What is Iron Ore? How Did It Form?

You might think of iron ore as one of the main commodities traded globally, but our history of iron ore predates all modern financial markets by several years. Humans have been using iron in various capacities since as early as 3200 BC. However, iron production did not become widespread in ancient Mesopotamia until around 1200 BC.

1. What is iron ore?

Iron ore is a mineral from which metallic iron can be extracted when heated in the presence of a reducing agent such as coke. Iron deposits are found in sedimentary rocks, which are essentially rocks that have formed over time from the accumulation of different sediments. The two most important minerals extracted from iron ore are the iron oxides hematite and magnetite. These two iron oxides are used to produce almost any steel object you can image.

2. How is iron ore formed?

Almost all of the major iron ore deposits on our planet exist in rocks that formed about 2 billion years ago. At that time, large amounts of dissolved iron could be found in oceans with little dissolved oxygen. Iron ore did not begin to form deposits until the first organisms capable of photosynthesis appeared. When these organisms release oxygen into the water, it combines with dissolved iron to produce hematite and magnetite. These minerals then accumulated on the seafloor, now known as banded iron formations. As the name suggests, Banded Iron Formation, or BIF for short, is a term used to describe a unique formation of sedimentary rock that is thin banded. The different colors contrast with each other and look similar to a rainbow.

3. What is iron ore used for? How to mine?

The vast majority of iron ore is used to produce iron, which in turn is used to produce steel. 98% of the iron ore mined today is used in steel production. This includes staples for construction, cars and steel beams, and pretty much anything that requires steel. Iron ore is usually located near the earth's surface, so it is usually mined using blasting and removal techniques in large open pit mines. Surface soil and rock, also known as overburden, are dug away to obtain iron ore. The rock is blasted with explosives and the remnants are placed in a large dump truck that can hold hundreds of tons. These trucks carry the rock out of the open pit, usually loading the ore onto trains. The rock is then transported by rail to processing plants to produce iron and ultimately steel.