There are different raw materials used in making iron. In the manufacturing industry today, iron and steel are the most common materials used for a large variety of applications.
Iron is a lustrous, ductile, malleable, silver-gray metal known to exist in four distinct crystalline forms. It is group VIII of the periodic table.
Today, 90% of all metals are iron, mostly used to manufacture steel. They are often used in civil engineering for reinforced concrete, girders, etc. Well, in this reading, we’ll explore what iron is, its applications, types, properties, raw materials used in making it, and how to make it.
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Related: What is Steel, its Properties and Raw Materials?
What is Iron (FE)?
Iron is a chemical element with the atomic number 26 and the symbol Fe (derived from the Latin ferrum, denoting “iron”). Iron is a member of group 8 and the first transition series of the periodic table.
It constitutes the majority of the planet’s outer and inner core and is, by mass, the most common element on Earth. It is mostly deposited by meteorites in its metallic condition, making it the fourth most prevalent element in the crust of the Earth.
Kilns or furnaces are necessary to extract usable metal from iron ores and may reach 1,500 °C (2,730 °F), which is about 500 °C (932 °F) hotter than what is needed to smelt copper.
Iron is considered the tenth-largest element in the universe and the metal with the greatest abundance on Earth. It is believed that a significant portion of the iron in the Earth contributes to its magnetic field.
Iron is the most abundant element in the Earth, with 5% in the outer crust and high amounts in the inner core.
It is possible that the Earth’s inner core is made up of a single iron crystal, though it is more likely to be a mixture of iron and nickel. A metal that is removed from its magnetic field is iron. Iron is a metal that comes from iron ore, very rarely found in the free state.
Applications
The below explanations are the applications of iron:
Civil engineers use iron to produce steel, which they use to make items like girders and reinforced concrete. Alloy steels, which combine iron with nickel, chromium, vanadium, tungsten, and manganese as additives, are like carbon steels.
The production of rifle barrels, bicycle chains, electric pylons, bridges, and cutting tools uses these products. 3–5% of cast iron is carbon. We use it to make pumps, valves, and pipelines.
The Haber process uses iron catalysts to create ammonia. This metal, as well as its alloys and compounds, can be used to make magnets. Iron is widely used for the production of appliances and utensils, from knives and cutlery to plates and pots.
Electric motors, which power homes, appliances, and industries, also use them. Study everything around you for a moment; you’ll notice that 80–90% of it is iron.
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Properties of Iron
Earth’s inner core is believed to be an iron-nickel alloy with an ε structure, with four allotropes known: α, γ, δ, and ε. The melting and boiling points of iron are lower than earlier 3d elements but higher than manganese due to its half-filled 3d sub-shell.
Magnetic properties of iron include the spontaneous partitioning of atoms into magnetic domains, making objects permanent magnets.
There are four stable isotopes of iron: 54Fe (5.845% of natural iron), 56Fe (91.754%), 57Fe (2.119%), and 58Fe (0.282%). Additionally, scientists have created twenty-four artificial isotopes.
Advances in mass spectrometry have allowed for the detection and quantification of variations in stable isotope ratios of iron, providing insight into the origin and early history of the Solar System.
Iron is the most abundant element in the core of red giants, iron meteorites, and dense metal cores of planets like Earth.
Physical Properties of Iron
Below are the physical properties of iron:
- In moist air it rusts, but not in dry air.
- In diluted acids, it dissolves easily.
- At 1536°C, it melts, and at 2861°C, it boils.
- A metal is magnetic. When this metal is at room temperature, it is present as ferrite or in the α-form.
- It transforms into γ-iron, which is much softer, around 910°C.
Chemical Properties of Iron
The table below shows the chemical properties of iron:
| Group | 8 | Melting point | 1536 °C |
| Period | 4 | Boiling point | 2861 °C |
| Block | d | Density (g cm⁻³) | 7.8 g/cm³ at 20°C |
| Atomic number | 26 | Relative atomic mass | 55.845 |
| State at 20°C | Solid | Key isotopes | 56Fe |
| Electron configuration | [Ar] 3d64s2 | CAS number | 7439-89-6 |
| ChemSpider ID | 22368 | ChemSpider is a free chemical structure database | |
Different Types of Iron Metals
The different types of iron available today are cast iron, wrought iron, white iron, malleable iron, grey iron, and ductile iron.
1. Cast Iron
Smelting iron with carbon, silicon, and other metal alloys produces cast iron. We heat cast iron to a molten state and then pour it into various molds and castings to create various items, including frying pans.
Different processing and heating methods produce a variety of cast iron forms, including gray, white, ductile, and malleable iron.
2. Wrought Iron
Different processing and heating methods produce wrought iron in various forms, including gray, white, ductile, and malleable iron. Wrought iron was one of the first types of iron that blacksmiths produced.
Iron is heated in a furnace to the appropriate temperature in order to make it. Afterwards, the blacksmith uses a hammer to mold the iron into different forms based on the final result.
Reheating wrought iron allows for more bending, shaping, and hammering. Wrought iron, in contrast to other forms of iron, is mostly composed of pure iron with very little carbon and other impurities.
Wrought iron thus becomes incredibly strong. It is ideal for wrought iron fences, gates, and doors because of its strength.
In addition, wrought iron was a common building material used for support beams prior to the invention of steel. These days, doors, gates, railings, and decorative pieces are the primary uses for wrought iron.
3. Malleable Iron
White iron is heated and cooled repeatedly to create malleable iron. Graphite molecules are released into the iron carbide by heating and cooling the iron further. Products made of malleable iron may bend without breaking and have a decent amount of tensile strength.
This iron may be used for a variety of purposes, including as electrical fittings, washers, pipe fittings, tools, farm equipment, and machine parts.
4. Grey Iron
Another type of cast iron is gray iron. The shredded iron contains graphite, which gives it its color. This iron metal has anti-corrosive and wear-resistant properties. Gray iron occasionally replaces wrought iron in outdoor settings.
Related: What are Metals? Thier Properties and Classification
5. Ductile Iron
Ductile iron is another type of cast iron. We add magnesium to the cast iron alloy to create it. Instead of breaking like gray iron does, the addition of magnesium initiates a chemical process that causes the graphite to become spherical.
Ductile iron can be made by varying the amount of magnesium and heat used in production.
6. White Iron
White Iron is another kind of cast iron. We remove the graphite from the cast iron to create it. The white color of iron results from the removal of graphite. White iron is highly malleable while having a respectable level of wear resistance.
Because of this, it is usual practice to use cast iron below the white iron, leaving the white iron just on the outside of the final product.
This goal can be accomplished by allowing the inside of the iron to cool considerably more slowly and solidify as cast iron, while the external surface of the iron is quickly cooled to remove the graphite.
Raw Materials used in Making iron
The basic raw materials for making iron are iron ore, coke, limestone, and sinter.
1. Iron ore
Iron ore is one of the basic raw materials, among others, used in the production of iron. It is described as any mineral substance that contains enough iron to make its smelting a viable proposition, i.e., an iron content of less than 20%.
Ores vary considerably in form and composition from one source to another. Some ores are naturally found as very hard rock, some as granular masses, and some as loose, earthy materials with color variations from black to brick red.
The ore contains iron as a chemical compound, typically in the form of an oxide. Generally, we smelt these ores, which contain iron oxide materials such as magnetite, hematite, and limonite.
Magnetite ores are the richest known, with around 65% iron. It is a ferrosoferric oxide (Fe₃O₄); That is, black, dense, and strongly magnetic.
2. Coke:
Coke plays three important roles in the blast furnace during the production of iron. It serves as fuel to provide heat for smelting, as a rich source of carbon monoxide gas into iron, and as non-clogging support for the burden (the charge) in the blast furnace.
Its porosity aids the free passage of the gas through the furnace. It is made by roasting specially selected coking coal in large sealed ovens.
Volatile substances are produced whilst the gases released are cleaned and used as fuel in other parts of the plant. Coke, as one of the raw materials used in ironmaking, is a substance made by heating coal until it becomes almost pure carbon.
Related: What is Sheet Metal? its Types, Sizes & Forming Processes
3. Limestone
Limestone serves as a fluxing agent with the extraneous materials (‘gangue’) associated with the ore. It combines with these materials (clay, etc.) and makes them more readily fusible, forming a liquid slag that separates from the iron.
4. Sinter
Sinter is made of laser-grade, finely divided iron ore that is roasted with coke and lime and enables it to remove a large number of impurities in the ore.
Some other metals, such as chromium, nickel, manganese, molybdenum, tungsten, etc. Are sometimes mixed with iron for the production of various steels.
How to Make Iron?
Skilled workers in the charging house created pig iron, a product of the blast furnace process. These workers ensured that the blast furnaces, large ovens used to cook the iron mixture, received the correct amounts of ingredients.
The ingredients for pig iron included limestone, ironstone, coke, and air.
The iron ore was roasted in calcining kilns to remove impurities, and the air was blown into the blast furnace by powerful steam engines. We added limestone as a flux, allowing it to combine with the impurities in the iron ore.
We heated the mixture for the required period and removed the slag from the blast furnaces. We then allowed the molten iron to flow into prepared sand beds, known as pig beds, and set it there.
Pig iron was then taken to refineries, forges, and rolling mills. We used two blast refineries to burn out impurities before puddling. A cistern or water trough cooled the metal after refining.
The forge initially used helve hammers, chaferies, and fineries for refining iron. However, this method became unprofitable, leading to the installation of a steam engine, puddling furnaces, and two new hammers. In 1810, the engines provided power to work 3 shingling hammers and one drawing hammer. The forge had 10 puddling furnaces, 2 ball furnaces, and one chafer.
Refineries brought iron to the forge, where it underwent rework in puddling furnaces, reheating in balling furnaces, hammering, and drawing for rolling mills. The forge used wheelbarrows, carriages, and 14 water boxes for cooling working tools.