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Mining is the
extraction Extraction may refer to: Science and technology Biology and medicine * Comedo extraction, a method of acne treatment * Dental extraction, the surgical removal of a tooth from the mouth Computing and information science * Data extraction, the pr ...
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 An economy is an area of the production, distribution and trade, as well as consumption of goods and services. In general, it is defined as a social domain that emphasize the practices, discourses, and material expressions associated with th ...
viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones,
limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...
,
chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. C ...
, dimension stone, rock salt, potash, gravel, and
clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...
. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created
artificially Artificiality (the state of being artificial or manmade) is the state of being the product of intentional human manufacture, rather than occurring naturally through processes not involving or requiring human activity. Connotations Artificiality ...
in a
laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physi ...
or
factory A factory, manufacturing plant or a production plant is an industrial facility, often a complex consisting of several buildings filled with machinery, where workers manufacture items or operate machines which process each item into another. ...
. Mining in a wider sense includes extraction of any non-renewable resource such as
petroleum Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...
, natural gas, or even
water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, and final reclamation or restoration of the land after the mine is closed. Mining operations can create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the world's nations have passed regulations to decrease the impact; however, the outsized role of mining in generating business for often
rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are de ...
, remote or economically depressed communities means that governments may fail to fully enforce such regulations. Work safety has long been a concern as well, and where enforcing modern practices have significantly improved safety in mines. Moreover, unregulated or poorly regulated mining, especially in developing economies, frequently contributes to local human rights violations and resource conflicts.


History


Prehistory

Since the beginning of civilization, people have used stone,
clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...
and, later,
metal A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...
s found close to the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
's surface. These were used to make early
tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates b ...
s and weapons; for example, high quality flint found in northern
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
, southern
England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...
and
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 populou ...
was used to create flint tools. Flint mines have been found in
chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. C ...
areas where seams of the stone were followed underground by shafts and galleries. The mines at Grimes Graves and Krzemionki are especially famous, and like most other flint mines, are
Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several pa ...
in origin (c. 4000–3000 BC). Other hard rocks mined or collected for axes included the greenstone of the
Langdale axe industry The Langdale axe industry (or factory) is the name given by archaeologists to a Neolithic centre of specialised stone tool production in the Great Langdale area of the English Lake District. (For accompanying material seSupplement 1of same vo ...
based in the
English Lake District The Lake District, also known as the Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous for its lakes, forests, and mountains (or ''fells''), and its associations with William Wordsw ...
. The oldest-known mine on archaeological record is the
Ngwenya Mine The Ngwenya Mine is located on Bomvu Ridge, northwest of Mbabane and near the northwestern border of Eswatini (Swaziland). This mine is considered to be the world's oldest. The haematite ore deposit was used in the Middle Stone Age to extract red ...
in
Eswatini (Swaziland) Eswatini ( ; ss, eSwatini ), officially the Kingdom of Eswatini and formerly named Swaziland ( ; officially renamed in 2018), is a landlocked country in Southern Africa. It is bordered by Mozambique to its northeast and South Africa to its no ...
, which radiocarbon dating shows to be about 43,000 years old. At this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of a similar age in
Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
are believed to be sites where Neanderthals may have mined flint for weapons and tools.


Ancient Egypt

Ancient Egyptians mined
malachite Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fracture ...
at Maadi. At first, Egyptians used the bright green malachite stones for ornamentations and
pottery Pottery is the process and the products of forming vessels and other objects with clay and other ceramic materials, which are fired at high temperatures to give them a hard and durable form. Major types include earthenware, stoneware and ...
. Later, between 2613 and 2494 BC, large building projects required expeditions abroad to the area of
Wadi Maghareh Wadi Maghareh (also spelled Maghara or Magharah, meaning "The Valley of Caves" in Egyptian Arabic), is an archaeological site located in the southwestern Sinai Peninsula, Egypt. It contains pharaonic monuments and turquoise mines dating from ...
in order to secure minerals and other resources not available in Egypt itself.Shaw, I. (2000). ''The Oxford History of Ancient Egypt''. New York: Oxford University Press, p. 108. Quarries for turquoise and
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 pink ...
were also found at Wadi Hammamat, Tura, Aswan and various other
Nubia Nubia () ( Nobiin: Nobīn, ) is a region along the Nile river encompassing the area between the first cataract of the Nile (just south of Aswan in southern Egypt) and the confluence of the Blue and White Niles (in Khartoum in central Sud ...
n sites on the Sinai Peninsula and at Timna.
Mining in Egypt Mining in Egypt has had a long history that dates back to predynastic times. Active mining began in Egypt around 3000 BCE. Egypt has substantial mineral resources, including 48 million tons of tantalite (fourth largest in the world), 50  ...
occurred in the earliest dynasties. The gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one method used to break down the hard rock holding the
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 ...
. One of the complexes is shown in one of the earliest known maps. The miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust.


Ancient Greece and Rome

Mining in Europe has a very long history. Examples include the silver mines of Laurium, which helped support the Greek city state of
Athens Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates a ...
. Although they had over 20,000 slaves working them, their technology was essentially identical to their
Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...
predecessors. At other mines, such as on the island of Thassos, marble was quarried by the Parians after they arrived in the 7th century BC. The marble was shipped away and was later found by archaeologists to have been used in buildings including the tomb of Amphipolis. Philip II of Macedon, the father of
Alexander the Great Alexander III of Macedon ( grc, Ἀλέξανδρος, Alexandros; 20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great, was a king of the ancient Greek kingdom of Macedon. He succeeded his father Philip II to ...
, captured the gold mines of Mount Pangeo in 357 BC to fund his military campaigns. He also captured gold mines in Thrace for minting coinage, eventually producing 26
ton Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses. Mainly it describes units of weight. Confusion can arise because ''ton'' can mean * the long ton, which is 2,240 pounds ...
s per year. However, it was the Romans who developed large-scale mining methods, especially the use of large volumes of water brought to the minehead by numerous aqueducts. The water was used for a variety of purposes, including removing overburden and rock debris, called hydraulic mining, as well as washing
comminuted Comminuted may refer to: *Comminution, the process in which solid materials are reduced in size, by crushing, grinding and other processes *Bone fracture A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there ...
, or crushed, ores and driving simple machinery. The Romans used hydraulic mining methods on a large scale to prospect for the veins of ore, especially using a now-obsolete form of mining known as hushing. They built numerous aqueducts to supply water to the minehead, where the water was stored in large reservoirs and tanks. When a full tank was opened, the flood of water sluiced away the overburden to expose the bedrock underneath and any gold-bearing veins. The rock was then worked by fire-setting to heat the rock, which would be quenched with a stream of water. The resulting thermal shock cracked the rock, enabling it to be removed by further streams of water from the overhead tanks. The Roman miners used similar methods to work cassiterite deposits in Cornwall and lead ore in the Pennines. Sluicing methods were developed by the Romans in
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
in 25 AD to exploit large alluvial gold deposits, the largest site being at Las Medulas, where seven long aqueducts tapped local rivers and sluiced the deposits. The Romans also exploited the silver present in the argentiferous galena in the mines of Cartagena (''Cartago Nova''), Linares (''Castulo''), Plasenzuela and Azuaga, among many others.
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
was one of the most important mining regions, but all regions of the
Roman Empire The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Roman Republic, Republican period of ancient Rome. As a polity, it included large territorial holdings aro ...
were exploited. In
Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It ...
the natives had mined minerals for millennia, but after the Roman conquest, the scale of the operations increased dramatically, as the Romans needed
Britannia Britannia () is the national personification of Britain as a helmeted female warrior holding a trident and shield. An image first used in classical antiquity, the Latin ''Britannia'' was the name variously applied to the British Isles, Grea ...
's resources, especially
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 ...
,
silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
, tin, and lead. Roman techniques were not limited to surface mining. They followed the ore veins underground once opencast mining was no longer feasible. At Dolaucothi they stoped out the veins and drove adits through bare rock to drain the stopes. The same adits were also used to ventilate the workings, especially important when fire-setting was used. At other parts of the site, they penetrated the
water table The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. T ...
and dewatered the mines using several kinds of machines, especially
reverse overshot water-wheel Frequently used in mines and probably elsewhere (such as agricultural drainage), the reverse overshot water wheel was a Roman innovation to help remove water from the lowest levels of underground workings. It is described by Vitruvius in his work ' ...
s. These were used extensively in the
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 pink ...
mines at Rio Tinto in Spain, where one sequence comprised 16 such wheels arranged in pairs, and lifting water about . They were worked as treadmills with miners standing on the top slats. Many examples of such devices have been found in old Roman mines and some examples are now preserved in the
British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...
and the National Museum of Wales.


Medieval Europe

Mining as an industry underwent dramatic changes in medieval Europe. The mining industry in the early
Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
was mainly focused on the extraction 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 pink ...
and
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 ...
. Other precious metals were also used, mainly for gilding or coinage. Initially, many metals were obtained through open-pit mining, and ore was primarily extracted from shallow depths, rather than through deep mine shafts. Around the 14th century, the growing use of weapons, armour,
stirrup A stirrup is a light frame or ring that holds the foot of a rider, attached to the saddle by a strap, often called a ''stirrup leather''. Stirrups are usually paired and are used to aid in mounting and as a support while using a riding animal ...
s, and horseshoes greatly increased the demand for iron. Medieval knights, for example, were often laden with up to of plate or chain link armour in addition to swords,
lances A lance is a spear designed to be used by a mounted warrior or cavalry soldier (lancer). In ancient and medieval warfare, it evolved into the leading weapon in cavalry charges, and was unsuited for throwing or for repeated thrusting, unlike sim ...
and other weapons. The overwhelming dependency on iron for military purposes spurred iron production and extraction processes. The silver crisis of 1465 occurred when all mines had reached depths at which the shafts could no longer be pumped dry with the available technology. Although an increased use of banknotes, credit and
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 pink ...
coins during this period did decrease the value of, and dependence on, precious metals,
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 ...
and
silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
still remained vital to the story of medieval mining. Due to differences in the social structure of society, the increasing extraction of mineral deposits spread from
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 a ...
to England in the mid-sixteenth century. On the continent, mineral deposits belonged to the crown, and this regalian right was stoutly maintained. But in England, royal mining rights were restricted 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 ...
and
silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
(of which England had virtually no deposits) by a judicial decision of 1568 and a law in 1688.
England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...
had
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 ...
,
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 ...
,
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 pink ...
, lead, and tin ores.
Landlords A landlord is the owner of a house, apartment, condominium, land, or real estate which is rented or leased to an individual or business, who is called a tenant (also a ''lessee'' or ''renter''). When a juristic person is in this position, th ...
who owned the base metals and coal under their estates then had a strong inducement to extract these metals or to lease the deposits and collect royalties from mine operators. English,
German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...
, and Dutch
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used fo ...
combined to finance extraction and refining. Hundreds of German technicians and skilled workers were brought over; in 1642 a colony of 4,000 foreigners was mining and smelting copper at Keswick in the northwestern mountains. Use of water power in the form of water mills was extensive. The water mills were employed in crushing ore, raising ore from shafts, and ventilating galleries by powering giant bellows. Black powder was first used in mining in Selmecbánya,
Kingdom of Hungary The Kingdom of Hungary was a monarchy in Central Europe that existed for nearly a millennium, from the Middle Ages into the 20th century. The Principality of Hungary emerged as a Christian kingdom upon the Coronation of the Hungarian monarch, c ...
(now Banská Štiavnica, Slovakia) in 1627. Black powder allowed blasting of rock and earth to loosen and reveal ore veins. Blasting was much faster than fire-setting and allowed the mining of previously impenetrable metals and ores. In 1762, the world's first mining academy was established in the same town there. The widespread adoption of agricultural innovations such as the iron plowshare, as well as the growing use of metal as a building material, was also a driving force in the tremendous growth of the iron industry during this period. Inventions like the arrastra were often used by the Spanish to pulverize ore after being mined. This device was powered by animals and used the same principles used for grain threshing. Much of the knowledge of medieval mining techniques comes from books such as
Biringuccio Vannoccio Biringuccio, sometimes spelled Vannocio Biringuccio (c. 1480 – c. 1539), was an Italian metallurgist. He is best known for his manual on metalworking, ''De la pirotechnia'', published posthumously in 1540. 20th Century translation by ...
's '' De la pirotechnia'' and probably most importantly from
Georg Agricola Georgius Agricola (; born Georg Pawer or Georg Bauer; 24 March 1494 – 21 November 1555) was a German Humanist scholar, mineralogist and metallurgist. Born in the small town of Glauchau, in the Electorate of Saxony of the Holy Roman Empir ...
's '' De re metallica'' (1556). These books detail many different mining methods used in German and Saxon mines. A prime issue in medieval mines, which Agricola explains in detail, was the removal of water from mining shafts. As miners dug deeper to access new veins, flooding became a very real obstacle. The mining industry became dramatically more efficient and prosperous with the invention of mechanically- and animal-driven pumps.


Africa

Iron metallurgy in Africa The topic of early iron-metallurgy in Africa encompasses both studies of the technology and archaeology of indigenous iron-production. Some recent studies date the inception of iron metallurgy in Africa between 3000 and 2500 BCE. Evidence exi ...
dates back over four thousand years. Gold became an important commodity for Africa during the trans-Saharan gold trade from the 7th century to the 14th century. Gold was often traded to Mediterranean economies that demanded gold and could supply salt, even though much of Africa was abundant with salt due to the mines and resources in the Sahara desert. The trading of gold for salt was mostly used to promote trade between the different economies. Since the 19th century, gold and diamond mining in Southern Africa has had major political and economic impacts. The Democratic Republic of Congo is the largest producer of diamonds in Africa, with an estimated 12 million carats in 2019. Other types of mining reserves in Africa include cobalt, bauxite, iron ore, coal, and
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 pink ...
.


Oceania

Gold and coal mining started in Australia and New Zealand in the 19th century. Nickel has become important in the economy of New Caledonia. In
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consis ...
, in 1934, the Emperor Gold Mining Company Ltd. established operations at Vatukoula, followed in 1935 by the Loloma Gold Mines, N.L., and then by Fiji Mines Development Ltd. (aka Dolphin Mines Ltd.). These developments ushered in a “mining boom”, with gold production rising more than a hundred-fold, from 931.4 oz in 1934 to 107,788.5 oz in 1939, an order of magnitude then comparable to the combined output of New Zealand and Australia's eastern states.


Americas

During prehistoric times, early Americans mined large amounts 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 pink ...
along Lake Superior's Keweenaw Peninsula and in nearby Isle Royale; metallic copper was still present near the surface in colonial times.Lankton, L. (1991). ''Cradle to Grave: Life, Work, and Death at the Lake Superior Copper Mines''. New York: Oxford University Press, pp. 5–6.West, G.A. (1970). ''Copper: its mining and use by the aborigines of the Lake Superior Region''. Westport, Conn: Greenwood Press.Ricard, T. A. (1932), ''A History of American Mining'', McGraw-Hill Book Company. Indigenous peoples used Lake Superior copper from at least 5,000 years ago; copper tools, arrowheads, and other artifacts that were part of an extensive native trade-network have been discovered. In addition, obsidian, flint, and other minerals were mined, worked, and traded. Early French explorers who encountered the sites made no use of the metals due to the difficulties of transporting them, but the copper was eventually traded throughout the continent along major river routes. In the early colonial history of the Americas, "native gold and silver was quickly expropriated and sent back to Spain in fleets of gold- and silver-laden galleons", the gold and silver originating mostly from mines in Central and South America. Turquoise dated at 700 AD was mined in
pre-Columbian In the history of the Americas, the pre-Columbian era spans from the original settlement of North and South America in the Upper Paleolithic period through European colonization, which began with Christopher Columbus's voyage of 1492. Usually, ...
America; in the Cerillos Mining District in
New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...
, an estimate of "about 15,000 tons of rock had been removed from Mt. Chalchihuitl using
stone tool A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric (particularly Stone A ...
s before 1700." In 1727 Louis Denys (Denis) (1675–1741), sieur de La Ronde – brother of
Simon-Pierre Denys de Bonaventure Simon-Pierre Denys de Bonaventure (22 June 1659 – 7 February 1711) was born in Trois-Rivières, Québec to Pierre Denys de La Ronde and Catherine Le Neuf. He became an officer in the colonial troupes de la marine of New France and was he ...
and the son-in-law of René Chartier – took command of Fort La Pointe at
Chequamegon Bay Chequamegon Bay ( ) is an inlet of Lake Superior in Ashland and Bayfield counties in the extreme northern part of Wisconsin. History A Native American village, known as ''Chequamegon'', developed here in the mid-17th century. It was developed b ...
; where natives informed him of an island of copper. La Ronde obtained permission from the French crown to operate mines in 1733, becoming "the first practical miner on Lake Superior"; seven years later, mining was halted by an outbreak between Sioux and Chippewa tribes.
Mining in the United States Mining in the United States has been active since the beginning of colonial times, but became a major industry in the 19th century with a number of new mineral discoveries causing a series of mining rushes. In 2015, the value of coal, metals, and i ...
became widespread in the 19th century, and the United States Congress passed the
General Mining Act of 1872 The General Mining Act of 1872 is a United States federal law that authorizes and governs prospecting and mining for economic minerals, such as gold, platinum, and silver, on federal public lands. This law, approved on May 10, 1872, codified the ...
to encourage mining of federal lands. As with the California Gold Rush in the mid-19th century, mining for minerals and precious metals, along with ranching, became a driving factor in the U.S.
Westward Expansion The United States of America was created on July 4, 1776, with the U.S. Declaration of Independence of thirteen British colonies in North America. In the Lee Resolution two days prior, the colonies resolved that they were free and independent ...
to the Pacific coast. With the exploration of the West, mining camps sprang up and "expressed a distinctive spirit, an enduring legacy to the new nation"; Gold Rushers would experience the same problems as the Land Rushers of the transient West that preceded them. Aided by railroads, many people traveled West for work opportunities in mining. Western cities such as Denver and
Sacramento ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento ...
originated as mining towns. When new areas were explored, it was usually the gold ( placer and then lode) and then silver that were taken into possession and extracted first. Other metals would often wait for railroads or canals, as coarse gold dust and nuggets do not require smelting and are easy to identify and transport.


Modernity

In the early 20th century, the gold and silver rush to the western United States also stimulated mining for coal as well as base metals such as copper, lead, and iron. Areas in modern Montana, Utah, Arizona, and later Alaska became predominate suppliers of copper to the world, which was increasingly demanding copper for electrical and households goods.Miller C. (2013). ''Atlas of US and Canadian Environmental History''
p. 64
''Taylor & Francis''.
Canada's mining industry grew more slowly than did the United States' due to limitations in transportation, capital, and U.S. competition; Ontario was the major producer of the early 20th century with nickel, copper, and gold. Meanwhile, Australia experienced the Australian gold rushes and by the 1850s was producing 40% of the world's gold, followed by the establishment of large mines such as the
Mount Morgan Mine Mount Morgan Mine was a copper, gold and silver mine in Queensland, Australia. Mining began at Mount Morgan in 1882 and continued until 1981. Over its lifespan, the mine yielded approximately of gold, of silver and of copper. The mine was ...
, which ran for nearly a hundred years, Broken Hill ore deposit (one of the largest zinc-lead ore deposits), and the iron ore mines at Iron Knob. After declines in production, another boom in mining occurred in the 1960s. Now, in the early 21st century, Australia remains a major world mineral producer. As the 21st century begins, a globalized
mining industry 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 ...
of large multinational corporations has arisen.
Peak minerals Peak minerals marks the point in time when the largest production of a mineral will occur in an area, with production declining in subsequent years. While most mineral resources will not be exhausted in the near future, global extraction and pro ...
and environmental impacts have also become a concern. Different elements, particularly rare earth minerals, have begun to increase in demand as a result of new technologies.


Mine development and life cycle

The process of mining from discovery of an ore body through extraction of minerals and finally to returning the land to its natural state consists of several distinct steps. The first is discovery of the ore body, which is carried out through prospecting or exploration to find and then define the extent, location and value of the ore body. This leads to a mathematical resource estimation to estimate the size and grade of the deposit. This estimation is used to conduct a pre-feasibility study to determine the theoretical economics of the ore deposit. This identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work. The next step is to conduct a feasibility study to evaluate the financial viability, the technical and financial risks, and the robustness of the project. This is when the mining company makes the decision whether to develop the mine or to walk away from the project. This includes mine planning to evaluate the economically recoverable portion of the deposit, the metallurgy and ore recoverability, marketability and payability of the ore concentrates, engineering concerns, milling and infrastructure costs, finance and equity requirements, and an analysis of the proposed mine from the initial excavation all the way through to reclamation. The proportion of a deposit that is economically recoverable is dependent on the
enrichment factor Enrichment factor is used to describe bodies of mineral ore. It is defined as the minimum factor by which the weight percent of mineral in an orebody is greater than the average occurrence of that mineral in the Earth's crust. It can be used to comp ...
of the ore in the area. To gain access to the mineral deposit within an area it is often necessary to mine through or remove waste material which is not of immediate interest to the miner. The total movement of ore and waste constitutes the mining process. Often more waste than ore is mined during the life of a mine, depending on the nature and location of the ore body. Waste removal and placement is a major cost to the mining operator, so a detailed characterization of the waste material forms an essential part of the geological exploration program for a mining operation. Once the analysis determines a given ore body is worth recovering, development begins to create access to the ore body. The mine buildings and processing plants are built, and any necessary equipment is obtained. The operation of the mine to recover the ore begins and continues as long as the company operating the mine finds it economical to do so. Once all the ore that the mine can produce profitably is recovered, reclamation can begin, to make the land used by the mine suitable for future use. Technical and economic challenges notwithstanding, successful mine development must also address human factors. Working conditions are paramount to success, especially with regard to exposures to dusts, radiation, noise, explosives hazards, and vibration, as well as illumination standards. Mining today increasingly must address environmental and community impacts, including psychological and sociological dimensions. Thus, mining educator
Frank T. M. White Frank Thomas Matthews White (1909–1971) was an Australian mining and metallurgical engineer and mineral science educator. His career included appointments in Australia, Fiji, Malaya, and Canada. An examination of White's career reveals steady ...
(1909–1971), broadened the focus to the “total environment of mining”, including reference to community development around mining, and how mining is portrayed to an urban society, which depends on the industry, although seemingly unaware of this dependency. He stated, “ the past, mining engineers have not been called upon to study the psychological, sociological and personal problems of their own industry – aspects that nowadays are assuming tremendous importance. The mining engineer must rapidly expand his knowledge and his influence into these newer fields.”


Techniques

Mining techniques can be divided into two common
excavation Excavation may refer to: * Excavation (archaeology) * Excavation (medicine) * ''Excavation'' (The Haxan Cloak album), 2013 * ''Excavation'' (Ben Monder album), 2000 * ''Excavation'' (novel), a 2000 novel by James Rollins * '' Excavation: A Mem ...
types: surface mining and sub-surface (underground) mining. Today, surface mining is much more common, and produces, for example, 85% of minerals (excluding petroleum and natural gas) in the United States, including 98% of metallic ores. Targets are divided into two general categories of materials: ''placer deposits'', consisting of valuable minerals contained within river gravels, beach sands, and other unconsolidated materials; and ''lode deposits'', where valuable minerals are found in veins, in layers, or in mineral grains generally distributed throughout a mass of actual rock. Both types of ore deposit, placer or lode, are mined by both surface and underground methods. Some mining, including much of the rare earth elements and uranium mining, is done by less-common methods, such as in-situ leaching: this technique involves digging neither at the surface nor underground. The extraction of target minerals by this technique requires that they be soluble, e.g., potash, potassium chloride, sodium chloride, sodium sulfate, which dissolve in water. Some minerals, such as copper minerals and uranium oxide, require acid or carbonate solutions to dissolve.


Artisanal


Surface

Surface mining is done by removing surface vegetation, dirt, and bedrock to reach buried ore deposits. Techniques of surface mining include: open-pit mining, which is the recovery of materials from an open pit in the ground; quarrying, identical to open-pit mining except that it refers to sand, stone and clay; strip mining, which consists of stripping surface layers off to reveal ore underneath; and mountaintop removal, commonly associated with coal mining, which involves taking the top of a mountain off to reach ore deposits at depth. Most placer deposits, because they are shallowly buried, are mined by surface methods. Finally, landfill mining involves sites where landfills are excavated and processed. Landfill mining has been thought of as a long-term solution to methane emissions and local pollution.


High wall

High wall mining, which evolved from auger mining, is another form of surface mining. In high wall mining, the remaining part of a coal seam previously exploited by other surface-mining techniques has too much overburden to be removed but can still be profitably exploited from the side of the artificial cliff made by previous mining. A typical cycle alternates sumping, which undercuts the seam, and shearing, which raises and lowers the cutter-head boom to cut the entire height of the coal seam. As the coal recovery cycle continues, the cutter-head is progressively launched further into the coal seam. High wall mining can produce thousands of tons of coal in contour-strip operations with narrow benches, previously mined areas, trench mine applications and steep-dip seams.


Underground mining

Sub-surface mining consists of digging tunnels or shafts into the earth to reach buried ore deposits. Ore, for processing, and waste rock, for disposal, are brought to the surface through the tunnels and shafts. Sub-surface mining can be classified by the type of access shafts used, and the extraction method or the technique used to reach the mineral deposit. Drift mining uses horizontal access tunnels, slope mining uses diagonally sloping access shafts, and shaft mining uses vertical access shafts. Mining in hard and soft rock formations requires different techniques. Other methods include
shrinkage stope mining Stoping is the process of extracting the desired ore or other mineral from an underground mine, leaving behind an open space known as a stope. Stoping is used when the country rock is sufficiently strong not to collapse into the stope, although ...
, which is mining upward, creating a sloping underground room,
long wall mining Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically thick). The longwall panel (the block of coal that is being mined) is typically long (but can be upto long) and wide. Histor ...
, which is grinding a long ore surface underground, and room and pillar mining, which is removing ore from rooms while leaving pillars in place to support the roof of the room. Room and pillar mining often leads to retreat mining, in which supporting pillars are removed as miners retreat, allowing the room to cave in, thereby loosening more ore. Additional sub-surface mining methods include
hard rock mining Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the ...
, bore hole mining, drift and fill mining, long hole slope mining, sub level caving, and block caving.


Machines

Heavy machinery is used in mining to explore and develop sites, to remove and stockpile overburden, to break and remove rocks of various hardness and toughness, to process the ore, and to carry out reclamation projects after the mine is closed. Bulldozers, drills, explosives and trucks are all necessary for excavating the land. In the case of placer mining, unconsolidated gravel, or
alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. ...
, is fed into machinery consisting of a hopper and a shaking screen or
trommel A trommel screen, also known as a rotary screen, is a mechanical screening machine used to separate materials, mainly in the mineral and solid-waste processing industries.Stessel et al. 1996, pp. 558-568. It consists of a perforated cylindrical dr ...
which frees the desired minerals from the waste gravel. The minerals are then concentrated using sluices or jigs. Large drills are used to sink shafts, excavate stopes, and obtain samples for analysis.
Tram A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport ...
s are used to transport miners, minerals and waste. Lifts carry miners into and out of mines, and move rock and ore out, and machinery in and out, of underground mines. Huge trucks, shovels and cranes are employed in surface mining to move large quantities of overburden and ore. Processing plants use large crushers, mills, reactors, roasters and other equipment to consolidate the mineral-rich material and extract the desired compounds and metals from the ore.


Processing

Once the mineral is extracted, it is often then processed. The science of
extractive metallurgy Extractive metallurgy is a branch of metallurgical engineering wherein process and methods of extraction of metals from their natural mineral deposits are studied. The field is a materials science, covering all aspects of the types of ore, was ...
is a specialized area in the science of metallurgy that studies the extraction of valuable metals from their ores, especially through chemical or mechanical means. Mineral processing (or mineral dressing) is a specialized area in the science of metallurgy that studies the mechanical means of crushing, grinding, and washing that enable the separation (extractive metallurgy) of valuable metals or minerals from their gangue (waste material). Processing of placer ore material consists of gravity-dependent methods of separation, such as sluice boxes. Only minor shaking or washing may be necessary to disaggregate (unclump) the sands or gravels before processing. Processing of ore from a lode mine, whether it is a surface or subsurface mine, requires that the rock ore be crushed and pulverized before extraction of the valuable minerals begins. After lode ore is crushed, recovery of the valuable minerals is done by one, or a combination of several, mechanical and chemical techniques. Since most metals are present in ores as oxides or sulfides, the metal needs to be reduced to its metallic form. This can be accomplished through chemical means such as smelting or through electrolytic reduction, as in the case of
aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...
. Geometallurgy combines the geologic sciences with extractive metallurgy and mining. In 2018, led by Chemistry and Biochemistry professor Bradley D. Smith,
University of Notre Dame The University of Notre Dame du Lac, known simply as Notre Dame ( ) or ND, is a private Catholic research university in Notre Dame, Indiana, outside the city of South Bend. French priest Edward Sorin founded the school in 1842. The main c ...
researchers "invented a new class of molecules whose shape and size enable them to capture and contain precious metal ions," reported in a study published by the Journal of the American Chemical Society. The new method "converts gold-containing ore into
chloroauric acid Chloroauric acid is an inorganic compound with the chemical formula . It forms hydrates . Both the trihydrate and tetrahydrate are known. Both are orange-yellow solids consisting of the planar anion. Often chloroauric acid is handled as a soluti ...
and extracts it using an industrial solvent. The container molecules are able to selectively separate the gold from the solvent without the use of water stripping." The newly developed molecules can eliminate water stripping, whereas mining traditionally "relies on a 125-year-old method that treats gold-containing ore with large quantities of poisonous sodium cyanide... this new process has a milder environmental impact and that, besides gold, it can be used for capturing other metals such as platinum and palladium," and could also be used in urban mining processes that remove precious metals from wastewater streams.


Environmental effects


Environmental regulation

Mine operators frequently have to follow some regulatory practices to minimize environmental impact and avoid impacting human health. In better regulated economies, regulations require the common steps of environmental impact assessment, development of environmental management plans,
mine closure planning {{No footnotes, date=July 2009 Mine closure planning involves planning effectively for the after-mining landscape – all activities required before, during, and after the operating life of a mine that are needed to produce an acceptable landscape ...
(which must be done before the start of mining operations), and environmental monitoring during operation and after closure. However, in some areas, particularly in the developing world, government regulations may not be well enforced. For major mining companies and any company seeking international financing, there are a number of other mechanisms to enforce environmental standards. These generally relate to financing standards such as the Equator Principles, IFC environmental standards, and criteria for Socially responsible investing. Mining companies have used this oversight from the financial sector to argue for some level of industry self-regulation.Moody R. (2007). ''Rocks and Hard Places''. Zed Books. In 1992, a Draft Code of Conduct for Transnational Corporations was proposed at the Rio Earth Summit by the UN Centre for Transnational Corporations (UNCTC), but the Business Council for Sustainable Development (BCSD) together with the International Chamber of Commerce (ICC) argued successfully for self-regulation instead. This was followed by the Global Mining Initiative which was begun by nine of the largest metals and mining companies and which led to the formation of the International Council on Mining and Metals, whose purpose was to "act as a catalyst" in an effort to improve social and environmental performance in the mining and metals industry internationally. The mining industry has provided funding to various conservation groups, some of which have been working with conservation agendas that are at odds with an emerging acceptance of the rights of indigenous people – particularly the right to make land-use decisions. Certification of mines with good practices occurs through the
International Organization for Standardization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in A ...
(ISO). For example, ISO 9000 and ISO 14001, which certify an "auditable environmental management system", involve short inspections, although they have been accused of lacking rigor. Certification is also available through Ceres' Global Reporting Initiative, but these reports are voluntary and unverified. Miscellaneous other certification programs exist for various projects, typically through nonprofit groups. The purpose of a 2012 EPS PEAKS paper was to provide evidence on policies managing ecological costs and maximize
socio-economic Socioeconomics (also known as social economics) is the social science that studies how economic activity affects and is shaped by social processes. In general it analyzes how modern societies progress, stagnate, or regress because of their loc ...
benefits of mining using host country regulatory initiatives. It found existing literature suggesting donors encourage developing countries to: * Make the environment-poverty link and introduce cutting-edge wealth measures and natural capital accounts. * Reform old taxes in line with more recent financial innovation, engage directly with the companies, enact land use and impact assessments, and incorporate specialized support and standards agencies. * Set in play transparency and community participation initiatives using the wealth accrued.


Waste

Ore mills generate large amounts of waste, called
tailings In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction ( gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that ove ...
. For example, 99 tons of waste is generated per ton of copper, with even higher ratios in gold mining – because only 5.3 g of gold is extracted per ton of ore, a ton of gold produces 200,000 tons of tailings. (As time goes on and richer deposits are exhausted – and technology improves – this number is going down to .5 g and less.) These tailings can be toxic. Tailings, which are usually produced as a slurry, are most commonly dumped into ponds made from naturally existing valleys.US EPA. (1994)
Technical Report: Design and Evaluation of Tailings Dams
These ponds are secured by impoundments ( dams or embankment dams). In 2000 it was estimated that 3,500 tailings impoundments existed, and that every year, 2 to 5 major failures and 35 minor failures occurred. For example, in the
Marcopper mining disaster The Marcopper mining disaster is one of the worst mining and environmental disasters in Philippine history. It occurred on March 24, 1996, on the Philippine island of Marinduque, a province of the Philippines located in the Mimaropa region. The di ...
at least 2 million tons of tailings were released into a local river.TE Martin, MP Davies. (2000)
Trends in the stewardship of tailings dams
In 2015, Barrick Gold Corporation spilled over 1 million liters of
cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
into a total of five rivers in Argentina near their
Veladero mine The Veladero mine is a gold mine in Argentina. The mine is located in the north-western part of Argentina in San Juan Province. The mine has estimated reserves of 10 million oz of gold. It is operated by Barrick Gold Barrick Gold Corporation ...
. Since 2007 in central Finland, the Talvivaara Terrafame polymetal mine's waste effluent and leaks of saline mine water have resulted in ecological collapse of a nearby lake. Subaqueous tailings disposal is another option. The mining industry has argued that submarine tailings disposal (STD), which disposes of tailings in the sea, is ideal because it avoids the risks of tailings ponds. The practice is illegal in the United States and Canada, but it is used in the developing world. The waste is classified as either sterile or mineralized, with acid generating potential, and the movement and storage of this material form a major part of the mine planning process. When the mineralised package is determined by an economic cut-off, the near-grade mineralised waste is usually dumped separately with view to later treatment should market conditions change and it becomes economically viable. Civil engineering design parameters are used in the design of the waste dumps, and special conditions apply to high-rainfall areas and to seismically active areas. Waste dump designs must meet all regulatory requirements of the country in whose jurisdiction the mine is located. It is also common practice to rehabilitate dumps to an internationally acceptable standard, which in some cases means that higher standards than the local regulatory standard are applied.


Industry

Mining exists in many countries.
London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
is the headquarters for large miners such as Anglo American, BHP and Rio Tinto.MacDonald A. (2002)
Industry in Transition: A Profile of the North American Mining Sector

Free full-text
The US mining industry is also large, but it is dominated by extraction of coal and other nonmetal minerals (e.g., rock and sand), and various regulations have worked to reduce the significance of mining in the United States. In 2007, the total market capitalization of mining companies was reported at US$962 billion, which compares to a total global market cap of publicly traded companies of about US$50 trillion in 2007. In 2002, Chile and Peru were reportedly the major mining countries of
South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...
. The mineral industry of Africa includes the mining of various minerals; it produces relatively little of the industrial metals copper, lead, and zinc, but according to one estimate has as a percent of world reserves 40% of gold, 60% of cobalt, and 90% of the world's platinum group metals.
Mining in India The mining industry in India is a major economic activity which contributes significantly to the economy of India. The GDP contribution of the mining industry varies from 2.2% to 2.5% only but going by the GDP of the total industrial sector it ...
is a significant part of that country's economy. In the developed world, mining in Australia, with BHP founded and headquartered in the country, and mining in Canada are particularly significant. For rare earth minerals mining, China reportedly controlled 95% of production in 2013. While exploration and mining can be conducted by individual entrepreneurs or small businesses, most modern-day mines are large enterprises requiring large amounts of capital to establish. Consequently, the mining sector of the industry is dominated by large, often multinational, companies, most of them publicly listed. It can be argued that what is referred to as the 'mining industry' is actually two sectors, one specializing in exploration for new resources and the other in mining those resources. The exploration sector is typically made up of individuals and small mineral resource companies, called "juniors", which are dependent on venture capital. The mining sector is made up of large multinational companies that are sustained by production from their mining operations. Various other industries such as equipment manufacture, environmental testing, and metallurgy analysis rely on, and support, the mining industry throughout the world. Canadian stock exchanges have a particular focus on mining companies, particularly junior exploration companies through Toronto's TSX Venture Exchange; Canadian companies raise capital on these exchanges and then invest the money in exploration globally. Some have argued that below juniors there exists a substantial sector of illegitimate companies primarily focused on manipulating stock prices. Mining operations can be grouped into five major categories in terms of their respective resources. These are oil and gas extraction, coal mining, metal ore mining, nonmetallic mineral mining and quarrying, and mining support activities. Of all of these categories, oil and gas extraction remains one of the largest in terms of its global economic importance. Prospecting potential mining sites, a vital area of concern for the mining industry, is now done using sophisticated new technologies such as seismic prospecting and remote-sensing satellites. Mining is heavily affected by the prices of the commodity minerals, which are often volatile. The 2000s commodities boom ("commodities supercycle") increased the prices of commodities, driving aggressive mining. In addition, the price of gold increased dramatically in the 2000s, which increased gold mining; for example, one study found that conversion of forest in the Amazon increased six-fold from the period 2003–2006 (292 ha/yr) to the period 2006–2009 (1,915 ha/yr), largely due to artisanal mining.


Corporate classifications

Mining companies can be classified based on their size and financial capabilities: * ''Major'' companies are considered to have an adjusted annual mining-related revenue of more than US$500 million, with the financial capability to develop a major mine on its own. * ''Intermediate'' companies have at least $50 million in annual revenue but less than $500 million. * ''Junior'' companies rely on
equity Equity may refer to: Finance, accounting and ownership *Equity (finance), ownership of assets that have liabilities attached to them ** Stock, equity based on original contributions of cash or other value to a business ** Home equity, the diff ...
financing as their principal means of funding exploration. Juniors are mainly pure exploration companies, but may also produce minimally, and do not have a revenue exceeding US$50 million. Re their valuation, and stock market characteristics, see .


Regulation and governance

New regulations and a process of legislative reforms aim to improve the harmonization and stability of the mining sector in mineral-rich countries. New legislation for mining industry in African countries still appears to be an issue, but has the potential to be solved, when a consensus is reached on the best approach. By the beginning of the 21st century, the booming and increasingly complex mining sector in mineral-rich countries was providing only slight benefits to local communities, especially in given the sustainability issues. Increasing debate and influence by NGOs and local communities called for new approaches which would also include disadvantaged communities, and work towards
sustainable development Sustainable development is an organizing principle for meeting human development goals while also sustaining the ability of natural systems to provide the natural resources and ecosystem services on which the economy and society depend. The ...
even after
mine closure Mine closure is the period of time when the ore-extracting activities of a mine have ceased, and final decommissioning and mine reclamation are being completed. It is generally associated with reduced employment levels, which can have a significa ...
(including transparency and revenue management). By the early 2000s, community development issues and resettlements became mainstream concerns in World Bank mining projects. Mining-industry expansion after mineral prices increased in 2003 and also potential fiscal revenues in those countries created an omission in the other economic sectors in terms of finances and development. Furthermore, this highlighted regional and local demand for mining revenues and an inability of sub-national governments to effectively use the revenues. The
Fraser Institute The Fraser Institute is a libertarian-conservative Canadian public policy think tank and registered charity. The institute describes itself as independent and non-partisan. It is headquartered in Vancouver, with additional offices in Calgary, ...
(a Canadian think tank) has highlighted the environmental protection laws in developing countries, as well as voluntary efforts by mining companies to improve their environmental impact. In 2007, the Extractive Industries Transparency Initiative (EITI) was mainstreamed in all countries cooperating with the World Bank in mining industry reform. The EITI operates and was implemented with the support of the EITI multi-donor trust fund, managed by the World Bank. The EITI aims to increase transparency in transactions between governments and companies in extractive industries by monitoring the revenues and benefits between industries and recipient governments. The entrance process is voluntary for each country and is monitored by multiple stakeholders including governments, private companies and civil society representatives, responsible for disclosure and dissemination of the reconciliation report; however, the competitive disadvantage of company-by-company public report is for some of the businesses in Ghana at least, the main constraint. Therefore, the outcome assessment in terms of failure or success of the new EITI regulation does not only "rest on the government's shoulders" but also on civil society and companies. However, implementation has issues; inclusion or exclusion of
artisanal mining An artisanal miner or small-scale miner (ASM) is a subsistence miner who is not officially employed by a mining company, but works independently, mining minerals using their own resources, usually by hand. Small-scale mining includes enterprises ...
and small-scale mining (ASM) from the EITI and how to deal with "non-cash" payments made by companies to subnational governments. Furthermore, the disproportionate revenues the mining industry can bring to the comparatively small number of people that it employs, causes other problems, like a lack of investment in other less lucrative sectors, leading to swings in government revenue because of volatility in the oil markets. Artisanal mining is clearly an issue in EITI Countries such as the Central African Republic, D.R. Congo, Guinea, Liberia and Sierra Leone – i.e. almost half of the mining countries implementing the EITI. Among other things, limited scope of the EITI involving disparity in terms of knowledge of the industry and negotiation skills, thus far flexibility of the policy (e.g. liberty of the countries to expand beyond the minimum requirements and adapt it to their needs), creates another risk of unsuccessful implementation. Public awareness increase, where government should act as a bridge between public and initiative for a successful outcome of the policy is an important element to be considered.


World Bank

The World Bank has been involved in mining since 1955, mainly through grants from its International Bank for Reconstruction and Development, with the Bank's Multilateral Investment Guarantee Agency offering political risk insurance. Between 1955 and 1990 it provided about $2 billion to fifty mining projects, broadly categorized as reform and rehabilitation, greenfield mine construction, mineral processing, technical assistance, and engineering. These projects have been criticized, particularly the Ferro Carajas project of Brazil, begun in 1981. The World Bank established mining codes intended to increase foreign investment; in 1988, it solicited feedback from 45 mining companies on how to increase their involvement. In 1992, the World Bank began to push for privatization of government-owned mining companies with a new set of codes, beginning with its report ''The Strategy for African Mining''. In 1997, Latin America's largest miner Companhia Vale do Rio Doce (CVRD) was privatized. These and other developments, such as the Philippines 1995 Mining Act, led the bank to publish a third report (''Assistance for Minerals Sector Development and Reform in Member Countries'') which endorsed mandatory environment impact assessments and attention to the concerns of the local population. The codes based on this report are influential in the legislation of developing nations. The new codes are intended to encourage development through tax holidays, zero custom duties, reduced income taxes, and related measures. The results of these codes were analyzed by a group from the University of Quebec, which concluded that the codes promote foreign investment but "fall very short of permitting sustainable development". The observed negative correlation between natural resources and economic development is known as the resource curse.


Safety

Safety has long been a concern in the mining business, especially in sub-surface mining. The Courrières mine disaster, Europe's worst mining accident, involved the death of 1,099 miners in Northern
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
on March 10, 1906. This disaster was surpassed only by the Benxihu Colliery accident in
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
on April 26, 1942, which killed 1,549 miners. While mining today is substantially safer than it was in previous decades, mining accidents still occur. Government figures indicate that 5,000 Chinese miners die in accidents each year, while other reports have suggested a figure as high as 20,000. Mining accidents continue worldwide, including accidents causing dozens of fatalities at a time such as the 2007 Ulyanovskaya Mine disaster in Russia, the
2009 Heilongjiang mine explosion The 2009 Heilongjiang mine explosion () was a mining accident that occurred on November 21 2009, near Hegang in the Heilongjiang province, northeastern China, which killed 108 people. A further of 29 people were hospitalised. The explosion occurr ...
in China, and the 2010 Upper Big Branch Mine disaster in the United States. Mining has been identified by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector in the
National Occupational Research Agenda The National Occupational Research Agenda (NORA) is a partnership program developed by the National Institute for Occupational Safety and Health (NIOSH). The program was founded in 1996 to provide a framework for research collaborations among univer ...
(NORA) to identify and provide intervention strategies regarding occupational health and safety issues. The Mining Safety and Health Administration (MSHA) was established in 1978 to "work to prevent death, illness, and injury from mining and promote safe and healthful workplaces for US miners." Since its implementation in 1978, the number of miner fatalities has decreased from 242 miners in 1978 to 24 miners in 2019. There are numerous occupational hazards associated with mining, including exposure to rockdust which can lead to diseases such as silicosis,
asbestosis Asbestosis is long-term inflammation and scarring of the lungs due to asbestos fibers. Symptoms may include shortness of breath, cough, wheezing, and chest tightness. Complications may include lung cancer, mesothelioma, and pulmonary heart ...
, and pneumoconiosis. Gases in the mine can lead to asphyxiation and could also be ignited. Mining equipment can generate considerable noise, putting workers at risk for
hearing loss Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken l ...
. Cave-ins, rock falls, and exposure to excess heat are also known hazards. The current NIOSH Recommended Exposure Limit (REL) of noise is 85 dBA with a 3 dBA exchange rate and the MSHA Permissible Exposure Limit (PEL) is 90 dBA with a 5 dBA exchange rate as an 8-hour time-weighted average. NIOSH has found that 25% of noise-exposed workers in Mining, Quarrying, and Oil and Gas Extraction have hearing impairment. The prevalence of hearing loss increased by 1% from 1991 to 2001 within these workers. Noise studies have been conducted in several mining environments. Stageloaders (84-102 dBA), shearers (85-99 dBA), auxiliary fans (84–120 dBA), continuous mining machines (78–109 dBA), and roof bolters (92–103 dBA) represent some of the noisiest equipment in underground
coal mines Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron fro ...
.
Dragline A dragline excavator is a piece of heavy equipment used in civil engineering and surface mining. Draglines fall into two broad categories: those that are based on standard, lifting cranes, and the heavy units which have to be built on-site. ...
oilers, dozer operators, and welders using air arcing were occupations with the highest noise exposures among surface coal miners. Coal mines had the highest hearing loss injury likelihood.


Human rights

In addition to the environmental impacts of mining processes, a prominent criticism pertaining to this form of extractive practice and of mining companies are the human rights abuses occurring within mining sites and communities close to them. Frequently, despite being protected by International Labor rights, miners are not given appropriate equipment to provide them with protection from possible mine collapse or from harmful pollutants and chemicals expelled during the mining process, work in inhumane conditions spending numerous hours working in extreme heat, darkness and 14 hour workdays with no allocated time for breaks.


Child labor

Included within the human rights abuses that occur during mining processes are instances of child labor. These instances are a cause for widespread criticism of mines harvesting cobalt, a mineral essential for powering modern technologies such as laptops, smartphones and electric vehicles. Many of these cases of child laborers are found in the Democratic Republic of Congo. Reports have risen of children carrying sacks of cobalt weighing 25 kg from small mines to local traders being paid for their work only in food and accommodation. A number of companies such as
Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...
,
Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...
, Microsoft and Tesla have been implicated in lawsuits brought by families whose children were severely injured or killed during mining activities in Congo. In December 2019, 14 Congolese families filed a lawsuit against Glencore, a mining company which supplies the essential cobalt to these multinational corporations with allegations of negligence that led to the deaths of children or injuries such as broken spines, emotional distress and forced labor.


Indigenous peoples

There have also been instances of killings and evictions attributed to conflicts with mining companies. Almost a third of 227 murders in 2020 were of Indigenous peoples rights activists on the frontlines of
climate change activism The climate movement is a global social movement focused on pressuring governments and industry to take action (also called "climate action") addressing the causes and impacts of climate change. Environmental non-profit organizations have enga ...
linked to logging, mining, large-scale agribusiness, hydroelectric dams, and other infrastructure, according to
Global Witness Global Witness is an international NGO established in 1993 that works to break the links between natural resource exploitation, conflict, poverty, corruption, and human rights abuses worldwide. The organisation has offices in London and Washin ...
. The relationship between indigenous peoples and mining is defined by struggles over access to land. In Australia, the Aboriginal Bininj said mining posed a threat to their living culture and could damage sacred heritage sites. In the Philippines, an anti-mining movement has raised concerns regarding "the total disregard for ndigenous communities'ancestral land rights". Ifugao peoples' opposition to mining led a governor to proclaim a ban on mining operations in Mountain Province, Philippines. In Brazil, more than 170 tribes organized a march to oppose controversial attempts to strip back indigenous land rights and open their territories to mining operations. The United Nations Commission on Human Rights has called on Brazil's Supreme Court to uphold Indigenous land rights to prevent exploitation by mining groups and industrial agriculture.


Records

As of 2019,
Mponeng Mponeng is a gold mine in South Africa's Gauteng province. Previously known as Western Deep Levels #1 Shaft, the underground and surface works were commissioned in 1987. It extends over below the surface,. and is considered to be one of the most ...
is the world's deepest mine from ground level, reaching a depth of 4 km (2.5 mi) below ground level. The trip from the surface to the bottom of the mine takes over an hour. It is a gold mine in
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
's
Gauteng Gauteng ( ) is one of the nine provinces of South Africa. The name in Sotho-Tswana languages means 'place of gold'. Situated on the Highveld, Gauteng is the smallest province by land area in South Africa. Although Gauteng accounts for only ...
province. Previously known as
Western Deep Levels The TauTona Mine or Western Deep No.3 Shaft, was a gold mine in South Africa. At approximately deep, it was home to the world's second deepest mining operation, rivalled only by the Mponeng Gold Mine, but was closed in 2018. The mine was on ...
#1 Shaft, the underground and surface works were commissioned in 1987. The mine is considered to be one of the most substantial gold mines in the world. The Moab Khutsong gold mine in
North West Province (South Africa) North West is a province of South Africa. Its capital is Mahikeng. The province is located to the west of the major population centre of Gauteng and south of Botswana. History North West was incorporated after the end of Apartheid in 1994, ...
has the world's longest winding steel wire rope, which is able to lower workers to in one uninterrupted four-minute journey. The deepest mine in Europe is the 16th shaft of the uranium mines in Příbram,
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, at . Second is Bergwerk Saar in
Saarland The Saarland (, ; french: Sarre ) is a state of Germany in the south west of the country. With an area of and population of 990,509 in 2018, it is the smallest German state in area apart from the city-states of Berlin, Bremen, and Hamburg, a ...
,
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...
, at . The deepest open-pit mine in the world is Bingham Canyon Mine in
Bingham Canyon The Bingham Canyon Mine, more commonly known as Kennecott Copper Mine among locals, is an open-pit mining operation extracting a large porphyry copper deposit southwest of Salt Lake City, Utah, in the Oquirrh Mountains. The mine is the largest m ...
, Utah,
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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
, at over . The largest and second deepest open-pit copper mine in the world is
Chuquicamata Chuquicamata ( ; referred to as Chuqui for short) is the largest open pit copper mine in terms of excavated volume in the world. It is located in the north of Chile, just outside Calama, at above sea level. It is northeast of Antofagasta and ...
in northern
Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...
at , which annually produces 443,000 tons of copper and 20,000 tons of molybdenum. The deepest open-pit mine with respect to sea level is Tagebau Hambach in Germany, where the base of the pit is below sea level. The largest underground mine is Kiirunavaara Mine in Kiruna,
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...
. With of roads, 40 million tonnes of annually produced ore, and a depth of , it is also one of the most modern underground mines. The deepest borehole in the world is Kola Superdeep Borehole at , but this is connected to
scientific drilling Scientific drilling into the Earth is a way for scientists to probe the Earth's sediments, crust, and upper mantle. In addition to rock samples, drilling technology can unearth samples of connate fluids and of the subsurface biosphere, mostly micr ...
, not mining.


Metal reserves and recycling

During the 20th century, the variety of metals used in society grew rapidly. Today, the development of major nations such as China and India and advances in technologies are fueling an ever-greater demand. The result is that metal mining activities are expanding and more and more of the world's metal stocks are above ground in use rather than below ground as unused reserves. An example is the in-use stock 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 pink ...
. Between 1932 and 1999, copper in use in the US rose from to per person.''The Recycling Rates of Metals: A Status Report''
2010, International Resource Panel, United Nations Environment Programme
95% of the energy used to make aluminium from bauxite ore is saved by using recycled material. However, levels of metals recycling are generally low. In 2010, the International Resource Panel, hosted by the United Nations Environment Programme (UNEP), published reports on metal stocks that exist within society and their recycling rates. The report's authors observed that the metal stocks in society can serve as huge mines above ground. However, they warned that the recycling rates of some rare metals used in applications such as mobile phones, battery packs for hybrid cars, and fuel cells are so low that unless future end-of-life recycling rates are dramatically stepped up these critical metals will become unavailable for use in modern technology. As recycling rates are low and so much metal has already been extracted, some landfills now contain higher concentrations of metal than mines themselves. This is especially true of aluminium, used in cans, and precious metals, found in discarded electronics. Furthermore, waste after 15 years has still not broken down, so less processing would be required when compared to mining ores. A study undertaken by Cranfield University has found £360 million of metals could be mined from just four landfill sites. There is also up to 20 MJ/kg of energy in waste, potentially making the re-extraction more profitable. However, although the first landfill mine opened in
Tel Aviv Tel Aviv-Yafo ( he, תֵּל־אָבִיב-יָפוֹ, translit=Tēl-ʾĀvīv-Yāfō ; ar, تَلّ أَبِيب – يَافَا, translit=Tall ʾAbīb-Yāfā, links=no), often referred to as just Tel Aviv, is the most populous city in the G ...
, Israel in 1953, little work has followed due to the abundance of accessible ores.


See also


References


Further reading

* Woytinsky, W.S., and E.S. Woytinsky (1953). ''World Population and Production Trends and Outlooks'', pp. 749–881; with many tables and maps on the worldwide mining industry in 1950, including coal, metals and minerals * Ali, Saleem H. (2003). ''Mining, the Environment and Indigenous Development Conflicts''. Tucson AZ: University of Arizona Press. * Ali, Saleem H. (2009). ''Treasures of the Earth: need, greed and a sustainable future''. New Haven and London: Yale University Press. * * Geobacter Project
Gold mines may owe their origins to bacteria
(in PDF format) * Garrett, Dennis. ''Alaska Placer Mining''. * * Morrison, Tom (1992). ''Hardrock Gold: a miner's tale''. * John Milne. ''The Miner's Handbook: A Handy Reference on the subjects of Mineral Deposits (1894) Mining operations in the 19th century.'
The Miner's Handbook: A Handy Book of Reference on the Subjects of Mineral Deposits, Mining Operations, Ore Dressing, Etc. For the Use of Students and Others Interested in Mining Matters
* Aryee, B., Ntibery, B., Atorkui, E. (2003). "Trends in the small-scale mining of precious minerals in Ghana: a perspective on its environmental impact", ''Journal of Cleaner Production'' 11: 131–40. * Temple, John (1972).
Mining: An International History
'. Ernest Benn Limited. * The Oil, gas and Mining Sustainable Community Development Fund (2009). ''Social Mine Closure Strategy, Mali'' (i
CommDev: Projects: Social Mine Closure Strategy, Mali
. * White F. (2020). ''Miner with a Heart of Gold: biography of a mineral science and engineering educator.'' Friesen Press, Victoria. ISBN 978-1-5255-7765-9 (Hardcover), 978-1-5255-7766-6 (Paperback), 978-1-5255-7767-3 (eBook).


External links


First chapter
o
Introductory Mining Engineering

An introduction to geology and hard rock mining(archive)
* {{Authority control * Occupational safety and health Articles containing video clips