Iron Ores (Hematite and Magnetite)

Iron is a metal from the periodic table’s first transition series and group 8. It is the most common element on Earth by mass, just ahead of oxygen (32.1 % and 30.1 %, respectively), forming much of the Earth’s outer and inner cores. It is the fourth most abundant element in the crust of the Earth.

The chemical symbol for iron is Fe, and the atomic number is 26.

Iron in its metallic state is extremely rare in the Earth’s crust, owing primarily to meteorite deposition. Iron ores, on the other hand, are among the most abundant in the Earth’s crust, but extracting usable metal from them necessitates the use of kilns or furnaces capable of reaching 1,500 °C or higher, which is about 500°C higher than the temperature required to smelt copper. Due to their mechanical properties and low cost, iron alloys such as steel, stainless steel, cast iron, and special steels are by far the most common industrial metals in the modern world.

Iron as Heavy Metal

Iron is notable for being the final element produced by stellar nucleosynthesis, and thus the heaviest element that does not require the formation of a supernova or other cataclysmic event. As a result, it is the most abundant heavy metal in the universe. Iron is a metal that has been extracted due to its magnetic field. Iron is a metal extracted from iron ore that is rarely found in its natural state. Iron is used in the production of steel, which is not an element but an alloy of various metals and some nonmetals, most notably carbon.

Physical Properties of Iron are:

1. It rusts in moist air but not in dry air.
2. It dissolves easily in weak acids.
3. This metal is in the form of ferrite or α-form at room temperature.
4. It changes to α-iron at 910°C, which is much softer in nature.
5. It has extremely high melting and boiling point.
6. Because it is a metal, it is magnetic in nature.

Uses of Iron are:

• It is used in the production of steel as well as in civil engineering applications such as reinforced concrete, girders, and so on.
• Alloy steels, such as carbon steels, are made with iron and additives such as nickel, chromium, vanadium, tungsten, and manganese.
• Bridges, electricity pylons, bicycle chains, cutting tools, and rifle barrels are all made from these.
• Carbon is present in 3–5% of cast iron. It is used in the manufacture of pipes, valves, and pumps.
• In the Haber process, iron catalysts are used to produce ammonia.
• This metal, as well as its alloys and compounds, can be used to make magnets.

Ores of Iron

A mineral deposit is a naturally occurring deposit that contains an unusually high concentration of a specific mineral. An ore is a mineral deposit that contains a metal that can be extracted using existing technological methods. Iron can be extracted from two types of iron ores: Magnetite and hematite. 

Magnetite is composed of iron in the form of Fe₃O₄. Hematite is a mineral that contains iron in the form of Fe₂O₃. The primary distinction between magnetite and hematite is that magnetite is ferromagnetic and hematite is paramagnetic.

Magnetite

Magnetite is an iron ore that contains iron in the form of Fe₃O₄. Magnetite is ferromagnetic, which means that magnetite particles are attracted to an external magnetic field; when magnetized, magnetite particles can act like tiny magnets. Magnetite is ferromagnetic because it contains both Fe⁺² and Fe⁺³ ions, both of which have many unpaired electrons. Minerals’ magnetic properties are caused by the presence of unpaired electrons. Magnetite can thus be separated from a mixture using low-intensity magnetic separation because magnetite particles are attracted to magnetic fields as weak as 0.04 Tesla.

Magnetite is a black to grey mineral. The magnetite streak is black. A mineral’s streak is the colour of the mineral when finely powdered. Magnetite is a mineral that is transparent (not transparent). It is found primarily in sedimentary rocks. However, it is occasionally found in large quantities in beach sand.

Magnetite is primarily used to extract iron in the form of pig iron or sponge iron. This produced iron is then used to make steel. Magnetite is also used as a catalyst. It is the catalyst used in the industrial-scale production of ammonia. Magnetite is primarily used to extract iron in the form of pig iron or sponge iron. This produced iron is then used to make steel. Magnetite is also used as a catalyst. It is the catalyst used in the production of ammonia on an industrial scale.

Hematite

Hematite is an iron ore that contains iron in the form of Fe₂O₃. It is a significant source of iron extraction. Hematite is a mineral that is paramagnetic. As a result, it can be drawn to an external magnetic field. Hematite is abundant in rocks and soil.

Hematite’s magnetic properties are caused by unpaired electrons. It is paramagnetic due to the presence of only ferric ion (Fe⁺³). As a result, hematite can be separated from a mixture using high-intensity magnetic separation methods that employ magnetic fields ranging in intensity from 0.02-4.0 Tesla. Hematite is a metallic grey mineral. The hematite streak, on the other hand, is red to reddish brown. It is an opaque material.

Separating Magnetite from Hematite

The magnetic properties of magnetite and hematite can be used to separate them. Magnetite is a ferromagnetic mineral, whereas hematite is a paramagnetic mineral. As a result, these materials can be separated using a low-intensity magnetic separation method. An induced roll magnetic separator is used in this application. 

The magnetite and hematite mixture is fed to the separator from the top in this method. Magnetite particles are pinned to the induced roll, but hematite particles are not pinned because the low-intensity magnetic field here is insufficient to pin hematite particles to the roll. As a result, the hematite particles fall freely into a container. The pinned particles are collected by brushing them off the roll.

Sample Questions

Question 1: Why does iron have a high melting point?

Answer:

To melt or boil a metal, the attraction between metal ions and dislocated electrons must be overcome. Because such attractive forces are solid, metals have high melting and boiling points.

Question 2: What are the types of iron?

Answer:

They include plain iron, wrought iron, cast iron, pig iron, and direct reduced iron. Pure iron is a term used to describe fresh iron produced in an electric arc furnace at temperatures high enough to melt the iron.

Question 3: How is magnetite separated from hematite?

Answer:

The magnetic properties of magnetite and hematite can be used to separate them. Magnetite is a ferromagnetic mineral, whereas hematite is a paramagnetic mineral. As a result, these materials can be separated using a low-intensity magnetic separation method.

Question 4: What are the properties of magnetite?

Answer:

Magnetite is a black to grey mineral. The magnetite streak is black. A mineral’s streak is the colour of the mineral when finely powdered. Magnetite is a mineral that is transparent (not transparent). It is found primarily in sedimentary rocks. However, it is occasionally found in large quantities in beach sand.

Question 5: What is an ore?

Answer:

A mineral deposit is a naturally occurring deposit that contains an unusually high concentration of a specific mineral. An ore is a mineral deposit that contains a metal that can be extracted using existing technological methods.