Iron

Iron (Fe, from the Latin ferrum) is a chemical element and metal with atomic number 26. It is one of the most abundant metals found on Earth, particularly in the crust and core. Pure iron is a hard, shiny metal, but when exposed to air and moisture it forms a red oxide known as rust.

Iron plays a major role in modern industry. It is rarely used in pure form; instead it is made into alloys such as steel (bir-xoogeed), which is iron with a small amount of carbon added. Iron is also part of living organisms: it is found in hemoglobin in the blood, where it carries oxygen.

Physical and Chemical Properties

Iron is a hard and malleable metal, and it conducts electricity and heat. It has a special property called magnetism: at normal temperatures, iron responds to magnetic fields and can become permanently magnetized. When temperature rises sufficiently, it loses this property. Chemically, iron reacts readily with oxygen, producing iron oxide (rust) which does not adhere to the underlying surface and therefore continues to penetrate inward.

Extraction and Refining

Iron is extracted from ores such as hematite and magnetite. The standard process involves loading ore into a large blast furnace along with coke and limestone. Heat and carbon remove the oxygen from the ore, and the result is molten iron that flows to the bottom. This raw iron contains a high amount of carbon, which is reduced when steel is desired.

History

The use of iron began after copper and bronze. The period in history called the Iron Age marks a stage when various societies began to make weapons and farm tools from iron instead of bronze. During the industrial revolutions of later centuries, iron and steel production became the foundation for railroads, ships, and large construction.