The magnetization o magnetic separation is a process that takes advantage of the magnetic characteristics of some substances to separate different solids. For example: In mining, magnetization allows iron and other metals to be separated from coal.
The magnetism It is a physical phenomenon by which objects exert forces of attraction or repulsion. All materials are affected by magnetic fields, however, some are influenced to a greater extent than others.
Materials with metallic properties they are attracted to magnets. For this reason, when small portions of metals are scattered between another material, they can be separated thanks to the magnetization.
Everything magnetic field it has a specific intensity. Intensity is given by the number of lines of flow that pass through a unit area. Every magnet has a stronger magnetic field the closer to its surface we are. The field gradient is the speed at which that intensity increases towards the magnetic surface.
The power of a magnet is its ability to attract a mineral. It depends on its field strength and its field gradient.
Types of minerals
The minerals They are classified according to their magnetic susceptibility in:
- Paramagnetic. They become magnetized by the application of a magnetic field. If there is no field, then there is no magnetization. That is, paramagnetic materials are materials attracted to magnets, but they do not become permanently magnetized materials. They are extracted with high intensity magnetic separators.
- Ferromagnetic. They experience high magnetization when a magnetic field is applied and remain magnetized even when the magnetic field is not present. They are extracted with low intensity magnetic separators.
- Diamagnetic. They repel the magnetic field. They cannot be pulled out magnetically.
Examples of magnetization
- Car recycling. Cars are made of different materials. When they are discarded, they are crushed and then, thanks to a powerful magnet, only the metallic materials are extracted, which can be recycled.
- Iron and sulfur. Iron can be extracted from the mixture with sulfur thanks to magnetization.
- Conveyor belts. Magnetic plates are used to separate ferrous (iron-containing) materials in material streams on conveyor belts or ramps.
- Magnetic grids. The installation of magnetic grids in pipes and channels makes it possible to extract all the metallic particles that circulate in the water.
- Mining. Magnetization allows iron and other metals to be separated from carbon.
- Sand. Extract iron filings scattered throughout the sand.
- Water cleaning. Magnetization allows the removal of ferrous minerals from water flows, avoiding contamination.
Other techniques for separating mixtures
- Crystallization
- Distillation
- Chromatography
- Centrifugation
- Decantation