I Can’t Sleep - Iron | Calm Bedtime Reading for Sleep

Episode Date: May 15, 2023

Drift off with this calm bedtime reading as Benjamin explores the story of iron, helping you relax and ease insomnia. You’ll learn how this vital element shaped human history, from ancient tools and... weapons to its role in industry, construction, and daily life. Benjamin’s soothing cadence turns metallurgy and history into peaceful storytelling that reduces stress and quiets the mind. This isn’t whispering or hypnosis—just gentle, fact-filled narration designed to guide you into rest. Press play, settle in, and let this exploration of iron carry you into a deep and refreshing sleep. Want More? Request a Topic: https://www.icantsleeppodcast.com/request-a-topic Ad-Free Episodes: https://icantsleep.supportingcast.fm/ Shop Sleep-Friendly Products: https://www.icantsleeppodcast.com/sponsors Join the Discussion on Discord: https://discord.gg/myhGhVUhn7 This content is derived from the Wikipedia article on Iron, available under the Creative Commons Attribution-ShareAlike (CC BY-SA) license. Read the full article: Wikipedia – Iron. Happy sleeping! Learn more about your ad choices. Visit megaphone.fm/adchoices

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Starting point is 00:00:03 You're listening to a Glassbox media podcast. What if I told you that most of the modern day self-help advice you've been hearing could actually make you worse? The key to a better life isn't about feel-good gimmicks that sound catchy. The Mentally Stronger Podcast gives you access to a licensed therapist who shares science-backed tools that will actually change your life. Hi, I'm Amy Morin, psychotherapist, mental strength trainer, and international best-selling author. In each episode, we cover research-back strategies, like how to stop relying on willpower and start creating habits for lasting change. And the five mental strength-building exercises you can do from your couch. I also speak to world-class experts like Dr. Nicole Kane, who shares how to permanently heal anxiety by addressing the root cause.
Starting point is 00:00:57 With over 200 episodes in our catalog, this podcast is for you if you're ready to crush self-doubt, conquer challenges, become stronger than ever with therapist-approved strategies that can change your life. Listen to Mentally Stronger with Therapist Amy Morin, wherever you get your podcasts. Welcome to the I Can't Sleep Podcast, a glass box media podcast, where I read random articles from across the web to bore you to sleep with my soothing voice. I'm your host, Benjamin Boster. Today's episode is from a Wikipedia article titled Iron. Iron is a chemical. element with the symbol F.E. from Latin Ph.m. Iron. And atomic number 26. It is a metal that belongs to the first transition series and group eight of the periodic table. It is, by mass, the most common
Starting point is 00:02:12 element on Earth, just ahead of oxygen, 32.1 percent and 30.1 percent, respectively, forming much of Earth's outer and inner core. It is the fourth most most, common element in the earth's crust being mainly deposited by meteorites in its metallic state, with its ore also being found there. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching 1,500 degrees Celsius or higher, about 500 degrees Celsius higher than that required to smelt copper. Humans started to master that process in Eurasia during the second millennium BCE, and the use of iron tools and weapons began to displace copper alloys, in some regions only around 1,200 BCE.
Starting point is 00:03:05 That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys such as steel, stainless steel, cast iron, and special steels are by far the most common industrial metals, due to their mechanical properties and low cost. The iron and steel industry is thus very important economically, and iron is the cheapest metal, with a price of a few dollars per kilogram or pound. Pristine and smooth pure iron surfaces are a mirror-like silvery gray. Iron reacts readily with oxygen and water to produce brown-to-black hydrated iron oxides, commonly known as rust. Unlike the oxides of some other metals that form passive aiding layers,
Starting point is 00:03:59 rust occupies more volume than the metal and thus flakes off, exposing more fresh surfaces for corrosion. High purity irons, i.e. electrolytic iron, are more resistant to corrosion. The body of an adult human contains about 4 grams.005% body weight of iron, mostly in hemoglobin and myoglobin. These two proteins play essential roles in vertebrate metabolism, respectively oxygen transport by blood and oxygen storage in muscles. To maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet.
Starting point is 00:04:45 Iron is also the metal at the active site of many important redox enzymes, dealing with cellular respiration and oxidation and reduction in plants and animals. Chemically, the most common oxidation states of iron are iron 2 and iron 3. Iron shares many properties of other transition metals, including the other group 8 elements, rousenium and osmium. Iron forms compounds in a wide range of oxidation states. negative 2 to plus 7. Iron also forms many coordination compounds.
Starting point is 00:05:27 Some of them such as ferocene, ferroxylate, and Prussian blue, have substantial industrial medical or research applications. Characteristics Allotropes At least four allotropes of iron differing atom arrangements in the solid are known, conventionally denoted alpha, gamma, delta, epsilon. The first three forms are observed at ordinary pressures. As molten iron cools past its freezing point of 1,538 degrees Celsius, it crystallizes into its delta alatrope, which has a body
Starting point is 00:06:09 centered cubic BCC crystal structure, as it cools further to 1,394 degrees Celsius. It changes to its gamma-iron allotrope, a face-centered cubic FCC crystal structure, or austinite. At 912 degrees Celsius and below, the crystal structure again becomes the BCC alpha iron allotrope. The physical properties of iron at very high pressures and temperatures have also been studied extensively because of the relevance to theories about the cores of the Earth and other planets. Above approximately 10 gigapascals and temperatures of a few hundred Kelvin or less, alpha iron changes into another hexagonal close-packed HCP structure, which is also known as Epsilon Iron.
Starting point is 00:07:05 The higher temperature gamma phase also changes into Epsilon Iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable beta phase at pressures above 50 gigapascals and temperatures of at least 1,500 Kelvin. It is supposed to have an orthorhombic or a double HCP structure. Confusingly, the term beta iron is sometimes also used to refer to alpha iron above its curie point when it changes from being ferromagnetic to paramagnetic, even though its crystal structure has not changed.
Starting point is 00:07:42 The inner core of the Earth is generally presumed to consist of an iron-nickel alloy with epsilon or beta structure. The melting and boiling points. The melting and boiling points of iron along with its enthalpy of atomization are lower than those of the earlier third elements from scandium to chromium, showing the lessened contribution of the third electrons to metallic bonding, as they are attracted more and more into the inert core by the nucleus. However, they are higher than the values for the previous element manganese because that element
Starting point is 00:08:22 has a half-filled third sub-shell, and consequently its de-electrons are not easily delocalized. This same trend appears for ruthenium, but not osmium. The melting point of iron is experimentally well-defined for pressures less than 50 gigapascals. For greater pressures, published data still varies, by tens of gigapascals and over a thousand Kelvin. Magnetic properties. Below its curie point of 770 degrees Celsius, alpha iron changes from paramagnetic to ferromagnetic.
Starting point is 00:09:03 The pins of the two unpaired electrons in each atom generally align with the pins of its neighbors, creating an overall magnetic field. This happens because the orbits of those two electrons do not point toward neighboring atoms in the lattice. and therefore are not involved in metallic bonding. In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains,
Starting point is 00:09:29 about 10 micrometers across, such that the atoms in each domain have parallel spins, but some domains have other orientations. Thus, a macroscopic piece of iron will have a nearly zero overall magnetic field. application of an external magnetic field causes the domains that are magnetized in the same general direction to grow at the expense of adjacent ones that point in other directions reinforcing the external field. This effect is exploited in devices that need to channel magnetic fields to fulfill design function, such as electrical transformers, magnetic recording heads, and electric motors.
Starting point is 00:10:11 impurities, lattice defects, or grain and particle boundaries can pin the domains in the new positions so that the effect persists even after the external field is removed, thus turning the iron object into a permanent magnet. Similar behavior is exhibited by some iron compounds, such as the ferrites including the mineral magnetite, a crystalline form of the mixed iron 2 and 3 oxide FE3.0.5.5.5.0. although the atomic scale mechanism paramagnetism is somewhat different. Pieces of magnetite with natural permanent magnetization iodostones provided the earliest compasses for navigation. Particles of magnetite were extensively used in magnetic recording media,
Starting point is 00:11:03 such as core memories, magnetic tapes, floppies, and disks, until they were replaced by cobalt-based materials. Isotopes. Iron has four stable isotopes. FE, 5.845% of natural iron. 54 FE, 5.845% of natural iron. 56 FE, 91.754%. 57FE, 2.119%, and 58 FE. 0282%.
Starting point is 00:11:41 24 artificial isotopes have also also been created. Of these stable isotopes, only 57-FE has a nuclear spin minus one-half. The nucleide 54-FE theoretically can undergo double electron capture to 54-CR. But the process has never been observed, and only a lower limit on the half-life of 3.1 times 10 to the 22nd years has been established. 60FE is an extinct radio nucleide of long half-life, 2.6 million years. It is not found on Earth, but its ultimate decay product is its granddaughter, the stable nucleide, 60NI. Much of the past work on isotopic composition of iron has focused on the nucleosynthesis
Starting point is 00:12:31 of 60FE through studies of meteorites and ore formation. In the last decade, advances in massachusetts in mass. mass spectrometry have allowed the detection and quantification of minute naturally occurring variations in the ratios of the stable isotopes of iron. Much of this work is driven by the Earth and planetary science communities, although applications to biological and industrial systems are emerging. In phases of the meteorites, Semarcona and Chervone Kood, a correlation between the concentration of 60NI, the granddaughter of 60 FE, and the abundance of the stable iron isotopes provided evidence for the existence of 60 FE at the time of formation of the solar system.
Starting point is 00:13:21 Possibly the energy released by the decay of 60FE, along with that released by 26AL, contributed to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. The abundance of 60 N.I. Present in extraterrestrial material may bring further insight into the origin and early history of the solar system. The most abundant iron isotope 56FE is of particular interest to nuclear scientists because it represents the most common endpoint of nucleosynthesis. Since 56NI, 14 alpha particles, is easily produced from lighter nuclei in the alpha process, nuclear reactions in supernovae. It is the end point of fusion chains inside extremely massive stars,
Starting point is 00:14:14 since addition of another alpha particle resulting in 60 ZN requires a great deal more energy. This 56NI, which has a half-life of about six days, is created in quantity in these stars, but soon decays by two successive positron emissions within supernova decay products in the supernova remnant gas cloud, first to radioactive 56-CO, and then to stable 56-FE. As such, iron is the most abundant element in the core of red giants, and is the most abundant material in iron meteorites, and in the dense metal cores of planets, such as Earth. It is also very common in the universe, relative to other stable metals of approximately the same atomic weight. Iron is the sixth most abundant element in the universe and the most common refractory element.
Starting point is 00:15:10 Although a further tiny energy gain could be extracted by synthesizing 62 NI, which has a marginally higher binding energy than 56FE, conditions and stars are unsuitable for this process. Element production in supernovas greatly favor iron over nickel, and in any case, 56FE still has a lower mass per nucleon than 62 NI due to its higher fraction of lighter protons. Hence, elements heavier than iron require a supernova for their formation, involving rapid neutron capture by starting 56FE nuclei. In the far future of the universe, assuming that proton decay does not occur, cold fusion occurring via quantum tunneling would cause the light nuclei in ordinary matter to fuse into F56 F-E nuclei.
Starting point is 00:16:04 Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting all stellar mass objects to cold spheres of pure iron. Origin and occurrence in nature Cosmogenesis Iron's abundance and rocky planets like Earth is due to its abundant production during the runaway fusion and explosion of type 1A supernovae, which scatters the iron.
Starting point is 00:16:34 into space. Metallic iron. Metallic or native iron is rarely found on the surface of the earth because it tends to oxidize. However, both the Earth's inner and outer core, which together account for 35% of the mass of the whole Earths, are believed to consist largely of an iron alloy, possibly with nickel. Electric currents in the liquid outer core are believed to be the origin of the Earth's magnetic field. The other terrestrial planets, Mercury, Venus, and Mars, as well as the Moon, are believed to have a metallic core consisting mostly of iron. The M-type asteroids are also believed to be partly or mostly made of a metallic iron alloy.
Starting point is 00:17:21 The rare iron meteorites are the main form of natural metallic iron on the Earth's surface. Items made of cold work meteoritic iron have been found in various archaeological sites. dating from a time when iron smelting had not yet been developed, and the Inuit in Greenland have been reported to use iron from the Cape York meteorite for tools and hunting weapons. About 1 and 20 meteorites consist of the unique iron nickel minerals, tainide, 35 to 80% iron, and Camasite 90 to 95% iron. Native iron is also rarely found in basalts that have formed from magma, that have come into contact with carbon-rich sedimentary rocks,
Starting point is 00:18:08 which have reduced the oxygen fugacity sufficiently for iron to crystallize. This is known as Tellerick iron and is described from a few localities, such as Disco Island in West Greenland, Yakusha in Russia, and Bull in Germany. Mantle minerals Faro Paraclase M-G-F-E-O, a solid solution of pericles M-G-O and Vustite F-E-O makes up about 20% of the volume of the lower mantle of the earth, which makes it the second most abundant mineral phase in that region after silicate, M-G-F-E-S-I-O-3.
Starting point is 00:18:52 It also is the major host for iron in the lower mantle. Silicate paraviskyte may form up to 93% of the lower mantle, and the magnesium iron form M-G-F-E-I-O-3 is considered to be the most abundant mineral in the earth, making up 38% of its volume. Earth's crust While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. The fraction of iron that is Earth's crust only amounts to about 5% of the overall mass of the crust,
Starting point is 00:19:30 and is thus only the fourth most abundant element. in that layer after oxygen, silicon, and aluminum. Most of the iron in the crust is combined with various other elements to form many iron minerals. An important class is the iron oxide minerals such as hematite F.E.2.3. Magnetite F.E.304 and ciderite Fec Ores of iron. Many igneous rocks also contain the sulfide minerals pyrotite, and pendentide. During weathering, iron tends to leach from sulfide deposits as the sulfate and from silicate deposits as the bicarbonate. Both of these are oxidized in aquaous solution
Starting point is 00:20:17 and precipitate an even mildly elevated pH as iron-3 oxide. Large deposits of iron are banded iron formations, a type of rock consisting of repeated thin layers of iron oxides alternating with bands of iron poor shale and chert. The banded iron formations were laid down in the time between 3,700 million years ago and 1,800 million years ago. Materials containing finely ground iron three oxides of oxide hydroxides, such as ochre, have been used as yellow, red, and brown pigments since pre-historical times. They contribute as well to the color of various rocks and clays, including entire geological formations like the painted hills in Oregon and Bunstenstein-colored sandstone, British Bunter. Through Eisenzgenstein, a Jurassic Iron Sandstone,
Starting point is 00:21:15 e.g. from Donsdorf in Germany, and Bathstone in the UK, iron compounds are responsible for the yellowish color of many historical buildings and sculptures. The proverbial red color of the surface of Mars is derived from an iron oxide-rich regolith. Significant amounts of iron occur in the iron sulfide mineral pyride, FES2, but it is difficult to extract iron from it and is therefore not exploited. In fact, iron is so common that production generally focuses only on ores with very high quantities of it. According to the International Resource Panel's metal stocks in society report, the global stock of iron in use in society is 2,200 kilograms per capita. More developed countries differ in this respect from less developed countries.
Starting point is 00:22:09 7,000 to 14,000 versus 2,000 kilograms per capita. Oceans Ocean science demonstrated the role of the iron in the ancient seas in both the marine biota and climate. Chemistry and compounds. Iron shows the characteristic chemical properties of the transition metals, namely the ability to form variable oxidation states differing by steps of one, and a very large coordination in organa-metallic chemistry. Indeed, it was the discovery of an iron compound forestine that revolutionized the latter field in the 1950s. Iron is sometimes considered as a prototype for the entire block of transition metals
Starting point is 00:22:59 due to its abundance and the immense role it has played in the technological progress of humanity. Its 26 electrons are arranged in the configuration AR 3D6 4S2, of which the 3D and 4S electrons are relatively close in energy, and thus a number of electrons can be ionized. Iron forms compounds mainly in the oxidation states plus 2, Iron 2 Ferris, and plus 3, Iron 3 ferric. Iron also occurs in higher oxidation states, i.e. the purple potassium ferrate K2-FE.O-4, which contains iron in its plus 6 oxidation state. The anion F.E.04 minus with iron in its plus seven oxidation state, along with an iron 5 paroxo isomer, has been detected by infrared spectroscopy at 4K after co-condensation of laser-ablated F.E. atoms with a mixture of O2A.R. Iron 4 is a common intermediate in many biochemical oxidation reactions.
Starting point is 00:24:13 Numerous organo-iron compounds contain formal oxidation states of plus 1, 0, negative 1, or even negative 2. The oxidation states and other bonding properties are often assessed using the technique of Musbauer spectroscopy. Many mixed valence compounds contain both iron 2 and iron 3 centers, such as magnetite and Prussian blue, FE4-FECN-6-3. The latter is used as the traditional blue in blueprints. Iron is the first of the transition metals that cannot reach its group oxidation state of plus 8, although its heavier congeners ruthinium and osmium can, with ruthenium having more difficulty than osmium.
Starting point is 00:25:06 Ruthenium exhibits an aqueous cadionic chemistry in its low oxidation state similar to that iron, but osmium does not favoring high oxidation states in which it forms anionic complexes. In the second half of the 3D transition series, vertical similarities down the groups compete with the horizontal similarities of iron with its neighbors cobalt and nickel in the periodic, which are also ferromagnetic at room temperature and share similar chemistry. as such iron, cobalt, and nickel are sometimes grouped together as the iron triad. Unlike many other metals, iron does not form amalgams with mercury. As a result, mercury is traded in standardized 76-pound flasks made of iron.
Starting point is 00:26:00 Iron is by far the most reactive element in its group. It is pyrophoric when finely divided and dissolves easily in dilute acids. giving FE2 plus. However, it does not react with concentrated nitric acid and other oxidizing acids due to the formation of an impervious oxide layer, which can nevertheless react with hydrochloric acid. High purity iron, called electrolytic iron, is considered to be resistant to rust due to its oxide layer.
Starting point is 00:26:36 Binary compounds Oxides and sulfides Iron forms various oxide and hydroxide compounds. The most common are iron 2-3 oxide F.E.304 and iron-3 oxide F-E-203. Iron-2 oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds, whose compositions may vary. These oxides are the principal ores for the production of iron. They are also used in the production of ferrites,
Starting point is 00:27:15 useful magnetic storage media and computers, and pigments. The best-known sulfide is iron pyrite, FES2, also known as Fools cold owing to its golden luster. Hallides. The binary ferrous and ferric halides are well known. The ferrous halides typically arise from treating iron metal with the corresponding hydrochallic acid to give the corresponding hydrated salts. Iron reacts with fluorine, chlorine, and bromine to give the corresponding ferric halides,
Starting point is 00:27:53 ferric chloride being the most common. Ferric iodide is an exception being thermodynamically unstable due to the oxidizing power of FE3 plus and the high reducing power of i minus. Ferric iodide is not stable in ordinary conditions, but can be prepared through the reaction of iron pentacarbonell with iodine and carbon monoxide in the presence of hexane and light at the temperature of minus 20 degrees Celsius, with oxygen and water excluded. Complexes of ferric iodide with some soft bases are known to be stable compounds. Organomotelic compounds
Starting point is 00:28:34 Organo-iron chemistry is the study of organometallic compounds of iron, where carbon atoms are covalently bound to the metal atom. They are many and varied, including cyanide complexes, carbonyl complexes, sandwich, and half-samwich compounds. Prussian blue or ferric ferocyanide, FE4, FECN6, 3, is an old and well-known iron cyanide complex. extensively used as pigment and in several other applications. Its formation can be used as a simple wet chemistry test to distinguish between aqueous solutions of FE2 plus and FE3 plus as they react, respectively with potassium ferocyanide and potassium ferocyanide to form Prussian blue. Another old example of an organo-iron compound is iron pentacarboneil.
Starting point is 00:29:34 FECO5, in which a neutral iron atom is bound to the carbon atoms of five carbon monoxide molecules. The compound can be used to make carbonyl iron powder, a highly reactive form of metallic iron. Thermalysis of iron pentacarbonil gives tri-iron dodeca carbonyl FE3CO12, a complex with a cluster of three iron atoms at its core. Coleman's reagent disodium tetracarbonil ferrate is a useful reagent for organic chemistry. It contains iron in the minus two oxidation state. History. Development of iron metallurgy. Iron is one of the elements undoubtedly known to the ancient world. It has been worked or wrought for millennia. However, iron artifacts of great age are much rarer than a very rare. objects made of gold or silver, due to the ease with which iron corrods.
Starting point is 00:30:38 The technology developed slowly, and even after the discovery of smelting, it took many centuries for iron to replace bronze as the metal of choice for tools and weapons. Meteoric iron Beads made from meteoric iron in 3,500 BC or earlier were found in GERSA, Egypt, by G.A. Wainwright. The beads contain 7.5% nickel, which is a signature of meteoric origin, since iron found in the earth's crust generally has only minuscule nickel impurities. Meteoric iron was highly regarded due to its origin in the heavens and was often used to forge weapons and tools. For example, a dagger made of meteoric iron was found in the tomb of two-ton-common, containing similar properties of iron,
Starting point is 00:31:30 cobald and nickel to a meteorite discovered in the area deposited by an ancient meteor shower. Items that were likely made of iron by Egyptians date from 3,000 to 2000 BC. Meteoric iron is comparably soft and ductile and easily cold-forged, but may get brittle when heated because of the nickel content. Rot iron. The first iron production started in the middle Bronze Age, but it took several centuries before iron displaced bronze. Samples of smelted iron from Osmar, Mesopotamia, and Tal-Chagar Bazaar in northern Syria, were made sometime between 3,000 and 2,700 BC.
Starting point is 00:32:17 The Hittites established an empire in north-central Anatolia around 1600 BC. They appear to be the first to understand the production of iron from its ores and regard it highly in their society. The Hittites began to smelt iron between 1,500 and 1,200 BC, and the practice spread to the rest of the Near East after their empire fell in 1180 BC. The subsequent period is called the Iron Age. Artifacts of smelted iron are found in India, dating from 1800 to 1200 BC, and in the Levant from about 1,500 BC, suggesting smelting in Antolia or the Caucasus. Alleged references to iron in the Indian Vedas has been used for claims of a very early usage of iron in India, respectively to date the texts as such. The Rigveda terms ayas metal refers to copper, while iron which is called Sayymas ayos, literally
Starting point is 00:33:19 black copper, first is mentioned in the post-rig Vedic Atharveveda. Some archaeological evidence suggests iron was smelted in Zimbabwe. and Southeast Africa as early as the 8th century BC. Iron working was introduced to Greece in the late 11th century BC, from which it spread quickly throughout Europe. The spread of iron working in Central and Western Europe is associated with Celtic expansion. According to Pliny the Elder, iron use was common in the Roman era. In the lands of what is now considered China, iron appears approximately 700 to 500 to 5. 500 BC. Iron smelting may have been introduced in China through Central Asia. The earliest evidence of the use of a blast furnace in China dates the first century AD and cupola furnaces were used as early as the
Starting point is 00:34:16 warring states period, 403 to 221 BC. Usage of the blast and cupola furnace remained widespread during the Tang and Song dynasties. During the Industrial Revolution, In the revolution in Britain, Henry Court began refining iron from pig iron to rot iron or bar iron using innovative production systems. In 1783, he patented the puddling process for refining iron ore. It was later improved by others, including Joseph Hall. Cast iron. Cast iron was first produced in China during 5th century BC, but was hardly in Europe until the medieval period. The earliest cast iron artifacts were discovered by archaeologists in what is now modern Luhay County, Jiangshu, and China.
Starting point is 00:35:11 Cast iron was used in ancient China for warfare, agriculture, and architecture. During the medieval period, means were found in Europe of producing wrought iron from cast iron, in this context known as pig iron, using finery forges. For all these processes, charcoal was required as fast iron. fuel. Medieval blast furnaces were about 10 feet tall and made of fireproof brick. Forced air was usually provided by hand-operated bellows. Modern blast furnaces have grown much bigger, with Har's 14 meters in diameter, that allow them to produce thousands of tons of iron each day, but essentially operate in much the same way as they did during medieval times. In 1709, Abraham Darby
Starting point is 00:36:01 the first established a coke-fired blast furnace to produce cast iron, replacing charcoal, although continuing to use blast furnaces. The ensuing availability of inexpensive iron was one of the factors leading to the industrial revolution. Toward the end of the 18th century, cast iron began to replace wrought iron for certain purposes. because it was cheaper. Carbon content in iron was not implicated as a reason for the differences in properties of wrought iron, cast iron, and steel until the 18th century. Since iron was becoming cheaper and more plentiful, it also became a major structural material
Starting point is 00:36:44 following the building of the innovative first iron bridge in 1778. This bridge still stands today as a monument to the role iron played in the industrial revolution. Following this, iron was used in rails, boats, ships, aqueducts, and buildings, as well as in iron cylinders in steam engines. Railways have been central to the formation of modernity and ideas of progress, and various languages refer to railways as iron road. Steel. Steel was smaller carbon content that pig iron, but more than wrought iron, was first produced in antiquity by using a bloomery. Blacksmiths in Luriston in western Persia were making good steel by 1,000 BC. Then improved versions, wood steel by India and Damascus steel, were developed
Starting point is 00:37:43 around 300 BC and AD 500 respectively. These methods were specialized and so steel did not become a major commodity until the 1850s. New methods of producing it by carburizing bars of iron in the cementation process were devised in the 17th century. In the Industrial Revolution, new methods of producing bar iron without charcoal were devised, and these were later applied to produce steel. In the late 1850s, Henry Bessemer invented a new steel-making process, involving blowing air through molten pig iron to produce mild steel.
Starting point is 00:38:26 This made steel much more economical, thereby leading to wrought iron no longer being produced in large quantities. Foundations of Modern Chemistry In 1774, Antoine Lavoisier used the reaction of water steam with metallic iron inside an incandescent iron tube to produce hydrogen, in his experiments leading to the demonstration of the conservation of mass, which was instrumental in changing chemistry from a qualitative science to a quantitative one. Symbolic role.
Starting point is 00:39:05 Iron plays a certain role in mythology and has found various usage as a metaphor and in folklore. The Greek poet Hesiod's works and days lists different ages of man named after metals like gold, silver, bronze, and iron, to account for successive ages of humanity. The Iron Age was closely related with Rome and in Ovid's metamorphosis. The virtues in despair quit the earth, and the depravity of man becomes universal and complete. Hard steel succeeded then. Ovid, Metamorphosis, Book 1, Iron Age, Line 160. An example of the importance of iron's symbolic role may be found in the German campaign of 1813.
Starting point is 00:39:53 Frederick William III commissioned then the first Iron Cross as military decoration. Berlin Iron Jewelry reached its peak production between 1813 and 1815, when the Prussian royal family urged citizens to donate gold and silver jewelry for military funding. The inscription Gold Gopich for Eisen I have gold for iron, was used as well in later war efforts. Production of metallic iron. Laboratory routes. For a few limited purposes when it's needed,
Starting point is 00:40:29 pure iron is produced in the laboratory in small quantities by reducing the pure oxide of hydroxide with hydrogen, or forming iron pentacarbonell and heating it to 250 degrees Celsius so that it decomposes to form pure iron powder. Another method is electrolysis of ferrous chloride into an iron cathode. Main industrial route. Nowadays, the industrial production of iron or steel consists of two main stages. In the first stage, iron ore is reduced with coke in a blast furnace,
Starting point is 00:41:06 and the molten metal is separated from gross impurities such as silicate minerals. This stage yields an alloy, pig iron, that contains relatively large amounts of carbon. In the second stage, the amount of carbon in the pig iron is lowered by oxidation to yield wrought iron, steel, or cast iron. Other metals can be added at this stage to form alloy steels. Blast furnace processing The blast furnace is loaded with iron ores, usually hematite FE203 or magnetite FE304, along with coke, coal that has been separately baked to remove volatile. components and flux, limestone or dolomite. Blasts of air preheated to 900 degrees Celsius, sometimes with oxygen enrichment, is blown through the mixture in sufficient amount to turn
Starting point is 00:42:03 the carbon into carbon monoxide. This reaction raises the temperature to about 2,000 degrees Celsius. The carbon monoxide reduces the iron or to metallic iron. Some iron in the high temperature, lower region of the furnace reacts directly with the coke. The flux removes silicatious minerals in the ore, which would otherwise clog the furnace. The heat of the furnace decomposes the carbonates to calcium oxide, which reacts with any excess silica to form a slag composed of calcium silicate, C-A-S-I-O-3, or other products.
Starting point is 00:42:43 At the furnace's temperature, the metal and the slag are both molten, They collect at the bottom as two emissible liquid layers with the slag on top that are then easily separated. The slag can be used as a material in road construction or to improve mineral-poor soils for agriculture. Steelmaking thus remains one of the largest industrial contributors of CO2 emissions in the world. Steelmaking The pig iron produced by the blast furnace process contains up to 4 to 5% carbon by, mass, with small amounts of other impurities like sulfur, magnesium, phosphorus, and manganese. This high level of carbon makes it relatively weak and brittle.
Starting point is 00:43:31 Reducing the amount of carbon to 0.002 to 2.1% produces steel, which may be up to 1,000 times harder than pure iron. A great variety of steel articles can then be made by cold working, hot rolling, forging, and machining, etc. Removing the impurities from pig iron, but leaving 2 to 4% carbon results in cast iron, which is cast by foundries into articles such as stoves, pipes, radiators, lamp posts, and rails.
Starting point is 00:44:06 Steel products often undergo various heat treatments after they are forged to shape. A kneeling consists of heating them to 700 to 800 to 800 degrees Celsius for several hours, and then gradual cooling. It makes this deal softer and more workable.

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