Silver mining is the
extraction of
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
from minerals, starting with
mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...
. Because silver is often found in intimate combination with other metals, its extraction requires elaborate technologies. In 2008, ca.25,900 metric tons were consumed worldwide, most of which came from mining.
Silver sources
![SilverOreUSGOV](https://upload.wikimedia.org/wikipedia/commons/1/1f/SilverOreUSGOV.jpg)
Silver-bearing ore typically contains very little silver, with much higher percentages of copper and lead. Specific minerals include
argentite
In mineralogy, argentite (from the Latin ''argentum'', silver) is cubic silver sulfide (Ag2S), which can only exist at temperatures above 173 °C, 177 °C or 179 °C. When it cools to ordinary temperatures it turns into its monocl ...
(Ag
2 S),
chlorargyrite
Chlorargyrite is the mineral form of silver chloride (AgCl). 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 colum ...
("horn silver," Ag
Cl),
polybasite
Polybasite is a sulfosalt mineral of silver, copper, antimony and arsenic. Its chemical formula is .
It forms black monoclinic crystals (thin, tabular, with six corners) which can show dark red internal reflections. It has a Mohs hardness of 2.5 ...
(Ag, Cu)
16Sb
2S
11), and
proustite
Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3 As S3, known also as light red silver or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from whi ...
(Ag
3AsS
3). Silver mainly occurs as a contaminant in
chalcopyrite
Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mo ...
and
galena
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Galena is one of the most abundant and widely distributed sulfide minerals. It cryst ...
, important ores of
copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
and
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
, respectively.
[Kassianidou, V. 2003. Early Extraction of Silver from Complex Polymetallic Ores, in Craddock, P.T. and Lang, J (eds) Mining and Metal production through the Ages. London, British Museum Press: 198–206]
Some ores are actually mined explicitly for their silver value vs the silver being a byproduct of other metals. However silver is only found rarely in a
native
Native may refer to:
People
* Jus soli, citizenship by right of birth
* Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory
** Native Americans (disambiguation)
In arts and entert ...
form as nuggets, in placer deposits, and veins.
[Reddy, Rohan, 2019. Silver, Explained. Global X. https://www.globalxetfs.com/silver-explained/]
Excavation
Methods for mining silver depend on the grade of the ore, its depth, host rock, and other economic factors. Commonly, silver ore is obtained from
open pit mines
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock (geology), rock or minerals from the earth from an open-air pit, sometimes known as a Borrow pit, b ...
, and underground
drifts and
shafts
''Shafts'' was an English feminist magazine produced by Margaret Sibthorp from 1892 until 1899. Initially published weekly and priced at one penny, its themes included votes for women, women's education, and radical attitudes towards vivisection, ...
.
[Hilliard, Henry E., 2003. "Silver". USGS.] Explosives are frequently used to shatter veins into manageable pieces, which are transported via mine cars and then lifted to the surface.
The process can be dangerous.
Ore processing
Once removed from the mine, silver-containing ore is crushed (
commutation
Commute, commutation or commutative may refer to:
* Commuting, the process of travelling between a place of residence and a place of work
Mathematics
* Commutative property, a property of a mathematical operation whose result is insensitive to th ...
) into a fine powder to expose individual grains to chemical processing. As a byproduct of mining of lead and copper, silver ores are often purified by
froth flotation
Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in mineral processing, paper recycling and waste-water treatment industries. Historically this was first used in the mining industry, wher ...
. After froth flotation, silver is extracted by a
cyanide process
Gold cyanidation (also known as the cyanide process or the MacArthur-Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly ...
, akin to technology used for
gold extraction
Gold extraction refers to the processes required to extract gold from its ores. The great majority of gold is extracted from dilute ores using a combination of chemical processes. About 2000 tons are obtained from the earth annually, plus anothe ...
.
[ In some cases, the ore is treated by ]smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a ch ...
before cyanide treatment. Silver is also produced during the electrolytic
An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dis ...
refining of copper and by application of the Parkes process
The Parkes process is a pyrometallurgical industrial process for removing silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-Europ ...
on lead ores. Commercial grade fine silver is at least 99.9 percent pure silver, and purities greater than 99.999 percent are available.
Recycling
About 5000 tons of silver are annually recovered from scrap.[ Jewelry, photographic film, silverware, coins, electronics are sources of recyclable silver.]
Production areas
The principal sources of silver are copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
, copper-nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
, gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
, lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
, and lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
-zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
ores obtained from Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...
, Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
, Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
, Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
and 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 states, a federal district, five major unincorporated territorie ...
.
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
was the world's largest silver producer in 2014, producing 5,000 metric ton
The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States c ...
s (161 million troy ounce
Troy weight is a system of units of mass that originated in 15th-century England, and is primarily used in the precious metals industry. The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 pennyweights), and the ...
s), 18.7 percent of the 26,800 tonne (862 million troy ounce) production of the world.
History
Silver mining has been undertaken since as early as the 5th century BCE. As silver is a precious metal
Precious metals are rare, naturally occurring metallic chemical elements of high economic value.
Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. ...
often used for coins
A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to ...
and bullion, its mining has historically often been lucrative. As with other precious metals such as gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
or platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver".
Platinu ...
, newly discovered deposits of silver ore have sparked silver rush
A silver rush is the silver-mining equivalent of a gold rush, where the discovery of silver-bearing ore sparks a mass migration of individuals seeking wealth in the new mining region.
Notable silver rushes have taken place in Mexico, Chile, the U ...
es of miners seeking their fortunes. In recent centuries, large deposits were discovered and mined in the Americas, influencing the growth and development of Mexico, Andean countries such as Bolivia, Chile, Argentina and Peru, as well as Canada and the United States.
Silver has been known since ancient times. Silver is mentioned in the Book of Genesis
The Book of Genesis (from Greek ; Hebrew: בְּרֵאשִׁית ''Bəreʾšīt'', "In hebeginning") is the first book of the Hebrew Bible and the Christian Old Testament. Its Hebrew name is the same as its first word, ( "In the beginning") ...
, and slag heaps found in Asia Minor
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
and on the islands of the Aegean Sea
The Aegean Sea ; tr, Ege Denizi (Greek language, Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish language, Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It ...
indicate that silver was being separated from lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
as early as the 4th millennium BC
The 4th millennium BC spanned the years 4000 BC to 3001 BC. Some of the major changes in human culture during this time included the beginning of the Bronze Age and the invention of writing, which played a major role in starting recorded history. ...
. The silver mines at Laurium
Laurium or Lavrio ( ell, Λαύριο; grc, Λαύρειον (later ); before early 11th century BC: Θορικός ''Thorikos''; from Middle Ages until 1908: Εργαστήρια ''Ergastiria'') is a town in southeastern part of Attica, Greec ...
were very rich and helped provide a currency for the economy of ancient Athens
Athens is one of the oldest named cities in the world, having been continuously inhabited for perhaps 5,000 years. Situated in southern Europe, Athens became the leading city of Ancient Greece in the first millennium BC, and its cultural achieve ...
, where the process involved mining the ore in underground galleries, washing and then smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a ch ...
it to produce the metal. Elaborate washing tables still exist at the site which used rain water held in cisterns and collected during the winter months.
The Romans took over silver mining in Spain from Carthage
Carthage was the capital city of Ancient Carthage, on the eastern side of the Lake of Tunis in what is now Tunisia. Carthage was one of the most important trading hubs of the Ancient Mediterranean and one of the most affluent cities of the classi ...
after their acquisition of Carthaginian territories there following the Second Punic War
The Second Punic War (218 to 201 BC) was the second of three wars fought between Carthage and Rome, the two main powers of the western Mediterranean in the 3rd century BC. For 17 years the two states struggled for supremacy, primarily in Ital ...
. Extraction of silver from lead ore was widespread in Roman Britain
Roman Britain was the period in classical antiquity when large parts of the island of Great Britain were under occupation by the Roman Empire. The occupation lasted from AD 43 to AD 410. During that time, the territory conquered was ...
very soon after the Roman conquest of the first century AD.
One of the main aims of the Viking
Vikings ; non, víkingr is the modern name given to seafaring people originally from Scandinavia (present-day Denmark, Norway and Sweden),
who from the late 8th to the late 11th centuries raided, pirated, traded and se ...
expansion throughout Europe was to acquire and trade silver. Bergen
Bergen (), historically Bjørgvin, is a city and municipality in Vestland county on the west coast of Norway. , its population is roughly 285,900. Bergen is the second-largest city in Norway. The municipality covers and is on the peninsula of ...
and Dublin
Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of th ...
are still important centres of silver making. An example of a collection of Viking-age silver for trading purposes is the Galloway Hoard.
From the mid-15th century silver began to be extracted from copper ores in massive quantities using the liquation
Liquation is a metallurgical method for separating metals from an ore or alloy. A mixture of metals is melted together with a third, after which the mixture is separated by liquid extraction. This method was largely used to separate silver from co ...
process creating a boost to the mining and metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the sc ...
industries of Central Europe
Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the area' ...
.
Americas
Vast amounts of silver were brought into the possession of the crowns of Europe after the conquest
Conquest is the act of military subjugation of an enemy by force of arms.
Military history provides many examples of conquest: the Roman conquest of Britain, the Mauryan conquest of Afghanistan and of vast areas of the Indian subcontinent, t ...
of the Americas
The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World.
Along with th ...
from the now Mexican state of Zacatecas
, image_map = Zacatecas in Mexico (location map scheme).svg
, map_caption = State of Zacatecas within Mexico
, coordinates =
, coor_pinpoint =
, coordinates_footnotes =
, subdivision_type ...
(discovered in 1546) and Potosí
Potosí, known as Villa Imperial de Potosí in the colonial period, is the capital city and a municipality of the Department of Potosí in Bolivia. It is one of the highest cities in the world at a nominal . For centuries, it was the location o ...
(Bolivia, also discovered in 1546), which triggered the Spanish Price Revolution in Europe. Silver mining required large amounts of mercury to extract the metal from ore. In the Andes, the source was the Huancavelica
Huancavelica () or Wankawillka in Quechua is a city in Peru. It is the capital of the department of Huancavelica and according to the 2017 census had a population of 49,570 people. The city was established on August 5, 1572 by the Viceroy ...
mercury mine; Mexico was dependent on mercury from the Almadén
Almadén () is a town and municipality in the Spanish province of Ciudad Real, within the autonomous community of Castile-La Mancha. The town is located at 4° 49' W and 38° 46' N and is 589 meters above sea level. Almadén is approximately 300 ...
mercury mine in Spain. Mercury had a high adverse environmental impact. Silver was extremely valuable in China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, and became a global commodity. Manila galleon
fil, Galyon ng Maynila
, english_name = Manila Galleon
, duration = From 1565 to 1815 (250 years)
, venue = Between Manila and Acapulco
, location = New Spain (Spanish Empire) ...
s carried Spanish dollar
The Spanish dollar, also known as the piece of eight ( es, Real de a ocho, , , or ), is a silver coin of approximately diameter worth eight Spanish reales. It was minted in the Spanish Empire following a monetary reform in 1497 with content ...
s across the Pacific, contributing to the rise of the Spanish Empire
The Spanish Empire ( es, link=no, Imperio español), also known as the Hispanic Monarchy ( es, link=no, Monarquía Hispánica) or the Catholic Monarchy ( es, link=no, Monarquía Católica) was a colonial empire governed by Spain and its prede ...
. The rise and fall of its value affected the world market.
In the first half of the 19th century Chilean mining revived due to a silver rush in the Norte Chico region, leading to an increased presence of Chileans in the Atacama desert and a shift away from an agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
based economy. The country of Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
was named after its silver resources by Spanish conquistadors; Argentina is a Spanish adjective meaning "silvery".
Silver mining was a driving force in the settlement of western North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, with major booms for silver and associated minerals (lead, mostly) in the galena
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Galena is one of the most abundant and widely distributed sulfide minerals. It cryst ...
ore silver is most commonly found in. Notable silver rush
A silver rush is the silver-mining equivalent of a gold rush, where the discovery of silver-bearing ore sparks a mass migration of individuals seeking wealth in the new mining region.
Notable silver rushes have taken place in Mexico, Chile, the U ...
es were in Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
; Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
; Cobalt, Ontario
Cobalt is a town in Timiskaming District, Ontario, Canada. It had a population of 1,118 at the 2016 Census.
In the early 1900s, the area was heavily mined for silver; the silver ore also contained cobalt. By 1910, the community was the fourth h ...
; California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
and the Kootenay
Kootenay, Kootenai, and Kutenai may refer to:
Ethnic groups
*The Kutenai, also known as the Ktunaxa, Kootenai, or Kootenay, an indigenous people of the United States and Canada
**Kutenai language, the traditional language of the Kutenai
**Ktunaxa ...
region of British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
; notably in the Boundary
Boundary or Boundaries may refer to:
* Border, in political geography
Entertainment
*Boundaries (2016 film), ''Boundaries'' (2016 film), a 2016 Canadian film
*Boundaries (2018 film), ''Boundaries'' (2018 film), a 2018 American-Canadian road trip ...
and "Silvery" Slocan. A silver rush in Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...
produced mines in an area known as Silver Valley, a handful of which are still active today. The first major silver ore deposits in the United States were discovered at the Comstock Lode
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada (then western Utah Territory), which was the first major discovery of silver ore in the United ...
in Virginia City, Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
, in 1859.
Environmental effects of historic silver mining
The amalgamation
Amalgamation is the process of combining or uniting multiple entities into one form.
Amalgamation, amalgam, and other derivatives may refer to:
Mathematics and science
* Amalgam (chemistry), the combination of mercury with another metal
**Pan am ...
methods have proven problematic. It is estimated that 90% of the mercury consumed 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 states, a federal district, five major unincorporated territorie ...
from 1850 to 1900 was used to extract silver and gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
.[Nriagu, Jerome, 1994. Mercury pollution from the past mining of gold and silver in the Americas. Science of the Total Environment, Volume 149, Issue 3, Pages 167-181,ISSN 0048-9697, https://doi.org/10.1016/0048-9697(94)90177-5.] An estimated 257,400 tonnes of mercury were lost to the environment in this process in the Americas since the patio process was first used. 60-65% of this is likely released into the atmosphere, being the single largest contributor to the global mercury cycle
The mercury cycle is a biogeochemical cycle influenced by natural and anthropogenic processes that transform mercury through multiple chemical forms and environments.
Mercury is present in the Earth's crust and in various forms on the Earth ...
.
Contaminants are also known to enter drinking water in and around abandoned silver mines. Well water in South Morelos State, Mexico, was found to have high concentrations of toxic metals including arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
, iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
, manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
, lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
, and fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...
.[Esteller, M.V., Domínguez-Mariani, E., Garrido, S.E. ''et al.'' Groundwater pollution by arsenic and other toxic elements in an abandoned silver mine, Mexico. ''Environ Earth Sci'' 74, 2893–2906 (2015). ] This is attributed to the abandoned and flooded silver mine at Huautla. Groundwaters flooded the mine-shafts after they were abandoned in the early 1990s, which allowed for oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
and mobilization of these dangerous contaminants.
See also
*Silver mining in the United States
Silver mining in the United States began on a major scale with the discovery of the Comstock Lode in Nevada in 1858. The industry suffered greatly from the demonetization of silver in 1873 by the Coinage Act of 1873, known pejoratively as the " Cr ...
*Economic history of Spain
This article covers the development of Spain's economy over the course of its history.
Ancient era
Iberians, roughly located in the South and East, and Celts in the North and West of the Iberian Peninsula were the major earliest groups in what ...
** Global silver trade from the 16th to 19th centuries
**Spanish Empire
The Spanish Empire ( es, link=no, Imperio español), also known as the Hispanic Monarchy ( es, link=no, Monarquía Hispánica) or the Catholic Monarchy ( es, link=no, Monarquía Católica) was a colonial empire governed by Spain and its prede ...
** Latin American economy
Latin America as a region has multiple nation-states, with varying levels of economic complexity. The Latin American economy is an export-based economy consisting of individual countries in the geographical regions of North America, Central Americ ...
** Spanish treasure fleet
The Spanish treasure fleet, or West Indies Fleet ( es, Flota de Indias, also called silver fleet or plate fleet; from the es, label=Spanish, plata meaning "silver"), was a convoy system of sea routes organized by the Spanish Empire from 1566 to ...
** Spanish Silver Train
** Royal fifth
The royal fifth (Spanish language, Spanish and pt, quinto real / quinto del rey) is an old royal tax that reserves to the monarch 20% of all precious metals and other commodities (including Slavery in medieval Europe, slaves) acquired by his sub ...
, 20% tax
** Patio process
The patio process is a process for extracting silver from ore. Smelting, or refining, was necessary because silver does not occur by itself in a natural state like some metals. Instead, it is made up of a larger ore body. Thus, smelting, or refin ...
, invented in Mexico
References
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