Silver mining
Encyclopedia
Silver mining refers to the resource extraction
of the precious metal
element
silver
by mining
.
Silver has been known since ancient times. It is mentioned in the Book of Genesis, and slag heaps found in Asia Minor
and on the islands of the Aegean Sea
indicate that silver was being separated from lead
as early as the 4th millennium BCE. The silver mines at Laurium
were very rich and helped provide a currency for the economy of Ancient Athens. It involved mining the ore in underground galleries, washing the ores and smelting
it to produce the metal. Elaborate washing tables still exist at the site using rain water held in cisterns and collected during the winter months.
Extraction of silver from lead ore was widespread in Roman Britain
as a result of Roman mining very soon after the conquest of the first century AD.
From the mid-15th century silver began to be extracted from copper ores in massive quantities using the liquation
process creating a boost to the mining and metallurgy
industries of Central Europe
.
Vast amounts of silver were brought into the possession of the crowns of Europe after the conquest
of the Americas
from the now Mexican state of Zacatecas
(discovered in 1546) and Potosí
(Bolivia, also discovered in 1546), which triggered a period of inflation in Europe. The conquistador
Francisco Pizarro
was said to have resorted to having his horses shod with silver horseshoes due to the metal's abundance, in contrast to the relative lack of iron in Peru
. Silver, which was extremely valuable in China
, became a global commodity, contributing to the rise of the Spanish Empire
. The rise and fall of its value affected the world market.
Silver mining was a driving force in the settlement of western North America
, with major booms for silver and associated minerals (lead, mostly) in the galena
ore silver is most commonly found in. Notable silver rush
es were in Colorado
, Nevada
, Cobalt, Ontario
, California
and the Kootenay
region of British Columbia
, notably in the Boundary
and "Silvery" Slocan
. The first major silver ore deposits in the United States were discovered at the Comstock Lode
in Virginia City, Nevada
, in 1859.
Silver is found in native form very rarely as nugget
s, but more usually combined with sulfur
, arsenic
, antimony
, or chlorine
and in various ores such as argentite
(Ag2S
) and chlorargyrite
("horn silver," AgCl
).
The principal sources of silver are copper
, copper-nickel
, gold
, lead
, and lead
-zinc
ores obtained from Canada
, (such as Cobalt, Ontario
); Mexico
(such as Batopilas); Peru
; Bolivia
; Australia
; and the United States
.
Mexico
was the world's largest silver producer in 2010. According to the Silver Institute, it produced 128.6 million troy
ounce
s (3,999 metric tons) in 2010, about 17 percent of the annual production of the world. In 2010, total global mine production of silver was approximately 735 million troy ounces.
Silver is commonly extracted from ore by smelting
or chemical leaching. Ore treatment by mercury
amalgamation, such as in the patio process
or pan amalgamation
was widely used through the 1800s, but is seldom used today.
Silver is also produced during the electrolytic
refining of copper and by application of the Parkes process
on lead metal obtained from lead ores that contain small amounts of silver. Commercial grade fine silver is at least 99.9 percent pure silver and purities greater than 99.999 percent are available.
Resource extraction
The related terms natural resource extraction both refer to the practice of locating, acquiring and selling natural resources....
of the precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...
element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
by mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
.
History
Asia Minor
Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...
and on the islands of the Aegean Sea
Aegean Sea
The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...
indicate that silver was being separated from lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
as early as the 4th millennium BCE. The silver mines at Laurium
Laurium
Laurium or Lavrio is a town in southeastern part of Attica, Greece. It is the seat of the municipality of Lavreotiki...
were very rich and helped provide a currency for the economy of Ancient Athens. It involved mining the ore in underground galleries, washing the ores and smelting
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
it to produce the metal. Elaborate washing tables still exist at the site using rain water held in cisterns and collected during the winter months.
Extraction of silver from lead ore was widespread in Roman Britain
Roman Britain
Roman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...
as a result of Roman mining very soon after the conquest of the first century AD.
From the mid-15th century silver began to be extracted from copper ores in massive quantities using the liquation
Liquation
Liquation is a metallurgical method for separating metals from an ore or alloy. The material must be heated until one of the metals starts to melt and drain away from the other and can be collected...
process creating a boost to the mining and metallurgy
Metallurgy
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...
industries of Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...
.
Vast amounts of silver were brought into the possession of the crowns of Europe after the conquest
European colonization of the Americas
The start of the European colonization of the Americas is typically dated to 1492. The first Europeans to reach the Americas were the Vikings during the 11th century, who established several colonies in Greenland and one short-lived settlement in present day Newfoundland...
of the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
from the now Mexican state of Zacatecas
Zacatecas, Zacatecas
Zacatecas is a city and municipality in Mexico and the capital of the state of Zacatecas. It is located in the north central part of the country. The city had its start as a Spanish mining camp in the mid 16th century. Prior to this, the area's rich deposits in silver and other minerals were known...
(discovered in 1546) and Potosí
Potosí
Potosí is a city and the capital of the department of Potosí in Bolivia. It is one of the highest cities in the world by elevation at a nominal . and it was the location of the Spanish colonial mint, now the National Mint of Bolivia...
(Bolivia, also discovered in 1546), which triggered a period of inflation in Europe. The conquistador
Conquistador
Conquistadors were Spanish soldiers, explorers, and adventurers who brought much of the Americas under the control of Spain in the 15th to 16th centuries, following Europe's discovery of the New World by Christopher Columbus in 1492...
Francisco Pizarro
Francisco Pizarro
Francisco Pizarro González, Marquess was a Spanish conquistador, conqueror of the Incan Empire, and founder of Lima, the modern-day capital of the Republic of Peru.-Early life:...
was said to have resorted to having his horses shod with silver horseshoes due to the metal's abundance, in contrast to the relative lack of iron in Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
. Silver, which was extremely valuable in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, became a global commodity, contributing to the rise of the Spanish Empire
Spanish Empire
The Spanish Empire comprised territories and colonies administered directly by Spain in Europe, in America, Africa, Asia and Oceania. It originated during the Age of Exploration and was therefore one of the first global empires. At the time of Habsburgs, Spain reached the peak of its world power....
. The rise and fall of its value affected the world market.
Silver mining was a driving force in the settlement of western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, with major booms for silver and associated minerals (lead, mostly) in the galena
Galena
Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...
ore silver is most commonly found in. Notable silver rush
Silver rush
A Silver rush is the silver-mining equivalent of a gold rush.Notable silver rushes have taken place in Mexico, Argentina, the United States , and Canada...
es were in Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, Cobalt, Ontario
Cobalt, Ontario
Cobalt is a town in the district of Timiskaming, province of Ontario, Canada, with a population of 1,223 In 2001 Cobalt was named "Ontario's Most Historic Town" by a panel of judges on the TV Ontario program Studio 2, and in 2002 the area was designated a National Historic Site.-History:Silver was...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and the Kootenay
Kootenays
The Kootenay Region comprises the southeastern portion of British Columbia. It takes its name from the Kootenay River, which in turn was named for the Ktunaxa First Nation first encountered by explorer David Thompson.-Boundaries:The Kootenays are more or less defined by the Kootenay Land...
region of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, notably in the Boundary
Boundary Country
The Boundary Country is a historical designation for a district in southern British Columbia lying, as its name suggests, along the boundary between Canada and the United States. It lies to the east of the southern Okanagan Valley and to the west of the West Kootenay. It is often included in...
and "Silvery" Slocan
Slocan
Slocan is the name of a river, lake and valley-region in the West Kootenay region of the Canadian province of British Columbia. The name Slocan is derived from the Sinixt First Nations people's word meaning "to strike or pierce on head" and was derived from their practice of harpooning salmon...
. The first major silver ore deposits in the United States were discovered at the Comstock Lode
Comstock Lode
The Comstock Lode was the first major U.S. discovery of silver ore, located under what is now Virginia City, Nevada, on the eastern slope of Mount Davidson, a peak in the Virginia Range. After the discovery was made public in 1859, prospectors rushed to the area and scrambled to stake their claims...
in Virginia City, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, in 1859.
Areas
Nugget
Nugget may refer to:* Gold nugget, a piece of gold produced through mining and extraction* Chicken nugget, a lump of breaded or battered chicken* Mosin Nagant, a family of bolt action military rifles* North Bay Nugget, a daily newspaper...
s, but more usually combined with sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
, arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
, antimony
Antimony
Antimony is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite...
, or chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
and in various ores such as argentite
Argentite
Argentite was primarily treated as a mineral belonging to the galena group, cubic silver sulfide , occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre. All these forms are structurally not argentite, but...
(Ag2S
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
) and chlorargyrite
Chlorargyrite
Chlorargyrite is the mineral form of silver chloride . Chlorargyrite occurs as a secondary mineral phase in the oxidation of silver mineral deposits. It crystallizes in the isometric - hexoctahedral crystal class. Typically massive to columnar in occurrence it also has been found as colorless to...
("horn silver," AgCl
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
).
The principal sources of silver are copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, copper-nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
, gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
, lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
, and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
-zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
ores obtained from Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, (such as Cobalt, Ontario
Cobalt, Ontario
Cobalt is a town in the district of Timiskaming, province of Ontario, Canada, with a population of 1,223 In 2001 Cobalt was named "Ontario's Most Historic Town" by a panel of judges on the TV Ontario program Studio 2, and in 2002 the area was designated a National Historic Site.-History:Silver was...
); Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
(such as Batopilas); Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
; Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
; Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
; and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
was the world's largest silver producer in 2010. According to the Silver Institute, it produced 128.6 million troy
Troy weight
Troy weight is a system of units of mass customarily used for precious metals, gemstones, and black powder.There are 12 troy ounces per troy pound, rather than the 16 ounces per pound found in the more common avoirdupois system. The troy ounce is 480 grains, compared with the avoirdupois ounce,...
ounce
Ounce
The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
s (3,999 metric tons) in 2010, about 17 percent of the annual production of the world. In 2010, total global mine production of silver was approximately 735 million troy ounces.
| Mine | Country | 2010 Production |
|---|---|---|
| Cannington Silver/Lead/Zinc Mine | Australia | 38.6 Moz |
| Fresnillo Silver Mine | Mexico | 38.6 Moz |
| San Cristobal Polymetallic Mine | Bolivia | 19.4 Moz |
| Antamina Copper/Zinc Mine | Peru | 14.9 Moz |
| Rudna Copper Mine | Poland | 14.9 Moz |
| Penasquito Gold/Silver Mine | Mexico | 13.9 Moz |
| Project | Country | Anticipated Annual Production Capacity (due within five years) |
|---|---|---|
| Pascua Lama | Chile | 25.0 Moz |
| Navidad | Argentina | 15.0 Moz |
| Juanicipio | Mexico | 14.0 Moz |
| Malku Khota | Bolivia | 13.2 Moz |
| Hackett River | Canada | 13.1 Moz |
| Corani | Peru | 10.0 Moz |
Ore processing
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
or chemical leaching. Ore treatment by mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
amalgamation, such as in the patio process
Patio process
The patio process was a process used to extract silver from ore. The process was invented by Bartolomé de Medina in Pachuca, New Spain , in 1554. The patio process was the first process to use mercury amalgamation to recover silver from ore. It replaced smelting as the primary method of extracting...
or pan amalgamation
Pan amalgamation
The Pan amalgamation process is a method to extract silver from ore, using mercury. The process was widely used from 1609 through the 19th century; it is no longer used....
was widely used through the 1800s, but is seldom used today.
Silver is also produced during the electrolytic
Electrolysis
In chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...
refining of copper and by application of the Parkes process
Parkes process
The Parkes process is a pyrometallurgical industrial process for removing silver from lead, during the production of bullion. It is an example of liquid-liquid extraction....
on lead metal obtained from lead ores that contain small amounts of silver. Commercial grade fine silver is at least 99.9 percent pure silver and purities greater than 99.999 percent are available.