Main Difference – Magnetite vs Hematite
A mineral deposit is a naturally occurring deposit that is unusually rich with a particular mineral. If a mineral deposit is composed of a metal that can be extracted using existing technological methods, then it is called an ore. Magnetite and hematite are two forms of iron ores from which iron can be extracted. Magnetite contains iron in the form of Fe3O4. Hematite contains iron in the form of Fe2O3. The main difference between magnetite and hematite is that magnetite is ferromagnetic whereas hematite is paramagnetic.
Key Areas Covered
1. What is Magnetite
– Definition, Chemical and Physical Properties
2. What is Hematite
– Definition, Chemical and Physical Properties
3. How to Separate Magnetite from Hematite
– Induced Roll Magnetic Separator
4. What is the Difference Between Magnetite and Hematite
– Comparison of Key Differences
Key Terms: Crystal System, Ferromagnetic, Hematite, Iron, Magnetite, Ore, Paramagnetic
What is Magnetite
Magnetite is an iron ore where iron can be found in the form of Fe3O4. Magnetite is ferromagnetic, which means, magnetite particles are attracted to an external magnetic field; magnetite particles can act like tiny magnets when magnetized.
Magnetite is ferromagnetic since it has both Fe2+ and Fe3+ ions that have many unpaired electrons. The presence of unpaired electrons causes the magnetic properties of minerals.
- The electron configuration of Fe2+ is 1s2 2s2 2p6 3s2 3p6 3d6 where 4 unpaired electrons are present.
- The electron configuration of Fe3+ is 1s2 2s2 2p6 3s2 3p6 3d5 where 5 unpaired electrons are present.
Therefore, magnetite can be separated from a mixture using low-intensity magnetic separation because magnetite particles can get attracted even to a magnetic field with a low intensity of 0.04 Tesla.
Figure 1: Appearance of Magnetite
Magnetite has a black to gray color. The streak of magnetite is black. The streak of a mineral is the color of the mineral when it is finely powdered. Magnetite is an opaque mineral (not transparent). It is mainly found in sedimentary rocks. But it is sometimes found in beach sand in large quantities.
The major use of magnetite is as a source to extract iron in the form of pig iron or sponge iron form. This produced iron is further used to convert into steel. In addition, magnetite is used as a catalyst. It is the catalyst used in the production of ammonia in industrial scale.
What is Hematite
Hematite is an iron ore where iron can be found in the form of Fe2O3. It is a major source of extracting iron. Hematite is a paramagnetic mineral. Therefore, it can get attracted to an external magnetic field. Hematite is widely spread in rocks and soil.
Figure 2: Hematite (in gray color) with Quartz (in white color).
Hematite has unpaired electrons that cause its magnetic properties. It is paramagnetic because it has only ferric ion (Fe3+). The electron configuration of Fe3+ is 1s2 2s2 2p6 3s2 3p6 3d5 where 5 unpaired electrons are present. Therefore, hematite can be separated from a mixture using high-intensity magnetic separation methods which use magnetic fields with intensity ranging from 0.02-4.0 Tesla. Hematite has a metallic gray appearance. But the streak of hematite is red to reddish brown. It is an opaque material.
How to Separate Magnetite from Hematite
Magnetite and hematite can be separated from each other using their magnetic properties. Magnetite is ferromagnetic and hematite is paramagnetic. Therefore, these substances can be separated using low-intensity magnetic separation method. Here, an induced roll magnetic separator with a magnetic field with a 0.04 Tesla intensity is used.
Figure 3: Magnetic Separation of Magnetite and Hematite
The above diagram shows how the separation is done by a magnetic separator. In this method, the mixture of magnetite and hematite is fed to the separator from the top. The magnetite particles are pinned on to the induced roll, but hematite particles do not get pinned because the low-intensity magnetic field here is not sufficient for hematite particles to pin on to the roll. Therefore, the hematite particles freely fall into a container. The pinned particles are collected by removing them from the roll using a brush.
Difference Between Magnetite and Hematite
Definition
Magnetite: Magnetite is an iron ore where iron can be found in the form of Fe3O4.
Hematite: Hematite is an iron ore where iron can be found in the form of Fe2O3.
Presence of Iron
Magnetite: In magnetite, iron is present in the form of Fe2+ and Fe3+.
Hematite: In hematite, iron is present in the form of Fe3+.
Magnetic Properties
Magnetite: Magnetite is ferromagnetic.
Hematite: Hematite is paramagnetic.
Separation
Magnetite: Magnetite can be separated from a mixture using low-intensity magnetic separators.
Hematite: Hematite can be separated from a mixture using high-intensity magnetic separators.
Appearance
Magnetite: Magnetite has a black to gray color.
Hematite: Hematite has a metallic gray appearance.
Mineral Streak
Magnetite: The streak of magnetite is black
Hematite: The streak of hematite is red to reddish brown
Conclusion
Magnetite and hematite are important minerals that can be used as sources for extraction of iron. The main difference between magnetite and hematite is that magnetite is ferromagnetic whereas hematite is paramagnetic.
Reference:
1. “Magnetite.” Wikipedia, Wikimedia Foundation, 24 Jan. 2018, Available here.
2. “Minerals.net.” Hematite, Available here.
3. “Hematite.” Wikipedia, Wikimedia Foundation, 24 Jan. 2018, Available here.
Image Courtesy:
1. “Magnetite-118736” By Rob Lavinsky, iRocks.com (CC-BY-SA-3.0) via Commons Wikimedia
2. “Quartz-Hematite-244282” By Rob Lavinsky, iRocks.com (CC BY-SA 3.0) via Commons Wikimedia
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