Once magnesium ore has been extracted from the earth, it must go through several processing steps before it can be used in industrial applications. The first step is to crush the ore into small pieces and then heat it in a furnace to remove any impurities. The resulting magnesium oxide is then mixed with a reducing agent, such as ferrosilicon or aluminum, and heated again to produce magnesium metal. This process is known as the Pidgeon process and is the most common method for producing magnesium metal.