Explanation:

All the statements are correct. 

With the total resources of over 31.32 billion tonnes of haematite (Fe2O3) and magnetite (Fe3O4), India is amongst the leading producers of iron ore in the world. Haematite and magnetite are the most important iron ores in India.
Ores carrying very high quantities of hematite or magnetite (greater than ~60% iron) are known as "natural ore" or "direct shipping ore", meaning they can be fed directly into iron-making blast furnaces.
Smelting involves heating up ore until the metal becomes spongy and the chemical compounds in the ore begin to break down. Most important, it releases oxygen from the iron ore, which makes up a high percentage of common iron ores. The most primitive facility used to smelt iron is a bloomery.