devil’s Cataract, Main Falls, Rainbow Falls, and Horseshoe Falls provide awe-inspiring views for the tourist

Since its inception in 1989, the Communal Areas Management Program for Indigenous Resources, better known as CAMPFIRE, has provided money-making opportunities for local people by leasing land

to tour companies However, in order for ecotourism

to continue to provide a means of support for Zim-babweans, the political situation in the country must stabilize

Lenela Glass-Godwin

Further Reading

Bartholomew, D S Base Metal and Industrial Mineral Deposits of Zimbabwe Reprint Harare: Zimbabwe

Geological Survey, 1992

Coakley, George J The Mineral Industry of Zimbabwe.

Washington, D.C.: U.S Geological Survey, 2000

Duffy, Rosaleen Killing for Conservation: Wildlife Policy

in Zimbabwe London: International African

Insti-tute, 2000

Ebensperger, Arlene, P Maxwell, and C Moscoso

“The Lithium Industry: Its Recent Evolution and

Future Prospects.” Resources Policy 30, no 3 (2005):

218-231

George, M W Platinum Group Metals Washington,

D.C.: U.S Geological Survey, 2007

Hulme, David, and Marshall Murphree, eds African Wildlife and Livelihoods: The Promise and Performance

of Community Conser vation Portsmouth, N.H.:

James Currey, 2001

See also: Chromium; Cotton; Diamond; Gold; Lith-ium; Platinum and the platinum group metals; South Africa

Victoria Falls is one of the many natural wonders found in

Zim-babwe (©Lucian Coman/Dreamstime.com)

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Category: Mineral and other nonliving resources

Where Found

Zinc is widely distributed in the Earth’s crust, with an

average crustal abundance of 70 parts per million

(0.007 percent) It has been concentrated into several

types of ore deposits from which it is mined as the

principal metal or as a by-product The principal ore

mineral is sphalerite (ZnS), also known as zinc blende

or marmatite China, Japan, Australia, and Canada

are the world’s largest suppliers of zinc

Primary Uses

Zinc is a widely used metal, but its presence is

gener-ally not obvious to the public The largest single use is

in galvanizing, a process in which iron or carbon steel

is covered with a thin coating of zinc to prevent

rust-ing Zinc is also widely used in brass alloys and other

compounds ranging from pharmaceuticals to rubber

tires to paints

Technical Definition

Zinc (symbol Zn), atomic number 30, belongs to

Group IIB of the periodic table of the elements and

exhibits some chemical and physical similarities to

cadmium It has five naturally occurring stable

iso-topes, with masses of 64, 66, 67, 68, and 70, and it has

an average atomic weight of 65.38 Pure zinc is a

mal-leable, bluish-white metal that crystallizes in a

hexago-nal structure and that has a density of 7.13 grams per

cubic centimeter It has a melting point of 419.6°

Cel-sius and a boiling point of 907° CelCel-sius

Description, Distribution, and Forms

Zinc is one of the most widely used metals; however,

throughout much of its history it was not recognized

as a distinct metal Zinc is nearly ubiquitous in trace

amounts and is essential for the normal growth and

development of plants and animals It occurs in more

than twenty metalloenzymes and promotes healing of

wounds and burns; furthermore, zinc deficiency has

been shown to have severe effects on reproduction

and tissue growth in laboratory animals Zinc

defi-ciency in soils leads to reduced productivity but can be

remedied by the application of trace amounts of zinc

in fertilizers

Numerous studies of zinc in the environment have

demonstrated that severe zinc pollution is extremely rare and that zinc contamination rarely becomes a problem for plants or animals In general, the only time that zinc concentrations can rise to harmful lev-els is if the pH is very low and the sources of zinc are very large Zinc is readily adsorbed onto clays or pre-cipitates from solutions at neutral and high pH values Zinc and its compounds are relatively nontoxic to hu-mans when taken in normal dosages Very large dos-ages can cause gastroenteritis; however, reports of such poisoning are limited to a few rare cases of the consumption of acidic beverages having been kept in galvanized containers Workplace poisoning has been only rarely reported as the result of inhaling zinc dust

or fumes; the human body is quite efficient in the elimination of excess zinc

Zinc has been mobilized by fluids in the Earth’s crust and precipitated into many types of ore deposits Although there are many zinc-bearing minerals, the only mineral that serves as an economic source of zinc

in mining is sphalerite (ZnS) The principal types of ores are carbonate-hosted lead-zinc ores (Mississippi Valley-type ores, so called because of their abundance

in parts of the Mississippi Valley drainage system, es-pecially Missouri), hydrothermal vein deposits, and polymetallic massive sulfide ores formed where hy-drothermal fluids have deposited complex ores in sedimentary basins or in masses of volcanic rocks The Mississippi Valley-type ores occur in limestone and do-lomite beds where there has been infiltration of rela-tively low-temperature (75° to 150° Celsius) fluids that have already leached zinc (and commonly lead) from thick sequences of sedimentary rocks The zinc is de-posited as the mineral sphalerite, most often as light yellow coatings on, and as fracture fillings in, the car-bonate rocks This sphalerite typically contains small amounts (0.5 percent) of cadmium and iron and trace amounts (less than 0.1 percent) of germanium, gallium, and indium in solid solution Consequently, the zinc ores serve as the world’s major sources of these rare elements, which are recovered during re-fining

Zinc-bearing hydrothermal deposits commonly oc-cur as veins from centimeters to meters in thickness associated with granitic to intermediate igneous rocks The sphalerite in these ores is typically very dark brown to black and contains 5 to 10 percent iron sub-stituting for the zinc; it has commonly been called

“blackjack” or marmatite The zinc ores of the volca-nic and sedimentary deposits are similar

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mineralogi-cally to those of the vein deposits with the sphalerite

intermixed with pyrite (FeS2), chalcopyrite (CuFeS2),

and galena (PbS) These deposits occur where

frac-tures and faults have allowed deeply circulating

groundwaters, containing small amounts of dissolved

metals, to discharge and precipitate complex masses

of sulfides In recent years modern examples of these

types of deposit have been observed forming at

oce-anic spreading centers such as the East Pacific Rise

At these sites, hydrothermal fluids issuing from the

seafloor fractures are depositing polymetallic sulfide

mounds that are rich in zinc Although all the zinc in

ore deposits occurs as sphalerite, much of the zinc

forming in modern seafloor deposits is wurtzite,

an-other form of ZnS; the wurtzite gradually is converted

into sphalerite after deposition

In 2008, world zinc production was about 11

mil-lion metric tons World reserves are thought to be

about 180 million metric tons The world reserve

base, which includes zinc that will likely become

eco-nomic to mine, is about 480 million metric tons

United States production is dominated by Alaska,

Tennessee, New York, Missouri, and Colorado and has been in the range of 800,000 metric tons per year; total U.S reserves are about 14 million metric tons, and the U.S reserve base is about 90 million metric tons Accordingly, U.S mines will be able to continue

to produce zinc at about the same rates for several de-cades

History Zinc has been found in some bronze and brass arti-facts made five thousand years ago, and a few early ex-amples of nearly pure zinc metal date back to about

500 b.c.e Significant zinc production appears to have begun in China in the sixth century c.e Subsequent large-scale production is known from India about

1000 c.e., but zinc appears in European usage only around the sixteenth century The technology of zinc smelting is thought to have been developed in China and brought to Europe about 1730

The use of zinc in the United States began in 1835, when it was desired to produce alloys for the manufac-ture of the U.S standard units of weights and

mea-Data from the U.S Geological Survey, U.S Government Printing Office, 2009.

Source: Mineral Commodity Summaries, 2009

1,510,000 660,000

3,200,000 420,000

460,000

1,450,000 770,000

2,840,000

Metric Tons

3,500,000 3,000,000

2,500,000 2,000,000

1,500,000 1,000,000

500,000 United States

Kazakhstan

China

Canada

Australia

Mexico

Peru

Other countries

Zinc: World Mine Production, 2008

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sures Mining in the United States began about 1850

in rich ores in New Jersey and Pennsylvania A smelter

was built in 1859 By 1900 mines had been developed

in a number of other states, especially along the

Mis-sissippi Valley

Obtaining Zinc

Zinc ores are mined by underground and surface

mining methods, depending upon the depth of the

deposit below the surface Generally ores must

con-tain 2.5 to 3.0 percent zinc or about 4 to 5 percent

sphalerite to be economic; this percentage is

equiva-lent to a concentration factor of about four hundred

times the average abundance of zinc in the Earth’s

crust In order to recover the zinc, the ores are crushed

finely enough that the individual mineral grains may

be separated by the froth flotation process This

pro-cess selectively removes the sphalerite grains as they

attach themselves to small bubbles and float off the

surface of a suspension that contains many kinds of

minerals The separation yields a concentrate that

contains about 55 to 65 percent zinc, depending

upon the purity of the sphalerite Other valuable

metals—such as cadmium, germanium, gallium, and

indium—that are present in small amounts in the

sphalerite are separated during selective smelting and

refining In most smelters, the zinc sulfide is roasted

to remove the sulfur and to produce zinc oxide, which

is then leached with sulfuric acid to form a zinc sulfate

solution After the solution is purified, the zinc is

removed in electrolytic cells and precipitates on large

aluminum cathodes Further refining is accomplished

by distilling the zinc in a vapor form, which is then

recondensed Zinc recycling accounts for a relatively

insignificant percentage of demand because so much

of the zinc is used in forms for which recycling is

diffi-cult or inefficient

Uses of Zinc

Zinc metal and zinc compounds have broad uses, but

many applications are not easily visible or known to

those who benefit from them About 90 percent of

zinc is used in the metallic form; the remainder is

used as zinc oxide and a variety of other compounds

More that half of metallic zinc usage is for the

galva-nizing of iron and steel for construction,

transporta-tion, electrical, and machinery purposes The

appli-cation of the zinc, either by dipping the iron and steel

into molten zinc or by electrolytic plating, provides a

coating that greatly reduces the rusting of iron and

steel Much of the use of such galvanized materials is

on the body parts of motor vehicles Many construc-tion materials, from nails to bridge parts, are also gal-vanized to reduce corrosion

Die-cast zinc materials are also widely used in han-dles, grills, gauges, housings, and assorted hardware, much of it in vehicles The modern American auto-mobile can contain as much as 18 kilograms of zinc Zinc is also used as a sacrificial anode on ships, oil rigs, and other structures exposed to seawater These an-odes corrode as the result of natural electrical cells that develop, and in the process they prevent the cor-rosion of other metals Beginning in 1983, zinc was used in the minting of United States one-cent coins; the penny is composed of 95 percent zinc

Zinc is a basic component of the copper-based alloy brass, which has served humankind for thousands of years Brass is widely used in shell casings for ammuni-tion, in tubing, in motors, in refrigeration equipment, and in communication and electronic devices Zinc dust and zinc oxide have been used in corrosion-inhibiting primer paints for application on metals Zinc dust is also used in the manufacture of alkaline dry-cell batteries Zinc oxide and other compounds

Commodity Summaries, 2009

Data from the U.S Geological Survey,

U.S Government Printing Office, 2009.

Galvanizing 55%

Alloys 21%

Brass &

bronze 16%

Other 8%

U.S End Uses of Zinc

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such as chlorides, sulfates, and sulfides are widely

used in chemical catalysts, welding and soldering

fluxes, paints, fungicides and pharmaceuticals, and

phosphors for cathode tubes and radar scopes; they

are also used as additives in lubricating oils and greases

and in agricultural products

James R Craig

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