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84-458: The standard was originally developed to carry very large loads of iron ore to China from Brazilian port facilities operated by mineral firm Vale . Correspondingly, harbours and other infrastructure that are "Chinamax-compatible" are those at which such ships can readily dock. Unlike Suezmax and Panamax , Chinamax is not determined by locks or channels , or bridges—the Chinamax standard

168-612: A face-centered cubic lattice and iron cations occupying interstitial sites . Half of the Fe cations occupy tetrahedral sites while the other half, along with Fe cations, occupy octahedral sites. The unit cell consists of thirty-two   O ions and unit cell length is a = 0.839 nm. As a member of the inverse spinel group, magnetite can form solid solutions with similarly structured minerals, including ulvospinel ( Fe 2 TiO 4 ) and magnesioferrite ( MgFe 2 O 4 ). Titanomagnetite, also known as titaniferous magnetite,

252-528: 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

336-696: 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

420-468: 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. Magnetite Magnetite

504-571: A compass in Tasmania to keep navigation problems to the minimum. Magnetite crystals with a cubic habit are rare but have been found at Balmat, St. Lawrence County, New York , and at Långban, Sweden . This habit may be a result of crystallization in the presence of cations such as zinc. Magnetite can also be found in fossils due to biomineralization and are referred to as magnetofossils . There are also instances of magnetite with origins in space coming from meteorites . Biomagnetism

588-463: A component of protein plaques in the brain. Such plaques have been linked to Alzheimer's disease . Increased iron levels, specifically magnetic iron, have been found in portions of the brain in Alzheimer's patients. Monitoring changes in iron concentrations may make it possible to detect the loss of neurons and the development of neurodegenerative diseases prior to the onset of symptoms due to

672-536: A crystal structure phase transition from a monoclinic structure to a cubic structure known as the Verwey transition . Optical studies show that this metal to insulator transition is sharp and occurs around 120   K. The Verwey transition is dependent on grain size, domain state, pressure, and the iron-oxygen stoichiometry . An isotropic point also occurs near the Verwey transition around 130   K, at which point

756-430: A highly porous high-surface-area material, which enhances its effectiveness as a catalyst. Magnetite micro- and nanoparticles are used in a variety of applications, from biomedical to environmental. One use is in water purification: in high gradient magnetic separation, magnetite nanoparticles introduced into contaminated water will bind to the suspended particles (solids, bacteria, or plankton, for example) and settle to

840-431: A human health hazard, airborne magnetite is a result of pollution (specifically combustion). These nanoparticles can travel to the brain via the olfactory nerve, increasing the concentration of magnetite in the brain. In some brain samples, the nanoparticle pollution outnumbers the natural particles by as much as 100:1, and such pollution-borne magnetite particles may be linked to abnormal neural deterioration. In one study,

924-424: 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

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1008-453: 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

1092-503: A science important in understanding plate tectonics and as historic data for magnetohydrodynamics and other scientific fields . The relationships between magnetite and other iron oxide minerals such as ilmenite , hematite, and ulvospinel have been much studied; the reactions between these minerals and oxygen influence how and when magnetite preserves a record of the Earth's magnetic field . At low temperatures, magnetite undergoes

1176-616: 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

1260-606: 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

1344-418: 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

1428-800: A type of ship or boat is a stub . You can help Misplaced Pages by expanding it . 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 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

1512-655: 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,

1596-659: 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

1680-529: A vast deposit of magnetite-bearing sand dunes in Peru . The dune field covers 250 square kilometers (100 sq mi), with the highest dune at over 2,000 meters (6,560 ft) above the desert floor. The sand contains 10% magnetite. In large enough quantities magnetite can affect compass navigation . In Tasmania there are many areas with highly magnetized rocks that can greatly influence compasses. Extra steps and repeated observations are required when using

1764-416: Is Fe (Fe ) 2 (O ) 4 . This indicates that magnetite contains both ferrous ( divalent ) and ferric ( trivalent ) iron, suggesting crystallization in an environment containing intermediate levels of oxygen. The main details of its structure were established in 1915. It was one of the first crystal structures to be obtained using X-ray diffraction . The structure is inverse spinel , with O ions forming

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1848-496: Is a mineral and one of the main iron ores , with the chemical formula Fe Fe 3+ 2 O 4 . It is one of the oxides of iron , and is ferrimagnetic ; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone , will attract small pieces of iron, which

1932-511: 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

2016-517: Is a solid solution between magnetite and ulvospinel that crystallizes in many mafic igneous rocks. Titanomagnetite may undergo oxy-exsolution during cooling, resulting in ingrowths of magnetite and ilmenite. Natural and synthetic magnetite occurs most commonly as octahedral crystals bounded by {111} planes and as rhombic-dodecahedra . Twinning occurs on the {111} plane. Hydrothermal synthesis usually produces single octahedral crystals which can be as large as 10 mm (0.39 in) across. In

2100-418: Is aimed at port provisions and the name is derived from the massive dry-bulk (ore) shipments that China receives from around the globe. In container shipping, recent classes intended for trade with China have all focused on a ~400 meter length , which deep water container terminals can cater for. This China -related article is a stub . You can help Misplaced Pages by expanding it . This article about

2184-703: Is also a chemical basis for cellular sensitivity to electric and magnetic fields ( galvanotaxis ). Pure magnetite particles are biomineralized in magnetosomes , which are produced by several species of magnetotactic bacteria . Magnetosomes consist of long chains of oriented magnetite particle that are used by bacteria for navigation. After the death of these bacteria, the magnetite particles in magnetosomes may be preserved in sediments as magnetofossils. Some types of anaerobic bacteria that are not magnetotactic can also create magnetite in oxygen free sediments by reducing amorphic ferric oxide to magnetite. Several species of birds are known to incorporate magnetite crystals in

2268-426: Is burnt (oxidized) to give magnetite or wüstite of a defined particle size. The magnetite (or wüstite) particles are then partially reduced, removing some of the oxygen in the process. The resulting catalyst particles consist of a core of magnetite, encased in a shell of wüstite, which in turn is surrounded by an outer shell of iron metal. The catalyst maintains most of its bulk volume during the reduction, resulting in

2352-428: 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

2436-510: 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

2520-726: Is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak . Small grains of magnetite are very common in igneous and metamorphic rocks . The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ferrous-ferric oxide . In addition to igneous rocks, magnetite also occurs in sedimentary rocks , including banded iron formations and in lake and marine sediments as both detrital grains and as magnetofossils . Magnetite nanoparticles are also thought to form in soils, where they probably oxidize rapidly to maghemite . The chemical composition of magnetite

2604-603: 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

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2688-709: 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

2772-606: Is sometimes found in large quantities in beach sand. Such black sands (mineral sands or iron sands ) are found in various places, such as Lung Kwu Tan in Hong Kong; California , United States; and the west coast of the North Island of New Zealand. The magnetite, eroded from rocks, is carried to the beach by rivers and concentrated by wave action and currents. Huge deposits have been found in banded iron formations. These sedimentary rocks have been used to infer changes in

2856-453: Is still not well understood, and there has been a general lag in applying more modern, interdisciplinary techniques to the study of biomagnetism. Electron microscope scans of human brain-tissue samples are able to differentiate between magnetite produced by the body's own cells and magnetite absorbed from airborne pollution, the natural forms being jagged and crystalline, while magnetite pollution occurs as rounded nanoparticles . Potentially

2940-463: 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

3024-481: 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

3108-425: 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

3192-452: Is usually related to the presence of biogenic crystals of magnetite, which occur widely in organisms. These organisms range from magnetotactic bacteria (e.g., Magnetospirillum magnetotacticum ) to animals, including humans, where magnetite crystals (and other magnetically sensitive compounds) are found in different organs, depending on the species. Biomagnetites account for the effects of weak magnetic fields on biological systems. There

3276-905: 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

3360-551: 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

3444-564: 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

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3528-407: 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

3612-420: 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

3696-691: 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

3780-527: The QFM buffer. At still lower oxygen levels, magnetite forms a buffer with wüstite known as the MW buffer. The QFM and MW buffers have been used extensively in laboratory experiments on rock chemistry. The QFM buffer, in particular, produces an oxygen fugacity close to that of most igneous rocks. Commonly, igneous rocks contain solid solutions of both titanomagnetite and hemoilmenite or titanohematite. Compositions of

3864-429: 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

3948-460: The bottom of the fluid, allowing the contaminants to be removed and the magnetite particles to be recycled and reused. This method works with radioactive and carcinogenic particles as well, making it an important cleanup tool in the case of heavy metals introduced into water systems. Another application of magnetic nanoparticles is in the creation of ferrofluids . These are used in several ways. Ferrofluids can be used for targeted drug delivery in

4032-410: The brain – magnetite, hemoglobin (blood) and ferritin (protein), and areas of the brain related to motor function generally contain more iron. Magnetite can be found in the hippocampus . The hippocampus is associated with information processing, specifically learning and memory. However, magnetite can have toxic effects due to its charge or magnetic nature and its involvement in oxidative stress or

4116-565: The characteristic nanoparticles were found in the brains of 37 people: 29 of these, aged 3 to 85, had lived and died in Mexico City, a significant air pollution hotspot. Some of the further eight, aged 62 to 92, from Manchester, England, had died with varying severities of neurodegenerative diseases. Such particles could conceivably contribute to diseases like Alzheimer's disease . Though a causal link has not yet been established, laboratory studies suggest that iron oxides such as magnetite are

4200-411: 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

4284-533: 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

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4368-584: 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

4452-442: 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

4536-800: 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

4620-402: The human body. The magnetization of the particles bound with drug molecules allows "magnetic dragging" of the solution to the desired area of the body. This would allow the treatment of only a small area of the body, rather than the body as a whole, and could be highly useful in cancer treatment, among other things. Ferrofluids are also used in magnetic resonance imaging (MRI) technology. For

4704-450: 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

4788-413: 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,

4872-895: 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

4956-500: The magnetic fields the organism was exposed to, potentially allowing scientists to learn about the migration of the organism or about changes in the Earth's magnetic field over time. Living organisms can produce magnetite. In humans, magnetite can be found in various parts of the brain including the frontal , parietal , occipital , and temporal lobes , brainstem , cerebellum and basal ganglia . Iron can be found in three forms in

5040-423: 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

5124-461: The magnetite with needle-shaped particles of gamma ferric oxide (γ-Fe 2 O 3 ). Approximately 2–3% of the world's energy budget is allocated to the Haber Process for nitrogen fixation, which relies on magnetite-derived catalysts. The industrial catalyst is obtained from finely ground iron powder, which is usually obtained by reduction of high-purity magnetite. The pulverized iron metal

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5208-476: 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

5292-399: 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

5376-410: 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

5460-418: The mineral pairs are used to calculate oxygen fugacity: a range of oxidizing conditions are found in magmas and the oxidation state helps to determine how the magmas might evolve by fractional crystallization . Magnetite also is produced from peridotites and dunites by serpentinization . Lodestones were used as an early form of magnetic compass . Magnetite has been a critical tool in paleomagnetism ,

5544-596: The mineral. In the municipalities of Molinaseca, Albares, and Rabanal del Camino, in the province of León (Spain), there is a magnetite deposit in Ordovician terrain, considered one of the largest in Europe. It was exploited between 1955 and 1982. Deposits are also found in Norway , Romania , and Ukraine . Magnetite-rich sand dunes are found in southern Peru. In 2005, an exploration company, Cardero Resources, discovered

5628-639: The oxygen content of the atmosphere of the Earth. Large deposits of magnetite are also found in the Atacama region of Chile ( Chilean Iron Belt ); the Valentines region of Uruguay; Kiruna , Sweden; the Tallawang region of New South Wales; and in the Adirondack Mountains of New York in the United States. Kediet ej Jill , the highest mountain of Mauritania , is made entirely of

5712-509: 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

5796-403: The presence of mineralizers such as 0.1   M HI or 2   M NH 4 Cl and at 0.207   MPa at 416–800 °C, magnetite grew as crystals whose shapes were a combination of rhombic-dodechahedra forms. The crystals were more rounded than usual. The appearance of higher forms was considered as a result from a decrease in the surface energies caused by the lower surface to volume ratio in

5880-480: 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

5964-481: 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

6048-405: The production of free radicals . Research suggests that beta-amyloid plaques and tau proteins associated with neurodegenerative disease frequently occur after oxidative stress and the build-up of iron. Some researchers also suggest that humans possess a magnetic sense, proposing that this could allow certain people to use magnetoreception for navigation. The role of magnetite in the brain

6132-429: 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

6216-534: The relationship between magnetite and ferritin . In tissue, magnetite and ferritin can produce small magnetic fields which will interact with magnetic resonance imaging (MRI) creating contrast. Huntington patients have not shown increased magnetite levels; however, high levels have been found in study mice. Due to its high iron content, magnetite has long been a major iron ore . It is reduced in blast furnaces to pig iron or sponge iron for conversion to steel . Audio recording using magnetic acetate tape

6300-407: 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

6384-427: The rounded crystals. Magnetite has been important in understanding the conditions under which rocks form. Magnetite reacts with oxygen to produce hematite , and the mineral pair forms a buffer that can control how oxidizing its environment is (the oxygen fugacity ). This buffer is known as the hematite-magnetite or HM buffer. At lower oxygen levels, magnetite can form a buffer with quartz and fayalite known as

6468-446: 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 ,

6552-464: 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

6636-451: 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

6720-420: The sign of the magnetocrystalline anisotropy constant changes from positive to negative. The Curie temperature of magnetite is 580 °C (853 K; 1,076 °F). If magnetite is in a large enough quantity it can be found in aeromagnetic surveys using a magnetometer which measures magnetic intensities. Solid magnetite particles melt at about 1,583–1,597 °C (2,881–2,907 °F). Magnetite

6804-401: 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

6888-602: 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

6972-453: The upper beak for magnetoreception , which (in conjunction with cryptochromes in the retina ) gives them the ability to sense the direction, polarity , and magnitude of the ambient magnetic field . Chitons , a type of mollusk, have a tongue-like structure known as a radula , covered with magnetite-coated teeth, or denticles . The hardness of the magnetite helps in breaking down food. Biological magnetite may store information about

7056-480: Was developed in the 1930s. The German magnetophon first utilized magnetite powder that BASF coated onto cellulose acetate before soon switching to gamma ferric oxide for its superior morphology. Following World War II , 3M Company continued work on the German design. In 1946, the 3M researchers found they could also improve their own magnetite-based paper tape, which utilized powders of cubic crystals, by replacing

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