Misplaced Pages

#876123

74-569: Following development of high grade direct shipping iron ore deposits on the Mesabi Range , containing up to 65% iron and as little as 1.25% silica , miners termed the unaltered iron-formation wall rock taconite. The iron content of taconite is generally 30% to 35%, and the silica content generally around 45%. Iron in taconite is commonly present as magnetite, iron silicates, and iron-bearing carbonates, and locally martite (hematite) formed by oxidation of magnetite. Horizons containing magnetite as

148-528: A 33% to 40% recovery of magnetite by weight, to produce a concentrate grading in excess of 64% iron by weight. The typical magnetite iron ore concentrate has less than 0.1% phosphorus , 3–7% silica , and less than 3% aluminium . As of 2019, magnetite iron ore is mined in Minnesota and Michigan in the United States , eastern Canada , and northern Sweden . Magnetite-bearing banded iron formation

222-696: A benchmark to be followed by the rest of the industry. Singapore Mercantile Exchange (SMX) has launched the world's first global iron ore futures contract, based on the Metal Bulletin Iron Ore Index (MBIOI) which uses daily price data from a broad spectrum of industry participants and independent Chinese steel consultancy and data provider Shanghai Steelhome's widespread contact base of steel producers and iron ore traders across China. The futures contract has seen monthly volumes over 1,500,000 t (1,500,000 long tons; 1,700,000 short tons) after eight months of trading. This move follows

296-484: A blast furnace more efficient. Others are added because they make the iron more fluid, harder, or give it some other desirable quality. The choice of ore, fuel, and flux determines how the slag behaves and the operational characteristics of the iron produced. Ideally, iron ore contains only iron and oxygen. In reality, this is rarely the case. Typically, iron ore contains a host of elements which are often unwanted in modern steel. Silver Bay, Minnesota Silver Bay

370-650: A household in the city was $ 36,524, and the median income for a family was $ 41,667. Males had a median income of $ 40,655 versus $ 25,809 for females. The per capita income for the city was $ 16,958. About 5.3% of families and 6.8% of the population were below the poverty line , including 8.5% of those under age 18 and 2.9% of those age 65 or over. Silver Bay was served by the Silver Bay Municipal Airport until it closed on June 7, 2018, for an indefinite amount of time. Outer Drive (County Road 5), Penn Boulevard, and Minnesota Highway 61 are three of

444-424: A premium price. Due to the high density of hematite relative to associated silicate gangue, hematite beneficiation usually involves a combination of beneficiation techniques. One method relies on passing the finely-crushed ore over a slurry containing magnetite or other agent such as ferrosilicon which increases its density. When the density of the slurry is properly calibrated, the hematite will sink and

518-453: A relatively low-grade ore, they are also inexpensive to collect, as they do not have to be mined. Because of this, companies such as Magnetation have started reclamation projects where they use iron ore tailings as a source of metallic iron. The two main methods of recycling iron from iron ore tailings are magnetizing roasting and direct reduction. Magnetizing roasting uses temperatures between 700 and 900 °C (1,292 and 1,652 °F) for

592-616: A source of iron ore. Prior to the industrial revolution, most iron was obtained from widely-available goethite or bog ore , for example, during the American Revolution and the Napoleonic Wars . Historically, much of the iron ore utilized by industrialized societies has been mined from predominantly hematite deposits with grades of around 70% Fe. These deposits are commonly referred to as "direct shipping ores" or "natural ores". Increasing iron ore demand, coupled with

666-606: A switch to index-based quarterly pricing by the world's three largest iron ore miners— Vale , Rio Tinto , and BHP —in early 2010, breaking a 40-year tradition of benchmark annual pricing. Iron is the most abundant element on earth but not in the crust. The extent of the accessible iron ore reserves is not known, though Lester Brown of the Worldwatch Institute suggested in 2006 that iron ore could run out within 64 years (that is, by 2070), based on 2% growth in demand per year. Geoscience Australia calculates that

740-418: A time of under 1 hour to produce an iron concentrate (Fe 3 O 4 ) to be used for iron smelting. For magnetizing roasting, it is important to have a reducing atmosphere to prevent oxidization and the formation of Fe 2 O 3 because it is harder to separate as it is less magnetic. Direct reduction uses hotter temperatures of over 1,000 °C (1,830 °F) and longer times of 2–5 hours. Direct reduction

814-655: A typically titanium -bearing magnetite, often with vanadium . These ores form a niche market, with specialty smelters used to recover the iron, titanium, and vanadium. These ores are beneficiated essentially similarly to banded iron formation ores, but usually are more easily upgraded via crushing and screening . The typical titanomagnetite concentrate grades 57% Fe, 12% Ti, and 0.5% V 2 O 5 . For every one ton of iron ore concentrate produced, approximately 2.5–3.0 tons of iron ore tailings will be discharged. Statistics show that there are 130 million tons of iron ore tailings discharged every year. If, for example,

SECTION 10

#1732802466877

888-659: A value of $ 2.3 billion. 46% of Canada's iron ore comes from the Iron Ore Company of Canada mine, in Labrador City , Newfoundland , with secondary sources including the Mary River Mine in Nunavut . According to the U.S. Geological Survey's 2021 Report on iron ore, India is estimated to produce 59,000,000 t (58,000,000 long tons; 65,000,000 short tons) of iron ore in 2020, placing it as

962-564: Is a city in Lake County , Minnesota , United States. The population was 1,857 at the time of the 2020 census . It is the largest population center in a natural tourism area which includes Tettegouche State Park and the Split Rock Lighthouse . It is a port along Lake Superior for iron ore and has taconite mining facilities of its own. The North Shore National Scenic Drive runs through town. The city of Silver Bay

1036-511: Is a high-volume, low-margin business, as the value of iron is significantly lower than base metals. It is highly capital intensive, and requires significant investment in infrastructure such as rail in order to transport the ore from the mine to a freight ship. For these reasons, iron ore production is concentrated in the hands of a few major players. World production averages 2,000,000,000 t (2.0 × 10 long tons; 2.2 × 10 short tons) of raw ore annually. The world's largest producer of iron ore

1110-428: Is expected to rise by a CAGR of 2% between 2023 and 2027, and industry analyst Fitch Solutions forecasted in 2021 that Brazil's annual production will reach 592,000,000 t (583,000,000 long tons; 653,000,000 short tons) by 2030. In 2017, Canadian iron ore mines produced 49,000,000 t (48,000,000 long tons; 54,000,000 short tons) of iron ore in concentrate pellets and 13.6 million tons of crude steel. Of

1184-510: Is followed by Japan and Korea, which consume a significant amount of raw iron ore and metallurgical coal . In 2006, China produced 588,000,000 t (579,000,000 long tons; 648,000,000 short tons) of iron ore, with an annual growth of 38%. Over the last 40 years, iron ore prices have been decided in closed-door negotiations between the small handful of miners and steelmakers which dominate both spot and contract markets. Until 2006, prices were determined in annual benchmark negotiations between

1258-603: Is in the iron ranges around Lake Superior . These iron ranges occur in Minnesota and Michigan, which combined accounted for 93% of the usable iron ore produced in the United States in 2014. Seven of the nine operational open pit mines in the United States are located in Minnesota as well as two of the three tailings reclamation operations. The other two active open pit mines were located in Michigan . In 2016, one of

1332-709: Is mined extensively in Brazil as of 2019, which exports significant quantities to Asia , and there is a nascent and large magnetite iron ore industry in Australia . Direct-shipping iron ore (DSO) deposits (typically composed of hematite ) are currently exploited on all continents except Antarctica , with the largest intensity in South America , Australia, and Asia. Most large hematite iron ore deposits are sourced from altered banded iron formations and (rarely) igneous accumulations. DSO deposits are typically rarer than

1406-541: Is often discussed, this usage of the term is very common. The Mesabi Iron Range region of the American state of Minnesota is a major production area. The taconite iron ore pellets are hauled by railroad to the ports of Silver Bay , Two Harbors and the Twin Ports of Duluth, Minnesota , and Superior, Wisconsin , all on Lake Superior . The docks at Escanaba, Michigan , on Lake Michigan, also ship taconite from

1480-547: Is shipped to Mexico and China. The SS Edmund Fitzgerald , which sank in Lake Superior on November 10, 1975, was carrying about 26,116 long tons of taconite pellets. Beginning in 1955, Reserve Mining Company discharged crushed waste rock (tailings) from their Silver Bay, Minnesota processing plant into Lake Superior. The tailings contained 40% of the amphibole group mineral series cummingtonite - grunerite , which may form asbestiform particles. A small fraction of

1554-463: Is the raw material used to make pig iron , which is one of the main raw materials to make steel —98% of the mined iron ore is used to make steel. In 2011 the Financial Times quoted Christopher LaFemina, mining analyst at Barclays Capital, saying that iron ore is "more integral to the global economy than any other commodity, except perhaps oil ". Metallic iron is virtually unknown on

SECTION 20

#1732802466877

1628-481: Is the Brazilian mining corporation Vale , followed by Australian companies Rio Tinto Group and BHP . A further Australian supplier, Fortescue Metals Group Ltd, has helped bring Australia's production to first in the world. The seaborne trade in iron ore—that is, iron ore to be shipped to other countries—was 849,000,000 t (836,000,000 long tons; 936,000,000 short tons) in 2004. Australia and Brazil dominate

1702-425: Is used to produce sponge iron (Fe) to be used for steel-making. Direct reduction requires more energy, as the temperatures are higher and the time is longer and it requires more reducing agent than magnetizing roasting. Lower-grade sources of iron ore generally require beneficiation , using techniques like crushing, milling , gravity or heavy media separation , screening, and silica froth flotation to improve

1776-467: Is usually found in the form of magnetite ( Fe 3 O 4 , 72.4% Fe), hematite ( Fe 2 O 3 , 69.9% Fe), goethite ( FeO(OH) , 62.9% Fe), limonite ( FeO(OH)·n(H 2 O) , 55% Fe), or siderite ( FeCO 3 , 48.2% Fe). Ores containing very high quantities of hematite or magnetite, typically greater than about 60% iron, are known as natural ore or direct shipping ore , and can be fed directly into iron-making blast furnaces . Iron ore

1850-905: The Chichester Range , the Hamersley Range and Koolyanobbing , Western Australia . Other types of ore are coming to the fore recently, such as oxidised ferruginous hardcaps, for instance laterite iron ore deposits near Lake Argyle in Western Australia. The total recoverable reserves of iron ore in India are about 9,602,000,000 t (9.450 × 10 long tons; 1.0584 × 10 short tons) of hematite and 3,408,000,000 t (3.354 × 10 long tons; 3.757 × 10 short tons) of magnetite . Chhattisgarh , Madhya Pradesh , Karnataka , Jharkhand , Odisha , Goa , Maharashtra , Andhra Pradesh , Kerala , Rajasthan , and Tamil Nadu are

1924-602: The Earth 's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths . Although iron is the fourth-most abundant element in the Earth's crust , composing about 5%, the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive amount of energy. Therefore, all sources of iron used by human industry exploit comparatively rarer iron oxide minerals, primarily hematite . Prehistoric societies used laterite as

1998-564: The Pilbara region of Western Australia is approximately 844,000,000 t (831,000,000 long tons; 930,000,000 short tons) per year and rising. Gavin Mudd ( RMIT University ) and Jonathon Law ( CSIRO ) expect it to be gone within 30–50 years and 56 years, respectively. These 2010 estimates require ongoing review to take into account shifting demand for lower-grade iron ore and improving mining and recovery techniques (allowing deeper mining below

2072-458: The Rivers and Harbors Act of 1899 , which prohibited the dumping of harmful materials into interstate waters. In 1977, after a long trial, a new waste-storage facility was built 7 miles inland. Often referred to as “Mile Post 7” In 2015, the taconite tailing-rich Black Beach opened to the public, the negotiation with the mining company for public access to the beaches in the area being brokered by

2146-480: The census of 2010, there were 1,887 people, 836 households, and 542 families living in the city. The population density was 239.2 inhabitants per square mile (92.4/km ). There were 974 housing units at an average density of 123.4 per square mile (47.6/km ). The racial makeup of the city was 97.9% White , 0.2% African American , 0.3% Native American , 0.3% Asian , 0.3% from other races , and 1.0% from two or more races. Hispanic or Latino of any race were 0.9% of

2220-407: The silicate mineral fragments will float and can be removed. Iron is the world's most commonly used metal—steel, of which iron ore is the key ingredient, represents almost 95% of all metal used per year. It is used primarily in structures, ships, automobiles, and machinery. Iron-rich rocks are common worldwide, but ore-grade commercial mining operations are dominated by the countries listed in

2294-420: The 13,600,000 t (13,400,000 long tons; 15,000,000 short tons) of steel 7,000,000 t (6,900,000 long tons; 7,700,000 short tons) was exported, and 43,100,000 t (42,400,000 long tons; 47,500,000 short tons) of iron ore was exported at a value of $ 4.6 billion. Of the iron ore exported, 38.5% of the volume was iron ore pellets with a value of $ 2.3 billion, and 61.5% was iron ore concentrates with

Taconite - Misplaced Pages Continue

2368-691: The 62–64% Fe range. Granite and ultrapotassic igneous rocks were sometimes used to segregate magnetite crystals and form masses of magnetite suitable for economic concentration. A few iron ore deposits, notably in Chile , are formed from volcanic flows containing significant accumulations of magnetite phenocrysts . Chilean magnetite iron ore deposits within the Atacama Desert have also formed alluvial accumulations of magnetite in streams leading from these volcanic formations. Some magnetite skarn and hydrothermal deposits have been worked in

2442-705: The Canadian border. It is about halfway between Duluth and Grand Marais, along the North Shore of Lake Superior . Tettegouche State Park , the Baptism River , and the Palisade Head rock formation are all nearby. Summer hiking trails, winter cross country skiing, maintained snowmobile trails , multiple parks, a hockey arena, and 4 baseball/softball fields are located within Silver Bay. As of

2516-512: The Marquette iron range in Michigan, and occasionally ore from Minnesota is hauled by rail there. Marquette, Michigan , also has a taconite dock that loads bulk freighters with ore from the Marquette iron range. The ore is generally shipped by lake freighters to locations on the lower Great Lakes . Many steelmaking centers are near Lake Erie . Due to increased international demand, taconite

2590-429: The United States is estimated to have accounted for 2% of the world's iron ore output. In the United States there are twelve iron ore mines, with nine being open pit mines and three being reclamation operations. There were also ten pelletizing plants, nine concentration plants, two direct-reduced iron (DRI) plants, and one iron nugget plant that were operating in 2014. In the United States the majority of iron ore mining

2664-424: The United States was mining such an abundance of iron ore of high quality that taconite was considered an uneconomic waste product. By the end of World War II much of the high-grade iron ore in the United States had been exhausted, so taconite became valued as a new source of the metal. To process taconite, the ore is ground into a fine powder, the magnetite is separated from the gangue by strong magnets, and

2738-576: The city of Silver Bay and the state DNR . Black Beach Park contains three beaches and a municipally-owned campground. According to the United States Census Bureau , the city has a total area of 8.36 square miles (21.65 km ), of which 7.89 square miles (20.44 km ) is land and 0.47 square miles (1.22 km ) is water. Silver Bay is located 28 miles northeast of Two Harbors , 54 miles northeast of Duluth , 55 miles southwest of Grand Marais , and about 100 miles south of

2812-422: The city. The population density was 268.0 inhabitants per square mile (103.5/km ). There were 933 housing units at an average density of 120.9 per square mile (46.7/km ). The racial makeup of the city was 97.68% White , 0.05% African American , 1.11% Native American , 0.15% Asian , 0.05% Pacific Islander , 0.10% from other races , and 0.87% from two or more races. Hispanic or Latino of any race were 0.68% of

2886-411: The concentration of the ore and remove impurities. The results, high-quality fine ore powders, are known as fines. Magnetite is magnetic , and hence easily separated from the gangue minerals and capable of producing a high-grade concentrate with very low levels of impurities. The grain size of the magnetite and its degree of commingling with the silica groundmass determine the grind size to which

2960-533: The country's " economic demonstrated resources " of iron currently amount to 24 gigatonnes , or 24,000,000,000 t (2.4 × 10 long tons; 2.6 × 10 short tons). Another estimate places Australia's reserves of iron ore at 52,000,000,000 t (5.1 × 10 long tons; 5.7 × 10 short tons), or 30% of the world's estimated 170,000,000,000 t (1.7 × 10 long tons; 1.9 × 10 short tons), of which Western Australia accounts for 28,000,000,000 t (2.8 × 10 long tons; 3.1 × 10 short tons). The current production rate from

3034-584: The depletion of high-grade hematite ores in the United States, led after World War II to the development of lower-grade iron ore sources, principally the use of magnetite and taconite . Iron ore mining methods vary by the type of ore being mined. There are four main types of iron ore deposits worked currently, depending on the mineralogy and geology of the ore deposits. These are magnetite, titanomagnetite , massive hematite, and pisolitic ironstone deposits. The origin of iron can be ultimately traced to its formation through nuclear fusion in stars, and most of

Taconite - Misplaced Pages Continue

3108-410: The dominant mineral have been extensively mined since 1955 to produce iron ore pellets; the term 'taconite' has consequently been colloquially adapted to describe the magnetite iron-formation ores ( taconite iron ore ), the mining, milling, magnetic separation, and agglomerating process ( taconite process ), and the product iron ore pellets ( taconite pellets ). In the late 19th and early 20th centuries,

3182-497: The drinking water and Lake Superior must be protected from the asbestos-like particles. The Reserve Mine was forced to begin disposing of tailing wastes on the land, and to implement air pollution control equipment, instead of discharging them directly to Lake Superior. This became one of the costliest pollution prevention cases in U.S. history. Government-funded studies have found no adverse health effects from drinking Lake Superior water. A 2003 study of taconite miners concluded that

3256-411: The fine-grained tailings were shown to widely disperse along the western shore of Lake Superior, the source of drinking water for a number of cities; for example, tests of Duluth, Minnesota's water supply showed 100 billion fibers per liter of water. There was no epidemiological proof whether these particles caused cancer or were safe. On April 20, 1974, the U.S. District Court judge Miles Lord ruled that

3330-442: The gangue is separated during the beneficiation process and is removed as tailings . Taconite tailings are mostly the mineral quartz , which is chemically inert. This material is stored in large, regulated water settling ponds. The key parameters for magnetite ore being economic are the crystallinity of the magnetite, the grade of the iron within the banded iron formation host rock, and the contaminant elements which exist within

3404-800: The groundwater table). Brazil is the second-largest producer of iron ore after Australia, accounting for 16% of the world's iron ore production. After a somewhat sluggish production volume 2010-2020, partly due to the Mariana dam disaster in 2015 and the Brumadinho dam disaster in 2019, which halted the production at the two involved mines, production has increased steadily since 2021, when Brazil produced 431,000,000 t (424,000,000 long tons; 475,000,000 short tons). In 2022 it increased to 435,000,000 t (428,000,000 long tons; 480,000,000 short tons) and in 2023 to 440,000,000 t (430,000,000 long tons; 490,000,000 short tons). The Brazilian production

3478-450: The iron and carbon smelting must be kept in an oxygen-deficient (reducing) state to promote the burning of carbon to produce CO and not CO 2 . The inclusion of even small amounts of some elements can have profound effects on the behavioral characteristics of a batch of iron or the operation of a smelter. These effects can be both good and bad, some catastrophically bad. Some chemicals are deliberately added, such as flux, which makes

3552-413: The iron from the oxygen, a stronger elemental bond must be presented to attach to the oxygen. Carbon is used because the strength of a carbon-oxygen bond is greater than that of the iron-oxygen bond at high temperatures. Thus, the iron ore must be powdered and mixed with coke , to be burnt in the smelting process. Carbon monoxide is the primary ingredient of chemically stripping oxygen from iron. Thus,

3626-895: The iron is thought to have originated in dying stars that are large enough to explode as supernovae . The Earth's core is thought to consist mainly of iron, but this is inaccessible from the surface. Some iron meteorites are thought to have originated from asteroids 1,000 km (620 mi) in diameter or larger. Banded iron formations (BIFs) are sedimentary rocks containing more than 15% iron composed predominantly of thinly-bedded iron minerals and silica (as quartz ). Banded iron formations occur exclusively in Precambrian rocks, and are commonly weakly-to-intensely metamorphosed . Banded iron formations may contain iron in carbonates ( siderite or ankerite ) or silicates ( minnesotaite , greenalite , or grunerite ), but in those mined as iron ores, oxides ( magnetite or hematite ) are

3700-483: The iron mines and living to be 80 years old had a lifetime chance of having a mesothelioma of 3.33 cases per thousand such workers, more than double the background rate of 1.44 cases per thousand people living to 80 years old. Iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron

3774-423: The magnetite concentrate. The size and strip ratio of most magnetite resources is irrelevant, as a banded iron formation can be hundreds of meters thick, extend hundreds of kilometers along strike , and can easily come to more than three billion or more tonnes of contained ore. The typical grade of iron at which a magnetite-bearing banded iron formation becomes economic is roughly 25% iron, which can generally yield

SECTION 50

#1732802466877

3848-476: The magnetite-bearing BIF or other rocks which form its main source, or protolith rock, but are considerably cheaper to mine and process as they require less beneficiation due to the higher iron content. However, DSO ores can contain significantly higher concentrations of penalty elements, typically being higher in phosphorus, water content (especially pisolite sedimentary accumulations), and aluminium ( clays within pisolites). Export-grade DSO ores are generally in

3922-399: The main iron ore producers ( BHP Billiton , Rio Tinto , and Vale S.A. ) and Japanese importers. In 2006, Chinese company Baosteel began handling negotiations for the importer side. The Chinese government replaced Baosteel with China Iron and Steel Association as lead negotiator in 2009. Traditionally, the first deal reached between these the major producers and the major importers sets

3996-410: The mine tailings contain an average of approximately 11% iron, there would be approximately 1.41 million tons of iron wasted annually. These tailings are also high in other useful metals such as copper , nickel , and cobalt , and they can be used for road-building materials like pavement and filler and building materials such as cement, low-grade glass, and wall materials. While tailings are

4070-561: The most likely cause of 14 of the 17 cases of mesothelioma among miners on the iron range was contact with asbestos . Since that study was concluded, 35 more Iron Range miners have been diagnosed with the disease. Mesothelioma occurs at twice the expected rate among the population of the northeastern region of Minnesota, including the Iron Range . Spurred by the 2003 study, the Minnesota Department of Health (MDH) studied

4144-509: The past as high-grade iron ore deposits requiring little beneficiation . There are several granite-associated deposits of this nature in Malaysia and Indonesia . Other sources of magnetite iron ore include metamorphic accumulations of massive magnetite ore such as at Savage River , Tasmania , formed by shearing of ophiolite ultramafics . Another, minor, source of iron ores are magmatic accumulations in layered intrusions which contain

4218-464: The pelletized ore. Firing the pellet oxidizes the magnetite (Fe 3 O 4 ) to hematite (Fe 2 O 3 ), an exothermic reaction that reduces the cost of pelletizing the concentrate. E. W. Davis of the University of Minnesota Mines Experiment Station is credited with developing the pelletizing process. Since the commercial development of this process in the Lake Superior region in the 1950s,

4292-439: The population. There were 836 households, of which 22.8% had children under the age of 18 living with them, 53.3% were married couples living together, 6.7% had a female householder with no husband present, 4.8% had a male householder with no wife present, and 35.2% were non-families. 31.7% of all households were made up of individuals, and 15.9% had someone living alone who was 65 years of age or older. The average household size

4366-487: The population. Germans comprised 22.2% of the population, 18.1% Norwegian , 11.5% Swedish , 6.5% Finnish , 6.4% American , 6.1% Irish , and 5.2% English ancestry. There were 844 households, out of which 28.2% had children under the age of 18 living with them, 59.8% were married couples living together, 7.1% had a female householder with no husband present, and 30.1% were non-families. Individuals comprised 27.6% of all households, and 14.3% had someone living alone who

4440-421: The powdered iron concentrate is combined with a binder such as bentonite clay and limestone as a flux . As a last step, it is rolled into pellets about 10 millimeters in diameter that contain about 65% iron. The pellets are fired at a very high temperature to harden them and make them durable. This is to ensure that the blast furnace charge remains porous enough to allow heated gas to pass through and react with

4514-480: The principal Indian producers of iron ore. World consumption of iron ore grows 10% per year on average with the main consumers being China, Japan, Korea, the United States, and the European Union. China is currently the largest consumer of iron ore, which translates to be the world's largest steel producing country. It is also the largest importer, buying 52% of the seaborne trade in iron ore in 2004. China

SECTION 60

#1732802466877

4588-481: The principal iron mineral. Banded iron formations are known as taconite within North America. The mining involves moving tremendous amounts of ore and waste. The waste comes in two forms: non-ore bedrock in the mine ( overburden or interburden locally known as mullock), and unwanted minerals, which are an intrinsic part of the ore rock itself ( gangue ). The mullock is mined and piled in waste dumps , and

4662-429: The quartz is left behind when the resultant powder is passed under a magnetic separator. Generally, most magnetite banded iron formation deposits must be ground to between 32 and 45 μm (0.0013 and 0.0018 in) in order to produce a low-silica magnetite concentrate. Magnetite concentrate grades are generally in excess of 70% iron by weight and usually are low in phosphorus, aluminium, titanium, and silica and demand

4736-683: The relationship of fibrous minerals in taconite and taconite dust, and lung conditions similar to asbestosis , pleural mesothelioma and other pleural conditions which occur following asbestos exposure. Because these conditions can be triggered by industrial asbestos, which was used in taconite mining and processing, as well as other industrial facilities in northeastern Minnesota, the study attempted to determine what, if any, influence naturally occurring fibrous minerals in taconite may have played. The lengthy epidemiological study of Minnesota iron miners concluded in December 2014 that those working 30 years in

4810-407: The rock must be comminuted to enable efficient magnetic separation to provide a high-purity magnetite concentrate. This determines the energy inputs required to run a milling operation. Mining of banded iron formations involves coarse crushing and screening, followed by rough crushing and fine grinding to comminute the ore to the point where the crystallized magnetite and quartz are fine enough that

4884-446: The seaborne trade, with 72% of the market. BHP, Rio and Vale control 66% of this market between them. In Australia , iron ore is won from three main sources: pisolite " channel iron deposit " ore derived by mechanical erosion of primary banded-iron formations and accumulated in alluvial channels such as at Pannawonica, Western Australia ; and the dominant metasomatically altered banded iron formation -related ores such as at Newman ,

4958-464: The seventh largest global center of iron ore production, behind Australia, Brazil, China, India, Russia, and South Africa. Producers of iron ore in Ukraine include Ferrexpo , Metinvest , and ArcelorMittal Kryvyi Rih . In 2014, mines in the United States produced 57,500,000 t (56,600,000 long tons; 63,400,000 short tons) of iron ore with an estimated value of $ 5.1 billion. Iron mining in

5032-451: The seventh-largest global center of iron ore production, behind Australia, Brazil, China, Russia, South Africa, and Ukraine. India's iron ore production in 2023 was 285,000,000 metric tonnes and was the fourth largest producer in the world. According to the U.S. Geological Survey's 2021 Report on iron ore, Ukraine is estimated to have produced 62,000,000 t (61,000,000 long tons; 68,000,000 short tons) of iron ore in 2020, placing it as

5106-401: The table aside. The major constraint to economics for iron ore deposits is not necessarily the grade or size of the deposits, because it is not particularly hard to geologically prove enough tonnage of the rocks exist. The main constraint is the position of the iron ore relative to market, the cost of rail infrastructure to get it to market, and the energy cost required to do so. Mining iron ore

5180-451: The term "taconite" has been used globally to refer to iron ores amenable to upgrading by similar processes. Major producers of iron ore pellets from taconite in North America include Iron Ore Company of Canada , Cliffs Natural Resources, Inc. , U.S. Steel , and ArcelorMittal . These processed taconite-ore pellets are also referred to as "taconite". Because this is the form that is typically transported by rail and ship, and cargo of these

5254-602: The two mines shut down. There have also been iron ore mines in Utah and Alabama ; however, the last iron ore mine in Utah shut down in 2014 and the last iron ore mine in Alabama shut down in 1975. Iron ores consist of oxygen and iron atoms bonded together into molecules. To convert it to metallic iron, it must be smelted or sent through a direct reduction process to remove the oxygen. Oxygen-iron bonds are strong, and to remove

5328-431: Was 2.17 and the average family size was 2.69. The median age in the city was 50.1 years. 18.4% of residents were under the age of 18; 6.9% were between the ages of 18 and 24; 17.4% were from 25 to 44; 28.6% were from 45 to 64; and 28.8% were 65 years of age or older. The gender makeup of the city was 51.8% male and 48.2% female. As of the census of 2000, there were 2,068 people, 844 households, and 589 families living in

5402-451: Was 65 years of age or older. The average household size was 2.35 and the average family size was 2.85. In the city, the population was spread out, with 24.4% under the age of 18, 4.3% from 18 to 24, 23.4% from 25 to 44, 20.8% from 45 to 64, and 27.2% who were 65 years of age or older. The median age was 44 years. For every 100 females, there were 104.8 males. For every 100 females age 18 and over, there were 105.8 males. The median income for

5476-576: Was founded on May 1, 1954, after previously being known as the Beaver Bay housing project. The company town was built to process taconite mined and shipped by train from Babbitt, Minnesota , sixty miles to the northwest. Silver Bay attained widespread publicity in the 1960s when it was discovered that the Reserve Corporation was dumping taconite tailings into Lake Superior. In 1972 they were forced to stop and charged with violating

#876123