Iron is an element of the side subgroup of the eighth group of the fourth period of the periodic system of chemical elements of D.I. Mendeleev with atomic number 26. It is designated by the symbol Fe (lat. Ferrum). One of the most common metals in the earth's crust (second place after aluminum). Medium activity metal, reducing agent.
Main oxidation states - +2, +3
The simple substance iron is a malleable silver-white metal with high chemical reactivity: iron quickly corrodes at high temperatures or high humidity in the air. Iron burns in pure oxygen, and in a finely dispersed state it spontaneously ignites in air.
Chemical properties of a simple substance - iron:
Rusting and burning in oxygen
1) In air, iron easily oxidizes in the presence of moisture (rusting):
4Fe + 3O 2 + 6H 2 O → 4Fe(OH) 3
Hot iron wire burns in oxygen, forming scale - iron oxide (II, III):
3Fe + 2O 2 → Fe 3 O 4
3Fe+2O 2 →(Fe II Fe 2 III)O 4 (160 °C)
2) At high temperatures (700–900°C), iron reacts with water vapor:
3Fe + 4H 2 O – t° → Fe 3 O 4 + 4H 2
3) Iron reacts with non-metals when heated:
2Fe+3Cl 2 →2FeCl 3 (200 °C)
Fe + S – t° → FeS (600 °C)
Fe+2S → Fe +2 (S 2 -1) (700°C)
4) In the voltage series, it is to the left of hydrogen, reacts with dilute acids HCl and H 2 SO 4, and iron(II) salts are formed and hydrogen is released:
Fe + 2HCl → FeCl 2 + H 2 (reactions are carried out without air access, otherwise Fe +2 is gradually converted by oxygen to Fe +3)
Fe + H 2 SO 4 (diluted) → FeSO 4 + H 2
In concentrated oxidizing acids, iron dissolves only when heated; it immediately transforms into the Fe 3+ cation:
2Fe + 6H 2 SO 4 (conc.) – t° → Fe 2 (SO 4) 3 + 3SO 2 + 6H 2 O
Fe + 6HNO 3 (conc.) – t° → Fe(NO 3) 3 + 3NO 2 + 3H 2 O
(in the cold, concentrated nitric and sulfuric acids passivate
An iron nail immersed in a bluish solution of copper sulfate gradually becomes coated with a coating of red metallic copper.
5) Iron displaces metals located to the right of it from solutions of their salts.
Fe + CuSO 4 → FeSO 4 + Cu
The amphoteric properties of iron appear only in concentrated alkalis during boiling:
Fe + 2NaOH (50%) + 2H 2 O= Na 2 ↓+ H 2
and a precipitate of sodium tetrahydroxoferrate(II) is formed.
Technical hardware- alloys of iron and carbon: cast iron contains 2.06-6.67% C, steel 0.02-2.06% C, other natural impurities (S, P, Si) and artificially introduced special additives (Mn, Ni, Cr) are often present, which gives iron alloys technically useful properties - hardness, thermal and corrosion resistance, malleability, etc. .
Blast furnace iron production process
The blast furnace process for producing cast iron consists of the following stages:
a) preparation (roasting) of sulfide and carbonate ores - conversion to oxide ore:
FeS 2 →Fe 2 O 3 (O 2,800°C, -SO 2) FeCO 3 →Fe 2 O 3 (O 2,500-600°C, -CO 2)
b) combustion of coke with hot blast:
C (coke) + O 2 (air) → CO 2 (600-700 ° C) CO 2 + C (coke) ⇌ 2 CO (700-1000 ° C)
c) reduction of oxide ore with carbon monoxide CO sequentially:
Fe2O3 →(CO)(Fe II Fe 2 III) O 4 →(CO) FeO →(CO) Fe
d) carburization of iron (up to 6.67% C) and melting of cast iron:
Fe (t ) →(C(coke)900-1200°С) Fe (liquid) (cast iron, melting point 1145°C)
Cast iron always contains cementite Fe 2 C and graphite in the form of grains.
Steel production
The conversion of cast iron into steel is carried out in special furnaces (converter, open-hearth, electric), which differ in the heating method; process temperature 1700-2000 °C. Blowing air enriched with oxygen leads to the burning out of excess carbon, as well as sulfur, phosphorus and silicon in the form of oxides from the cast iron. In this case, the oxides are either captured in the form of exhaust gases (CO 2, SO 2), or are bound into an easily separated slag - a mixture of Ca 3 (PO 4) 2 and CaSiO 3. To produce special steels, alloying additives of other metals are introduced into the furnace.
Receipt pure iron in industry - electrolysis of a solution of iron salts, for example:
FeСl 2 → Fe↓ + Сl 2 (90°С) (electrolysis)
(there are other special methods, including the reduction of iron oxides with hydrogen).
Pure iron is used in the production of special alloys, in the manufacture of cores of electromagnets and transformers, cast iron - in the production of castings and steel, steel - as structural and tool materials, including wear-, heat- and corrosion-resistant ones.
Iron(II) oxide F EO . An amphoteric oxide with a high predominance of basic properties. Black, has an ionic structure Fe 2+ O 2- . When heated, it first decomposes and then forms again. It is not formed when iron burns in air. Does not react with water. Decomposes with acids, fuses with alkalis. Slowly oxidizes in humid air. Reduced by hydrogen and coke. Participates in the blast furnace process of iron smelting. It is used as a component of ceramics and mineral paints. Equations of the most important reactions:
4FeO ⇌(Fe II Fe 2 III) + Fe (560-700 °C, 900-1000 °C)
FeO + 2HC1 (diluted) = FeC1 2 + H 2 O
FeO + 4HNO 3 (conc.) = Fe(NO 3) 3 +NO 2 + 2H 2 O
FeO + 4NaOH = 2H 2 O + Na 4FeO3(red.) trioxoferrate(II)(400-500 °C)
FeO + H 2 =H 2 O + Fe (extra pure) (350°C)
FeO + C (coke) = Fe + CO (above 1000 °C)
FeO + CO = Fe + CO 2 (900°C)
4FeO + 2H 2 O (moisture) + O 2 (air) →4FeO(OH) (t)
6FeO + O 2 = 2(Fe II Fe 2 III) O 4 (300-500°C)
Receipt V laboratories: thermal decomposition of iron (II) compounds without air access:
Fe(OH) 2 = FeO + H 2 O (150-200 °C)
FeCO3 = FeO + CO 2 (490-550 °C)
Diiron(III) oxide - iron( II ) ( Fe II Fe 2 III)O 4 . Double oxide. Black, has the ionic structure Fe 2+ (Fe 3+) 2 (O 2-) 4. Thermally stable up to high temperatures. Does not react with water. Decomposes with acids. Reduced by hydrogen, hot iron. Participates in the blast furnace process of cast iron production. Used as a component of mineral paints ( red lead), ceramics, colored cement. Product of special oxidation of the surface of steel products ( blackening, bluing). The composition corresponds to brown rust and dark scale on iron. The use of the gross formula Fe 3 O 4 is not recommended. Equations of the most important reactions:
2(Fe II Fe 2 III)O 4 = 6FeO + O 2 (above 1538 °C)
(Fe II Fe 2 III) O 4 + 8НС1 (dil.) = FeС1 2 + 2FeС1 3 + 4Н 2 O
(Fe II Fe 2 III) O 4 +10HNO 3 (conc.) = 3Fe(NO 3) 3 + NO 2 + 5H 2 O
(Fe II Fe 2 III) O 4 + O 2 (air) = 6 Fe 2 O 3 (450-600 ° C)
(Fe II Fe 2 III)O 4 + 4H 2 = 4H 2 O + 3Fe (extra pure, 1000 °C)
(Fe II Fe 2 III) O 4 + CO = 3 FeO + CO 2 (500-800°C)
(Fe II Fe 2 III)O4 + Fe ⇌4FeO (900-1000 °C, 560-700 °C)
Receipt: combustion of iron (see) in air.
magnetite.
Iron(III) oxide F e 2 O 3 . Amphoteric oxide with a predominance of basic properties. Red-brown, has an ionic structure (Fe 3+) 2 (O 2-) 3. Thermally stable up to high temperatures. It is not formed when iron burns in air. Does not react with water, brown amorphous hydrate Fe 2 O 3 nH 2 O precipitates from the solution. Reacts slowly with acids and alkalis. Reduced by carbon monoxide, molten iron. Fuses with oxides of other metals and forms double oxides - spinels(technical products are called ferrites). It is used as a raw material in the smelting of cast iron in the blast furnace process, a catalyst in the production of ammonia, a component of ceramics, colored cements and mineral paints, in thermite welding of steel structures, as a carrier of sound and image on magnetic tapes, as a polishing agent for steel and glass.
Equations of the most important reactions:
6Fe 2 O 3 = 4(Fe II Fe 2 III)O 4 +O 2 (1200-1300 °C)
Fe 2 O 3 + 6НС1 (dil.) →2FeС1 3 + ЗН 2 O (t) (600°С, р)
Fe 2 O 3 + 2NaOH (conc.) →H 2 O+ 2 NAFeO 2 (red)dioxoferrate(III)
Fe 2 O 3 + MO = (M II Fe 2 II I) O 4 (M = Cu, Mn, Fe, Ni, Zn)
Fe 2 O 3 + ZN 2 = ZN 2 O+ 2Fe (extra pure, 1050-1100 °C)
Fe 2 O 3 + Fe = 3FeO (900 °C)
3Fe 2 O 3 + CO = 2(Fe II Fe 2 III)O 4 + CO 2 (400-600 °C)
Receipt in the laboratory - thermal decomposition of iron (III) salts in air:
Fe 2 (SO 4) 3 = Fe 2 O 3 + 3SO 3 (500-700 °C)
4(Fe(NO 3) 3 9 H 2 O) = 2Fe a O 3 + 12NO 2 + 3O 2 + 36H 2 O (600-700 °C)
In nature - iron oxide ores hematite Fe 2 O 3 and limonite Fe 2 O 3 nH 2 O
Iron(II) hydroxide F e(OH) 2 . Amphoteric hydroxide with a predominance of basic properties. White (sometimes with a greenish tint), Fe-OH bonds are predominantly covalent. Thermally unstable. Easily oxidizes in air, especially when wet (it darkens). Insoluble in water. Reacts with dilute acids and concentrated alkalis. Typical reducer. An intermediate product in the rusting of iron. It is used in the manufacture of the active mass of iron-nickel batteries.
Equations of the most important reactions:
Fe(OH) 2 = FeO + H 2 O (150-200 °C, atm.N 2)
Fe(OH) 2 + 2HC1 (dil.) = FeC1 2 + 2H 2 O
Fe(OH) 2 + 2NaOH (> 50%) = Na 2 ↓ (blue-green) (boiling)
4Fe(OH) 2 (suspension) + O 2 (air) →4FeO(OH)↓ + 2H 2 O (t)
2Fe(OH) 2 (suspension) +H 2 O 2 (diluted) = 2FeO(OH)↓ + 2H 2 O
Fe(OH) 2 + KNO 3 (conc.) = FeO(OH)↓ + NO+ KOH (60 °C)
Receipt: precipitation from solution with alkalis or ammonia hydrate in an inert atmosphere:
Fe 2+ + 2OH (dil.) = Fe(OH) 2 ↓
Fe 2+ + 2(NH 3 H 2 O) = Fe(OH) 2 ↓+ 2NH 4
Iron metahydroxide F eO(OH). Amphoteric hydroxide with a predominance of basic properties. Light brown, Fe - O and Fe - OH bonds are predominantly covalent. When heated, it decomposes without melting. Insoluble in water. Precipitates from solution in the form of a brown amorphous polyhydrate Fe 2 O 3 nH 2 O, which, when kept under a dilute alkaline solution or upon drying, turns into FeO(OH). Reacts with acids and solid alkalis. Weak oxidizing and reducing agent. Sintered with Fe(OH) 2. An intermediate product in the rusting of iron. It is used as a base for yellow mineral paints and enamels, an absorber for waste gases, and a catalyst in organic synthesis.
The compound of composition Fe(OH) 3 is unknown (not obtained).
Equations of the most important reactions:
Fe 2 O 3 . nH 2 O→( 200-250 °C, —H 2 O) FeO(OH)→( 560-700° C in air, -H2O)→Fe 2 O 3
FeO(OH) + ZNS1 (dil.) = FeC1 3 + 2H 2 O
FeO(OH)→ Fe 2 O 3 . nH 2 O-colloid(NaOH (conc.))
FeO(OH)→ Na 3 [Fe(OH) 6 ]white, Na 5 and K 4 respectively; in both cases, a blue product of the same composition and structure, KFe III, precipitates. In the laboratory this precipitate is called Prussian blue, or turnbull blue:
Fe 2+ + K + + 3- = KFe III ↓
Fe 3+ + K + + 4- = KFe III ↓
Chemical names of the starting reagents and reaction products:
K 3 Fe III - potassium hexacyanoferrate (III)
K 4 Fe III - potassium hexacyanoferrate (II)
КFe III - iron (III) potassium hexacyanoferrate (II)
In addition, a good reagent for Fe 3+ ions is the thiocyanate ion NСS -, iron (III) combines with it, and a bright red (“bloody”) color appears:
Fe 3+ + 6NCS - = 3-
This reagent (for example, in the form of KNCS salt) can even detect traces of iron (III) in tap water if it passes through iron pipes coated with rust on the inside.
Iron is the eighth element of the fourth period in the periodic table. Its number in the table (also called atomic) is 26, which corresponds to the number of protons in the nucleus and electrons in the electron shell. It is designated by the first two letters of its Latin equivalent - Fe (Latin Ferrum - read as “ferrum”). Iron is the second most common element in the earth's crust, the percentage is 4.65% (the most common is aluminum, Al). This metal is quite rare in its native form; more often it is mined from mixed ore with nickel.
What is the nature of this connection? Iron as an atom consists of a metallic crystal lattice, which ensures the hardness of compounds containing this element and molecular stability. It is in connection with this that this metal is a typical solid, unlike, for example, mercury.
Iron as a simple substance- a silver-colored metal with properties typical for this group of elements: malleability, metallic luster and ductility. In addition, iron is highly reactive. The latter property is evidenced by the fact that iron corrodes very quickly in the presence of high temperature and corresponding humidity. In pure oxygen, this metal burns well, but if you crush it into very small particles, they will not only burn, but spontaneously ignite.
Often we do not call pure metal iron, but its alloys containing carbon, for example, steel (<2,14% C) и чугун (>2.14% C). Also of great industrial importance are alloys to which alloying metals (nickel, manganese, chromium and others) are added, due to which the steel becomes stainless, i.e. alloyed. Thus, based on this, it becomes clear what extensive industrial applications this metal has.
Characteristics of Fe
Chemical properties of iron
Let's take a closer look at the features of this element.
Properties of a simple substance
- Oxidation in air at high humidity (corrosive process):
4Fe+3O2+6H2O = 4Fe (OH)3 - iron (III) hydroxide (hydroxide)
- Combustion of iron wire in oxygen with the formation of a mixed oxide (it contains an element with both an oxidation state of +2 and an oxidation state of +3):
3Fe+2O2 = Fe3O4 (iron scale). The reaction is possible when heated to 160 ⁰C.
- Interaction with water at high temperatures (600−700 ⁰C):
3Fe+4H2O = Fe3O4+4H2
- Reactions with non-metals:
a) Reaction with halogens (Important! With this interaction, the oxidation state of the element becomes +3)
2Fe+3Cl2 = 2FeCl3 - ferric chloride
b) Reaction with sulfur (Important! With this interaction, the element has an oxidation state of +2)
Iron (III) sulfide - Fe2S3 can be obtained through another reaction:
Fe2O3+ 3H2S=Fe2S3+3H2O
c) Pyrite formation
Fe+2S = FeS2 - pyrite. Pay attention to the oxidation state of the elements that make up this compound: Fe (+2), S (-1).
- Interaction with metal salts located in the electrochemical series of metal activity to the right of Fe:
Fe+CuCl2 = FeCl2+Cu - iron (II) chloride
- Interaction with dilute acids (for example, hydrochloric and sulfuric):
Fe+HBr = FeBr2+H2
Fe+HCl = FeCl2+ H2
Please note that these reactions produce iron with an oxidation state of +2.
- In undiluted acids, which are strong oxidizing agents, the reaction is possible only when heated; in cold acids the metal is passivated:
Fe+H2SO4 (concentrated) = Fe2 (SO4)3+3SO2+6H2O
Fe+6HNO3 = Fe (NO3)3+3NO2+3H2O
- The amphoteric properties of iron appear only when interacting with concentrated alkalis:
Fe+2KOH+2H2O = K2+H2 - potassium tetrahydroxyferrate (II) precipitates.
The process of producing cast iron in a blast furnace
- Roasting and subsequent decomposition of sulfide and carbonate ores (release of metal oxides):
FeS2 —> Fe2O3 (O2, 850 ⁰C, -SO2). This reaction is also the first step in the industrial synthesis of sulfuric acid.
FeCO3 —> Fe2O3 (O2, 550−600 ⁰C, -CO2).
- Burning coke (in excess):
C (coke)+O2 (air) —> CO2 (600−700 ⁰C)
CO2+С (coke) —> 2CO (750−1000 ⁰C)
- Reduction of ore containing oxide with carbon monoxide:
Fe2O3 —> Fe3O4 (CO, -CO2)
Fe3O4 —> FeO (CO, -CO2)
FeO —> Fe (CO, -CO2)
- Carburization of iron (up to 6.7%) and melting of cast iron (melting temperature - 1145 ⁰C)
Fe (solid) + C (coke) -> cast iron. Reaction temperature - 900−1200 ⁰C.
Cast iron always contains cementite (Fe2C) and graphite in the form of grains.
Characteristics of compounds containing Fe
Let's study the features of each connection separately.
Fe3O4
Mixed or double iron oxide, containing an element with an oxidation state of both +2 and +3. Also called Fe3O4 iron oxide. This compound withstands high temperatures. Does not react with water or water vapor. Subject to decomposition by mineral acids. Can be reduced with hydrogen or iron at high temperatures. As you can understand from the above information, it is an intermediate product in the reaction chain of industrial cast iron production.
Iron scale is directly used in the production of mineral-based paints, colored cement and ceramic products. Fe3O4 is what is obtained when steel is blackened and blued. A mixed oxide is obtained by burning iron in air (the reaction is given above). The ore containing oxides is magnetite.
Fe2O3
Iron (III) oxide, trivial name - hematite, a red-brown compound. Resistant to high temperatures. It is not formed in its pure form by the oxidation of iron with atmospheric oxygen. Does not react with water, forms hydrates that precipitate. Reacts poorly with dilute alkalis and acids. It can alloy with oxides of other metals, forming spinels - double oxides.
Red iron ore is used as a raw material in the industrial production of cast iron using the blast furnace method. It also accelerates the reaction, that is, it acts as a catalyst, in the ammonia industry. Used in the same areas as iron oxide. Plus, it was used as a carrier of sound and pictures on magnetic tapes.
FeOH2
Iron(II) hydroxide, a compound that has both acidic and basic properties, the latter predominating, that is, it is amphoteric. A white substance that quickly oxidizes in air and “turns brown” to iron (III) hydroxide. Subject to decomposition when exposed to temperature. It reacts with both weak solutions of acids and alkalis. We will not dissolve in water. In the reaction it acts as a reducing agent. It is an intermediate product in the corrosion reaction.
Detection of Fe2+ and Fe3+ ions (“qualitative” reactions)
Recognition of Fe2+ and Fe3+ ions in aqueous solutions is carried out using complex complex compounds - K3, red blood salt, and K4, yellow blood salt, respectively. In both reactions, a rich blue precipitate is formed with the same quantitative composition, but a different position of iron with valency +2 and +3. This precipitate is also often called Prussian blue or Turnbull blue.
Reaction written in ionic form
Fe2++K++3- K+1Fe+2
Fe3++K++4- K+1Fe+3
A good reagent for detecting Fe3+ is thiocyanate ion (NCS-)
Fe3++ NCS- 3- - these compounds have a bright red (“bloody”) color.
This reagent, for example, potassium thiocyanate (formula - KNCS), allows you to determine even negligible concentrations of iron in solutions. Thus, when examining tap water, he is able to determine whether the pipes are rusty.
Iron is the main structural material. Metal is used literally everywhere - from rockets and submarines to cutlery and wrought iron grill decorations. To a large extent, this is facilitated by an element in nature. However, the real reason is its strength and durability.
In this article we will characterize iron as a metal and indicate its useful physical and chemical properties. Separately, we tell you why iron is called ferrous metal and how it differs from other metals.
Oddly enough, the question of whether iron is a metal or a non-metal still sometimes arises. Iron is an element of group 8, period 4 of D.I. Mendeleev’s table. The molecular weight is 55.8, which is quite high.
This is a silver-gray metal, quite soft, ductile, and has magnetic properties. In fact, pure iron is found and used extremely rarely, since the metal is chemically active and undergoes a variety of reactions.
This video will tell you what iron is:
Concept and features
Iron is usually called an alloy with a small proportion of impurities - up to 0.8%, which retains almost all the properties of the metal. It is not even this option that is widely used, but steel and cast iron. They got their name - ferrous metal, iron, or, more accurately, the same cast iron and steel - thanks to the color of the ore - black.
Today, iron alloys are called ferrous metals: steel, cast iron, ferrite, as well as manganese, and sometimes chromium.
Iron is a very common element. In terms of content in the earth's crust, it ranks 4th, behind oxygen, and. The Earth's core contains 86% of iron, and only 14% is in the mantle. Sea water contains very little of the substance - up to 0.02 mg/l; river water contains slightly more - up to 2 mg/l.
Iron is a typical metal, and also quite active. It reacts with dilute and concentrated acids, but under the influence of very strong oxidizing agents it can form salts of ferric acid. In air, iron quickly becomes covered with an oxide film, preventing further reaction.
However, in the presence of moisture, rust appears instead of an oxide film, which, due to its loose structure, does not prevent further oxidation. This feature, corrosion in the presence of moisture, is the main disadvantage of iron alloys. It is worth noting that impurities provoke corrosion, while chemically pure metal is resistant to water.
Important parameters
Pure metal iron is quite ductile, easily forged and difficult to cast. However, small impurities of carbon significantly increase its hardness and brittleness. This quality became one of the reasons for the displacement of bronze tools by iron ones.
- If we compare iron alloys and, from those that were known in the ancient world, it is obvious that, both in terms of corrosion resistance, and, therefore, in durability. However, the massive scale led to the depletion of tin mines. And, since it is significantly less than , the metallurgists of the past were faced with the question of replacement. And iron replaced bronze. The latter was completely supplanted when steel appeared: bronze does not provide such a combination of hardness and elasticity.
- Iron forms an iron triad with cobalt. The properties of the elements are very close, closer than those of their analogues with the same structure of the outer layer. All metals have excellent mechanical properties: they can be easily processed, rolled, drawn, and can be forged and stamped. Cobalt is both less reactive and more resistant to corrosion than iron. However, the lower abundance of these elements does not allow them to be used as widely as iron.
- The main “competitor” of hardware in terms of area of use is. But in reality, both materials have completely different qualities. It is not nearly as strong as iron, it is less easily drawn out, and cannot be forged. On the other hand, metal is much lighter in weight, which makes the structure much lighter.
The electrical conductivity of iron is very average, while aluminum in this indicator is second only to silver and gold. Iron is ferromagnetic, that is, it retains magnetization in the absence of a magnetic field, and is drawn into a magnetic field.
Such different properties lead to completely different areas of application, so construction materials “fight” very rarely, for example, in furniture production, where the lightness of an aluminum profile is contrasted with the strength of a steel one.
The advantages and disadvantages of iron are discussed below.
Pros and cons
The main advantage of iron compared to other structural metals is its abundance and relative ease of smelting. But, given the amount of iron used, this is a very important factor.
Advantages
The advantages of metal include other qualities.
- Strength and hardness while maintaining elasticity - we are not talking about chemically pure iron, but about alloys. Moreover, these qualities vary quite widely depending on the steel grade, heat treatment method, production method, and so on.
- The variety of steels and ferrites allows you to create and select a material for literally any task - from a bridge frame to a cutting tool. The ability to obtain specified properties by adding very minor impurities is an unusually great advantage.
- The ease of machining makes it possible to obtain products of a wide variety of types: rods, pipes, shaped products, beams, sheet iron, and so on.
- The magnetic properties of iron are such that the metal is the main material in the production of magnetic drives.
- The cost of alloys depends, of course, on the composition, but is still significantly lower than most non-ferrous alloys, albeit with higher strength characteristics.
- The malleability of iron provides the material with very high decorative capabilities.
Flaws
The disadvantages of iron alloys are significant.
- First of all, this is insufficient corrosion resistance. Special types of steel - stainless steel - have this useful quality, but are also much more expensive. Much more often, metal is protected using a coating - metal or polymer.
- Iron is capable of storing electricity, so products made from its alloys are subject to electrochemical corrosion. The housings of instruments and machines, pipelines must be protected in some way - cathodic protection, sacrificial protection, and so on.
- Metal is heavy, so iron structures significantly weigh down the construction object - a building, a railway carriage, a sea vessel.
Composition and structure
Iron exists in 4 different modifications, differing from each other in lattice parameters and structure. The presence of phases is truly crucial for smelting, since it is phase transitions and their dependence on alloying elements that ensure the very flow of metallurgical processes in this world. So, we are talking about the following phases:
- The α phase is stable up to +769 C and has a body-centered cubic lattice. The α phase is ferromagnetic, that is, it retains magnetization in the absence of a magnetic field. A temperature of 769 C is the Curie point for the metal.
- The β-phase exists from +769 C to +917 C. The structure of the modification is the same, but the lattice parameters are slightly different. In this case, almost all physical properties are preserved with the exception of magnetic ones: iron becomes paramagnetic.
- The γ phase appears in the range from +917 to +1394 C. It has a face-centered cubic lattice.
- The δ phase exists above a temperature of +1394 C and has a body-centered cubic lattice.
There is also an ε-modification, which appears at high pressure, as well as as a result of doping with certain elements. The ε phase has a close-packed hexagonal lattice.
This video will tell you about the physical and chemical properties of iron:
Properties and characteristics
Very much depend on its purity. The difference between the properties of chemically pure iron and ordinary technical, and even more so alloy steel, is very significant. As a rule, physical characteristics are given for technical iron with an impurity fraction of 0.8%.
It is necessary to distinguish harmful impurities from alloying additives. The first - sulfur and phosphorus, for example, impart brittleness to the alloy without increasing hardness or mechanical resistance. Carbon in steel increases these parameters, that is, it is a useful component.
- The density of iron (g/cm3) depends to some extent on the phase. Thus, α-Fe has a density of 7.87 g/cubic meter. cm at normal temperature and 7.67 g/cc. cm at +600 C. The density of the γ-phase is lower - 7.59 g/cubic. cm, and the δ-phase is even smaller - 7.409 g/cc.
- The melting point of the substance is +1539 C. Iron is a moderately refractory metal.
- Boiling point – +2862 C.
- Strength, that is, resistance to various types of loads - pressure, tension, bending, is regulated for each grade of steel, cast iron and ferrite, so it is difficult to talk about these indicators in general. Thus, high-speed steel has a bending strength of 2.5–2.8 GPa. And the same parameter of ordinary technical iron is 300 MPa.
- Hardness on the Mohs scale is 4–5. Special steels and chemically pure iron achieve much higher performance.
- Specific electrical resistance 9.7·10-8 ohm·m. Iron conducts current much worse than copper or aluminum.
- Thermal conductivity is also lower than that of these metals and depends on the phase composition. At 25 C it is 74.04 W/(m K), at 1500 C it is 31.8 [W/(m K)].
- Iron is perfectly forged, both at normal and elevated temperatures. Cast iron and steel can be cast.
- A substance cannot be called biologically inert. However, its toxicity is very low. This, however, is connected not so much with the activity of the element, but with the inability of the human body to assimilate it well: the maximum is 20% of the dose received.
Iron cannot be classified as an environmental substance. However, the main harm to the environment is not caused by its waste, since iron rusts quite quickly, but by production waste - slags and gases released.
Production
Iron is a very common element, so it does not require large expenses. Deposits are developed using both open-pit and mine methods. In fact, all mining ores contain iron, but only those where the proportion of metal is large enough are developed. These are rich ores - red, magnetic and brown iron ore with an iron share of up to 74%, ores with an average content - marcasite, for example, and low-grade ores with an iron share of at least 26% - siderite.
The rich ore is immediately sent to the plant. Rocks with medium and low content are enriched.
There are several methods for producing iron alloys. As a rule, the smelting of any steel includes the production of cast iron. It is smelted in a blast furnace at a temperature of 1600 C. The charge - agglomerate, pellets, is loaded together with flux into the furnace and blown with hot air. In this case, the metal melts and the coke burns, which allows you to burn out unwanted impurities and separate the slag.
To produce steel, white cast iron is usually used - in it, carbon is bound into a chemical compound with iron. The most common 3 methods:
- open hearth - molten cast iron with the addition of ore and scrap is smelted at 2000 C in order to reduce the carbon content. Additional ingredients, if any, are added at the end of the melt. This way the highest quality steel is obtained.
- oxygen converter is a more productive method. In the furnace, the thickness of the cast iron is blown with air under a pressure of 26 kg/sq. see. A mixture of oxygen and air or pure oxygen can be used to improve the properties of steel;
- electric melting – more often used to produce special alloy steels. Cast iron is fired in an electric furnace at a temperature of 2200 C.
Steel can also be obtained by the direct method. To do this, pellets with a high iron content are loaded into a shaft furnace and purged with hydrogen at a temperature of 1000 C. The latter reduces iron from the oxide without intermediate steps.
Due to the specifics of ferrous metallurgy, either ore with a certain iron content or finished products - cast iron, steel, ferrite - are sold. Their prices vary greatly. The average cost of iron ore in 2016 – rich, with an element content of more than 60% – is $50 per ton.
The cost of steel depends on many factors, which sometimes makes price rises and falls completely unpredictable. In the fall of 2016, the cost of fittings and hot- and cold-rolled steel increased sharply due to an equally sharp rise in prices for coking coal, an indispensable participant in smelting. In November, European companies offer hot-rolled steel coils at 500 Euro per tonne.
Scope of application
The scope of use of iron and iron alloys is enormous. It is easier to indicate where metal is not used.
- Construction - the construction of all types of frames, from the load-bearing frame of a bridge to the frame of a decorative fireplace in an apartment, cannot do without steel of different grades. Fittings, rods, I-beams, channels, angles, pipes: absolutely all shaped and sectional products are used in construction. The same applies to sheet metal: roofing is made from it, and so on.
- Mechanical engineering - in terms of strength and wear resistance, there is very little that can compare with steel, so the body parts of the vast majority of machines are made of steel. Especially in cases where the equipment must operate under conditions of high temperatures and pressure.
- Tools – with the help of alloying elements and hardening, the metal can be given hardness and strength close to diamonds. High-speed steels are the basis of any machining tools.
- In electrical engineering, the use of iron is more limited, precisely because impurities noticeably worsen its electrical properties, which are already low. But metal is indispensable in the production of magnetic parts of electrical equipment.
- Pipeline - communications of any kind and type are made from steel and cast iron: heating, water supply systems, gas pipelines, including main lines, sheaths for power cables, oil pipelines, and so on. Only steel can withstand such enormous loads and internal pressure.
- Household use – steel is used everywhere: from fittings and cutlery to iron doors and locks. The strength of the metal and wear resistance make it irreplaceable.
Iron and its alloys combine strength, durability and wear resistance. In addition, metal is relatively cheap to produce, which makes it an indispensable material for the modern national economy.
This video will tell you about iron alloys with non-ferrous and heavy ferrous metals:
Iron is a well-known chemical element. It belongs to metals of average chemical activity. We will look at the properties and uses of iron in this article.
Prevalence in nature
There are quite a large number of minerals that contain ferrum. First of all, it is magnetite. It is seventy-two percent iron. Its chemical formula is Fe 3 O 4. This mineral is also called magnetic iron ore. It has a light gray color, sometimes with dark gray, even black, with a metallic sheen. Its largest deposit among the CIS countries is located in the Urals.
The next mineral with a high iron content is hematite - it consists of seventy percent of this element. Its chemical formula is Fe 2 O 3. It is also called red iron ore. It has a color ranging from red-brown to red-gray. The largest deposit in the CIS countries is located in Krivoy Rog.
The third mineral containing ferrum is limonite. Here iron is sixty percent of the total mass. This is a crystalline hydrate, that is, water molecules are woven into its crystal lattice, its chemical formula is Fe 2 O 3 .H 2 O. As the name implies, this mineral has a yellow-brownish color, sometimes brown. It is one of the main components of natural ocher and is used as a pigment. It is also called brown iron ore. The largest locations are Crimea and the Urals.
Siderite, the so-called spar iron ore, contains forty-eight percent ferrum. Its chemical formula is FeCO 3. Its structure is heterogeneous and consists of crystals of different colors connected together: gray, pale green, gray-yellow, brown-yellow, etc.
The last commonly occurring mineral with high ferrum content in nature is pyrite. It has the following chemical formula: FeS 2. It contains iron forty-six percent of the total mass. Thanks to sulfur atoms, this mineral has a golden-yellow color.
Many of the minerals discussed are used to obtain pure iron. In addition, hematite is used in the manufacture of jewelry from natural stones. Pyrite inclusions may be present in lapis lazuli jewelry. In addition, iron is found in nature in living organisms - it is one of the most important components of cells. This microelement must be supplied to the human body in sufficient quantities. The healing properties of iron are largely due to the fact that this chemical element is the basis of hemoglobin. Therefore, the use of ferrum has a good effect on the condition of the blood, and therefore the entire body as a whole.
Iron: physical and chemical properties
Let's look at these two large sections in order. iron is its appearance, density, melting point, etc. That is, all the distinctive features of a substance that are associated with physics. The chemical properties of iron are its ability to react with other compounds. Let's start with the first ones.
Physical properties of iron
In its pure form under normal conditions it is a solid. It has a silver-gray color and a pronounced metallic luster. The mechanical properties of iron include a hardness level of four (medium). Iron has good electrical and thermal conductivity. The last feature can be felt by touching an iron object in a cold room. Because this material conducts heat quickly, it removes most of it from your skin in a short period of time, which is why you feel cold.
If you touch, for example, wood, you will notice that its thermal conductivity is much lower. The physical properties of iron include its melting and boiling points. The first is 1539 degrees Celsius, the second is 2860 degrees Celsius. We can conclude that the characteristic properties of iron are good ductility and fusibility. But that's not all.
Also, the physical properties of iron include its ferromagnetism. What is it? Iron, whose magnetic properties we can observe in practical examples every day, is the only metal that has such a unique distinctive feature. This is explained by the fact that this material is capable of magnetization under the influence of a magnetic field. And after the end of the action of the latter, the iron, the magnetic properties of which have just been formed, remains a magnet for a long time. This phenomenon can be explained by the fact that in the structure of this metal there are many free electrons that are able to move.
From a chemical point of view
This element belongs to the metals of medium activity. But the chemical properties of iron are typical for all other metals (except those that are to the right of hydrogen in the electrochemical series). It is capable of reacting with many classes of substances.
Let's start with simple ones
Ferrum interacts with oxygen, nitrogen, halogens (iodine, bromine, chlorine, fluorine), phosphorus, and carbon. The first thing to consider is reactions with oxygen. When ferrum is burned, its oxides are formed. Depending on the conditions of the reaction and the proportions between the two participants, they can be varied. As an example of this kind of interaction, the following reaction equations can be given: 2Fe + O 2 = 2FeO; 4Fe + 3O 2 = 2Fe 2 O 3; 3Fe + 2O 2 = Fe 3 O 4. And the properties of iron oxide (both physical and chemical) can be varied, depending on its type. These types of reactions occur at high temperatures.
The next thing is interaction with nitrogen. It can also only occur under the condition of heating. If we take six moles of iron and one mole of nitrogen, we get two moles of iron nitride. The reaction equation will look like this: 6Fe + N 2 = 2Fe 3 N.
When interacting with phosphorus, phosphide is formed. To carry out the reaction, the following components are needed: for three moles of ferrum - one mole of phosphorus, as a result, one mole of phosphide is formed. The equation can be written as follows: 3Fe + P = Fe 3 P.
In addition, among reactions with simple substances, interaction with sulfur can also be distinguished. In this case, sulfide can be obtained. The principle by which the process of formation of this substance occurs is similar to those described above. Namely, an addition reaction occurs. All chemical interactions of this kind require special conditions, mainly high temperatures, less often catalysts.
Reactions between iron and halogens are also common in the chemical industry. These are chlorination, bromination, iodination, fluoridation. As is clear from the names of the reactions themselves, this is the process of adding chlorine/bromine/iodine/fluorine atoms to ferrum atoms to form chloride/bromide/iodide/fluoride, respectively. These substances are widely used in various industries. In addition, ferrum is able to combine with silicon at high temperatures. Due to the varied chemical properties of iron, it is often used in the chemical industry.
Ferrum and complex substances
From simple substances we move on to those whose molecules consist of two or more different chemical elements. The first thing to mention is the reaction of ferrum with water. This is where the basic properties of iron appear. When water is heated, it forms together with iron (it is so called because when it interacts with the same water it forms a hydroxide, in other words, a base). So, if you take one mole of both components, substances such as ferrum dioxide and hydrogen are formed in the form of a gas with a pungent odor - also in one to one molar proportions. The equation for this type of reaction can be written as follows: Fe + H 2 O = FeO + H 2. Depending on the proportions in which these two components are mixed, iron di- or trioxide can be obtained. Both of these substances are very common in the chemical industry and are also used in many other industries.
With acids and salts
Since ferrum is located to the left of hydrogen in the electrochemical activity series of metals, it is capable of displacing this element from compounds. An example of this is the displacement reaction that can be observed when iron is added to an acid. For example, if you mix iron and sulfate acid (also known as sulfuric acid) of medium concentration in equal molar proportions, the result is iron (II) sulfate and hydrogen in equal molar proportions. The equation for such a reaction will look like this: Fe + H 2 SO 4 = FeSO 4 + H 2.
When interacting with salts, the reducing properties of iron appear. That is, it can be used to isolate a less active metal from salt. For example, if you take one mole and the same amount of ferrum, you can get iron (II) sulfate and pure copper in the same molar proportions.
Importance for the body
One of the most common chemical elements in the earth's crust is iron. We have already looked at it, now let’s approach it from a biological point of view. Ferrum performs very important functions both at the cellular level and at the level of the whole organism. First of all, iron is the basis of such a protein as hemoglobin. It is necessary for the transport of oxygen through the blood from the lungs to all tissues, organs, to every cell of the body, primarily to the neurons of the brain. Therefore, the beneficial properties of iron cannot be overestimated.
In addition to affecting blood formation, ferrum is also important for the full functioning of the thyroid gland (this requires not only iodine, as some believe). Iron also takes part in intracellular metabolism and regulates immunity. Ferrum is also found in particularly large quantities in liver cells, as it helps neutralize harmful substances. It is also one of the main components of many types of enzymes in our body. A person’s daily diet should contain from ten to twenty milligrams of this microelement.
Iron-rich foods
There are many of them. They are of both plant and animal origin. The first are cereals, legumes, cereals (especially buckwheat), apples, mushrooms (white), dried fruits, rose hips, pears, peaches, avocados, pumpkin, almonds, dates, tomatoes, broccoli, cabbage, blueberries, blackberries, celery, etc. The second ones are liver and meat. Consumption of foods high in iron is especially important during pregnancy, since the body of the developing fetus requires large amounts of this trace element for full growth and development.
Signs of iron deficiency in the body
Symptoms of too little ferrum entering the body are fatigue, constant freezing of hands and feet, depression, brittle hair and nails, decreased intellectual activity, digestive disorders, low performance, and thyroid dysfunction. If you notice several of these symptoms, it may be worth increasing the amount of iron-containing foods in your diet or purchasing vitamins or dietary supplements that contain ferrum. You should also consult a doctor if you feel any of these symptoms too acutely.
Use of ferrum in industry
The uses and properties of iron are closely related. Due to its ferromagnetic nature, it is used to make magnets - both weaker ones for household purposes (souvenir refrigerator magnets, etc.) and stronger ones for industrial purposes. Due to the fact that the metal in question has high strength and hardness, it has been used since ancient times for the manufacture of weapons, armor and other military and household tools. By the way, even in Ancient Egypt, meteorite iron was known, the properties of which are superior to those of ordinary metal. This special iron was also used in Ancient Rome. Elite weapons were made from it. A shield or sword made of meteorite metal could only be owned by a very rich and noble person.
In general, the metal that we are considering in this article is the most versatile among all the substances in this group. First of all, steel and cast iron are made from it, which are used to produce all kinds of products needed both in industry and in everyday life.
Cast iron is an alloy of iron and carbon, in which the latter is present from 1.7 to 4.5 percent. If the second is less than 1.7 percent, then this kind of alloy is called steel. If about 0.02 percent of carbon is present in the composition, then this is already ordinary technical iron. The presence of carbon in the alloy is necessary to give it greater strength, heat resistance, and rust resistance.
In addition, steel may contain many other chemical elements as impurities. This includes manganese, phosphorus, and silicon. Also, chromium, nickel, molybdenum, tungsten and many other chemical elements can be added to this kind of alloy to give it certain qualities. Types of steel containing a large amount of silicon (about four percent) are used as transformer steels. Those containing a lot of manganese (up to twelve to fourteen percent) are used in the manufacture of parts for railways, mills, crushers and other tools, parts of which are subject to rapid abrasion.
Molybdenum is added to the alloy to make it more heat-resistant; such steels are used as tool steels. In addition, to obtain stainless steels, which are well-known and often used in everyday life in the form of knives and other household tools, it is necessary to add chromium, nickel and titanium to the alloy. And in order to obtain impact-resistant, high-strength, ductile steel, it is enough to add vanadium to it. By adding niobium to the composition, high resistance to corrosion and chemically aggressive substances can be achieved.
The mineral magnetite, which was mentioned at the beginning of the article, is needed for the manufacture of hard drives, memory cards and other devices of this type. Due to its magnetic properties, iron can be found in transformers, motors, electronic products, etc. In addition, ferrum can be added to alloys of other metals to give them greater strength and mechanical stability. The sulfate of this element is used in gardening to control pests (along with copper sulfate).
They are indispensable for water purification. In addition, magnetite powder is used in black and white printers. The main use of pyrite is to obtain sulfuric acid from it. This process occurs in laboratory conditions in three stages. In the first stage, ferrum pyrite is burned to produce iron oxide and sulfur dioxide. At the second stage, the conversion of sulfur dioxide into its trioxide occurs with the participation of oxygen. And at the final stage, the resulting substance is passed through in the presence of catalysts, thereby producing sulfuric acid.
Getting iron
This metal is mainly mined from its two main minerals: magnetite and hematite. This is done by reducing iron from its compounds with carbon in the form of coke. This is done in blast furnaces, the temperature in which reaches two thousand degrees Celsius. In addition, there is a method for reducing ferrum with hydrogen. To do this, it is not necessary to have a blast furnace. To implement this method, they take special clay, mix it with crushed ore and treat it with hydrogen in a shaft furnace.
Conclusion
The properties and uses of iron are varied. This is perhaps the most important metal in our lives. Having become known to mankind, it took the place of bronze, which at that time was the main material for the manufacture of all tools, as well as weapons. Steel and cast iron are in many ways superior to the alloy of copper and tin in terms of their physical properties and resistance to mechanical stress.
In addition, iron is more abundant on our planet than many other metals. it is almost five percent in the earth's crust. It is the fourth most abundant chemical element in nature. Also, this chemical element is very important for the normal functioning of the body of animals and plants, primarily because hemoglobin is built on its basis. Iron is an essential trace element, the consumption of which is important for maintaining health and normal functioning of organs. In addition to the above, this is the only metal that has unique magnetic properties. It is impossible to imagine our life without ferrum.
Iron is considered one of the most common metals in the earth's crust after aluminum. Its physical and chemical properties are such that it has excellent electrical conductivity, thermal conductivity and malleability, has a silver-white color and high chemical reactivity to quickly corrode at high humidity or high temperatures. Being in a finely dispersed state, it burns in pure oxygen and spontaneously ignites in air.
The beginning of the history of iron
In the third millennium BC. e. people began to mine and learned to process bronze and copper. They were not widely used due to their high cost. The search for new metal continued. The history of iron began in the first century BC. e. In nature, it can only be found in the form of compounds with oxygen. To obtain pure metal, it is necessary to separate the last element. It took a long time to melt the iron, since it had to be heated to 1539 degrees. And only with the advent of cheese-making furnaces in the first millennium BC did they begin to obtain this metal. At first it was fragile and contained a lot of waste.
With the advent of forges, the quality of iron improved significantly. It was further processed in a blacksmith, where the slag was separated by hammer blows. Forging has become one of the main types of metal processing, and blacksmithing has become an indispensable branch of production. Iron in its pure form is a very soft metal. It is mainly used in an alloy with carbon. This additive enhances the physical property of iron, such as hardness. The cheap material soon penetrated widely into all spheres of human activity and revolutionized the development of society. After all, even in ancient times, iron products were covered with a thick layer of gold. It had a high price compared to the noble metal.
Iron in nature
The lithosphere contains more aluminum than iron. In nature, it can only be found in the form of compounds. Ferric iron, reacting, turns the soil brown and gives the sand a yellowish tint. Iron oxides and sulfides are scattered in the earth's crust, sometimes there are accumulations of minerals, from which the metal is subsequently extracted. The content of ferrous iron in some mineral springs gives the water a special taste.
Rusty water flowing from old water pipes is colored by the trivalent metal. Its atoms are also found in the human body. They are found in hemoglobin (iron-containing protein) in the blood, which supplies the body with oxygen and removes carbon dioxide. Some meteorites contain pure iron, sometimes whole ingots are found.
What physical properties does iron have?
It is a ductile silver-white metal with a grayish tint and a metallic sheen. It is a good conductor of electric current and heat. Due to its ductility, it lends itself perfectly to forging and rolling. Iron does not dissolve in water, but liquefies in mercury, melts at a temperature of 1539 and boils at 2862 degrees Celsius, has a density of 7.9 g/cm³. A peculiarity of the physical properties of iron is that the metal is attracted by a magnet and, after the cancellation of the external magnetic field, retains magnetization. Using these properties, it can be used to make magnets.
Chemical properties
Iron has the following properties:
- in air and water it easily oxidizes, becoming covered with rust;
- in oxygen, the hot wire burns (and scale is formed in the form of iron oxide);
- at a temperature of 700-900 degrees Celsius, it reacts with water vapor;
- when heated, reacts with non-metals (chlorine, sulfur, bromine);
- reacts with dilute acids, resulting in iron salts and hydrogen;
- does not dissolve in alkalis;
- is capable of displacing metals from solutions of their salts (an iron nail in a solution of copper sulfate becomes covered with a red coating - this is the release of copper);
- In concentrated alkalis when boiling, the amphotericity of iron is manifested.
Feature properties
One of the physical properties of iron is ferromagneticity. In practice, the magnetic properties of this material are often encountered. This is the only metal that has such a rare feature.
Under the influence of a magnetic field, iron is magnetized. The metal retains its formed magnetic properties for a long time and remains a magnet itself. This exceptional phenomenon is explained by the fact that the structure of iron contains a large number of free electrons that can move.
Reserves and production
One of the most common elements on earth is iron. In terms of content in the earth's crust, it ranks fourth. There are many known ores that contain it, for example, magnetic and brown iron ore. The metal in industry is obtained mainly from hematite and magnetite ores using the blast furnace process. First, it is reduced with carbon in a furnace at a high temperature of 2000 degrees Celsius.
To do this, iron ore, coke and flux are fed into the blast furnace from above, and a stream of hot air is injected from below. A direct process for obtaining iron is also used. The crushed ore is mixed with special clay to form pellets. Next, they are fired and treated with hydrogen in a shaft furnace, where it is easily restored. They obtain solid iron and then melt it in electric furnaces. Pure metal is reduced from oxides using electrolysis of aqueous salt solutions.
Benefits of Iron
The basic physical properties of the iron substance give it and its alloys the following advantages over other metals:
Flaws
In addition to a large number of positive qualities, there are also a number of negative properties of the metal:
- Products are susceptible to corrosion. To eliminate this undesirable effect, stainless steels are produced by alloying, and in other cases, special anti-corrosion treatment is carried out on structures and parts.
- Iron accumulates static electricity, so products containing it are subject to electrochemical corrosion and also require additional processing.
- The specific gravity of the metal is 7.13 g/cm³. This physical property of iron gives structures and parts increased weight.
Composition and structure
Iron has four crystalline modifications that differ in structure and lattice parameters. For the smelting of alloys, it is the presence of phase transitions and alloying additives that is of significant importance. The following states are distinguished:
- Alpha phase. It lasts up to 769 degrees Celsius. In this state, iron retains the properties of a ferromagnet and has a body-centered cubic lattice.
- Beta phase. Exists at temperatures from 769 to 917 degrees Celsius. It has slightly different lattice parameters than in the first case. All physical properties of iron remain the same, with the exception of magnetic ones, which it loses.
- Gamma phase. The lattice structure becomes face-centered. This phase appears in the range of 917-1394 degrees Celsius.
- Omega phase. This state of the metal appears at temperatures above 1394 degrees Celsius. It differs from the previous one only in the lattice parameters.
Iron is the most sought after metal in the world. More than 90 percent of all metallurgical production falls on it.
Application
People first began to use meteorite iron, which was valued higher than gold. Since then, the scope of this metal has only expanded. The following are the uses of iron based on its physical properties:
- ferromagnetic oxides are used for the production of magnetic materials: industrial installations, refrigerators, souvenirs;
- iron oxides are used as mineral paints;
- ferric chloride is indispensable in amateur radio practice;
- Ferrous sulfates are used in the textile industry;
- magnetic iron oxide is one of the important materials for the production of long-term computer memory devices;
- ultrafine iron powder is used in black and white laser printers;
- the strength of the metal makes it possible to manufacture weapons and armor;
- wear-resistant cast iron can be used to produce brakes, clutch discs, and parts for pumps;
- heat-resistant - for blast furnaces, thermal furnaces, open-hearth furnaces;
- heat-resistant - for compressor equipment, diesel engines;
- high-quality steel is used for gas pipelines, casings of heating boilers, dryers, washing machines and dishwashers.
Conclusion
Iron often means not the metal itself, but its alloy - low-carbon electrical steel. Obtaining pure iron is a rather complex process, and therefore it is used only for the production of magnetic materials. As already noted, the exceptional physical property of the simple substance iron is ferromagnetism, i.e. the ability to be magnetized in the presence of a magnetic field.
The magnetic properties of pure metal are up to 200 times higher than those of technical steel. This property is also affected by the grain size of the metal. The larger the grain, the higher the magnetic properties. Mechanical processing also has an effect to some extent. Such pure iron that meets these requirements is used to produce magnetic materials.