Answer:
The iron ore deposits began forming when the first organisms capable of photosynthesis began releasing oxygen into the waters. This oxygen immediately combined with the abundant dissolved iron to produce hematite or magnetite. ... Steel Mill: Most iron ore is used to make steel.
The metal is obtained by reducing the oxide with sodium, magnesium or aluminium, or by the electrolysis of manganese sulfate. Manganese nodules have been found on the floor of the oceans. These nodules contain about 24% manganese, along with smaller amounts of many other elements.