When do we use magnetic separation method for concentration of an ore ? Explain with an example

Magnetic separation : If the ore or impurity one of them is magnetic and the other non-magnetic then they are separated using electromagnets.
Ex : Some ores are attracted by a magnet whereas gangue is not attracted. The magnetic ores like iron pyrites FeS and magnetite are concentrated by this method as shown below in figure. The crushed ore is allowed to pass through electromagnetic belts. The mineral particles are retained and gangue particles are thrown away.