Question

What type of ores are concentrated by magnetic separation techinique?

What type of ores can be concentrated by magnetic separation technique? Describe the process.

Answer 1

Magnetic separation technique is used when the ore particles are attracted by a magnet but the gangue is not. For example, haematite (Fe₂O₃), an ore of iron, is concentrated by this method. The magnetic ore particles are separated from the non-magnetic silicious gangue.

As shown in the figure, this method involves causing powdered ore to fall onto a rubber belt that moves horizontally over two rollers, one of which is magnetic.

While the non-magnetic gangue particles fly off and gather in a heap distant from the magnetic roller, the magnetic ore particles are drawn to it and fall closer to it.

This method can also be used to separate magnetic impurities from non-magnetic mineral particles. In this instance, the non-magnetic ore particles fall farther away, while the magnetic gangue particles gather close to the magnetic roller. For instance, this technique can be used to concentrate wolframite, a non-magnetic tungsten ore that contains magnetic iron impurities.