Listing description:
Iron (US pronunciation: /ˈaɪ.ərn/, with two syllables, and UK pronunciation: /aɪən/, with one) is a chemical element with the symbol Fe (Latin: ferrum) and atomic number 26. It is a metal in the first transition series. Like other group 8 elements, it exists in a wide range of oxidation states. Iron and iron alloys (steels) are by far the most common metals and the most common ferromagnetic materials in everyday use. Fresh iron surfaces appear lustrous silvery-gray, but oxidize in air.
Detailed
description
Iron
is the most common element in the earth as a whole, and the fourth most common
in the Earth's crust. It is produced as a result of stellar fusion in high-mass
stars, and it is the heaviest stable element produced by stellar fusion because
the fusion of iron is the last nuclear fusion reaction that is exothermic.
Iron is the most widely used metal, and iron compounds, which include ferrous
and ferric compounds, have several uses as well.
Iron
has been used since ancient times, though not as early as bronze or the other
copper related alloys. Iron is ubiquitous in modern life; it is used primarily
for its structural strength. Pure iron is soft (softer than aluminium),
but the material is significantly strengthened by addition of minute amounts of
impurities, such as carbon. Alloying iron with appropriate small amounts (up to
a few per cent) of other metals and carbon produces steel, which can be
1,000 times harder than pure iron. Iron is smelted in a blast furnace,
where ore is reduced by coke to metallic iron..
Elemental
iron is reactive; it oxidizes in air to give iron oxides,
also known as rust. The rusting of iron and iron alloys is undesirable, and has
a major economic impact. Unlike many other metals which form passivating oxide
layers, iron oxides occupy more volume than iron itself. Thus, iron oxides
flake off and expose fresh surfaces for corrosion. Iron oxide mixed with aluminium
powder can be ignited to create a thermite
reaction, used in welding and purifying ores.
Iron
exists from oxidation state −2 to + 6, although +2 and +3 are the most common.
It forms binary compounds with the halogens and the chalcogens. Among its
organometallic compounds, ferrocene was the first sandwich
compound discovered. Iron plays an important role in biology,
forming complexes with dioxygen as hemoglobin
and myoglobin;
these two compounds are common oxygen
transport proteins in vertebrates.
Iron
is of greatest importance when mixed with certain other metals and with carbon
to form steels. There are many types of steels, all with different properties,
and an understanding of the properties of the allotropes of iron is key to the manufacture of
good quality steels.
Alpha
iron, also known as ferrite, is the most stable form of iron at normal
temperatures. It is a fairly soft metal that can dissolve only a small
concentration of carbon (no more than 0.021% by mass at 910 °C).
Above
912 °C and up to 1400 °C α-iron undergoes a phase
transition from bcc to the fcc configuration of γ-iron, also called austenite.
This is similarly soft and metallic but can dissolve considerably more carbon
(as much as 2.04% by mass at 1146 °C). This form of iron is used in the
type of stainless steel used for making cutlery, and
hospital and food-service equipment.
Isotopes
Main
Isotopes of
iron
Naturally
occurring iron consists of four stable isotopes:
5.845% of 54Fe, 91.754% of 56Fe, 2.119% of 57Fe and 0.282% of 58Fe. The nuclide
54Fe is predicted to undergo double beta
decay, but this process had never been observed experimentally for
these nuclei, and only the lower limit on the half-life was established:
T1/2>3.1×1022 years. 60Fe is an extinct radionuclide of long half-life
(2.6 million years).
Much
of the past work on measuring the isotopic composition of Fe has focused on determining
Fe variations due to processes accompanying nucleosynthesis
(i.e., meteorite
studies) and ore formation. In the last decade however, advances in mass
spectrometry technology have allowed the detection and
quantification of minute, naturally occurring variations in the ratios of the stable
isotopes of iron. Much of this work has been driven by the Earth
and planetary science communities, although
applications to biological and industrial systems are beginning to emerge.
[edit] Blast furnace
Main
article: Blast furnace
Ninety
percent of all mining
of metallic ores
is for the extraction of iron[citation needed]. Industrially, iron
production involves iron ores, principally hematite
(nominally Fe2O3) and magnetite (Fe3O4) in a carbothermic
reaction (reduction with carbon) in a blast furnace at temperatures of about
2000 °C. In a blast furnace, iron ore, carbon in the form of coke,
and a flux such as limestone (which is used to remove silicon dioxide impurities
in the ore which would otherwise clog the furnace with solid material) are fed
into the top of the furnace, while a massive blast of heated air, about 4 tons, per ton of iron,[38]
is forced into the furnace at the bottom.
The
flux is present to melt impurities in the ore, principally silicon
dioxide sand
and other silicates.
Common fluxes include limestone (principally calcium
carbonate) and dolomite (calcium-magnesium carbonate). Other fluxes
may be used depending on the impurities that need to be removed from the ore.
In the heat of the furnace the limestone flux decomposes to calcium oxide
(also known as quicklime):
CaCO3
→ CaO + CO2
Then
calcium oxide combines with silicon dioxide to form a liquid slag.
CaO
+ SiO2 → CaSiO3
The
slag melts in the heat of the furnace. In the bottom of the furnace, the molten
slag floats on top of the denser molten iron, and apertures in the side of the
furnace are opened to run off the iron and the slag separately. The iron, once
cooled, is called pig iron, while the slag can be used as a material in road construction or to
improve mineral-poor soils for agriculture.
Creation
Iron
is created in extremely large, extremely hot (over 2.5 billion kelvin) stars,
in a process called the silicon burning process. It is the last
element to be produced in this manner. The process starts with the second
largest stable nucleus created by silicon burning: calcium. One stable nucleus
of calcium fuses with one helium nucleus, creating unstable titanium. Before
the titanium decays, it can fuse with another helium nucleus, creating unstable
chromium. Before the chromium decays, it can fuse with another helium nucleus,
creating unstable iron. Before the iron decays, it can fuse with another helium
nucleus, creating unstable nickel. The nickel then decays to unstable cobalt,
which finally decays to stable iron-56. The iron can no longer be fused with other elements.
As the star's core fills with iron, it begins to cool until there is no longer
enough energy to maintain its size. It then collapses and the result is a
supernova. Supernovas
also create additional forms of stable iron via the r-process.
The
first iron production started in the Middle Bronze
Age but it took several centuries before iron displaced bronze.
Samples of smelted
iron from Asmar,
Mesopotamia and Tall Chagar Bazaar in
northern Syria were made sometime between 2700 and 3000 BC.[30]
The Hittites
appear to be the first to understand the production of iron from its ores and
regard it highly in their society.They began to smelt iron between 1500 and
1200 BC and the practice spread to the rest of the Near East after their
empire fell in 1180 BC.[30]
The subsequent period is called the Iron Age.
Iron smelting, and thus the Iron Age, reached Europe two hundred years later
and arrived in Zimbabwe,
Africa by the 8th century.
The
Book of
Genesis, fourth chapter, verse 22 contains the first mention of iron
in the Old Testament of the Bible; "Tubal-cain,
an instructor of every artificer in brass and iron. Other verses allude to iron
mining (Job 28:2), iron used as a stylus (Job 19:24), furnace (Deuteronomy
4:20), chariots (Joshua 17:16), nails (I Chron. 22:3), saws and axes (II Sam.
12:31), and cooking utensils (Ezekiel 4:3). The metal is also mentioned in the New Testament,
for example in Acts chapter 12 verse 10, "[Peter passed through] the iron
gate that leadeth unto the city" of Antioch.
Mechanical
properties
Mechanical
properties of iron and its alloys are evaluated using a variety of tests, such
as the Brinell test, Rockwell test,
or tensile strength tests, among others; the
results on iron are so consistent that iron is often used to calibrate
measurements or to relate the results of one test to another.Those measurements
reveal that mechanical properties of iron crucially depend on purity: Purest
research-purpose single crystals of iron are softer than aluminium. Addition of
only 10 parts per million of carbon doubles their
strength. The hardness increases rapidly with carbon content up to 0.2% and
saturates at ~0.6%. The purest industrially produced iron (about 99.99% purity)
has a hardness of 20–30 Brinell.
Blast
furnace
Main
article: Blast furnace
Ninety
percent of all mining
of metallic ores
is for the extraction of iron.. Industrially, iron production involves iron
ores, principally hematite (nominally Fe2O3) and magnetite
(Fe3O4) in a carbothermic reaction (reduction with carbon)
in a blast furnace at temperatures of about 2000 °C. In a blast furnace,
iron ore, carbon in the form of coke,
and a flux such as limestone (which is used to remove silicon dioxide impurities
in the ore which would otherwise clog the furnace with solid material) are fed
into the top of the furnace, while a massive blast of heated air, about 4 tons, per ton of iron, is forced
into the furnace at the bottom.
Ore
The main ores of Iron we have in this part of the world includes:magnetites pyrites asenopyrites marcasites, laterites,hematites,banded iron formation,limonites and indeed numerous iron tailings. In this parts we can claim that we have the largest concentration of iron ore in Africa and we in franchise enterprises are happy to supply leading industries world wild the much needed raw materials it needs to function at full capacity.
PRICE
$96/MT
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
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