Iron

byJohn Greerty

Iron, like our furry Iron man, is strong, durable, and useful. Iron is one of the world’s cheapest and most useful metals. Iron and steel are hard metals used in making thousands of products, from paper clips to automobiles and machines. Iron can refer to both an element and a number of alloys, or iron and other metallic elements. As an element, iron is one of the most common chemical substances on earth. While it is never found in pure form, it is almost always found in a ore. These alloys produce iron products, such as steel, by refining the iron, then alloying it with other metals. Iron ores are mineral or rock deposits in which iron was concentrated by natural forces during the formation of the earth’s crust. Metallic iron is then used in making steel and other iron products through heating and melting. These metals we call iron and steel are alloys of the element iron.

In nature iron always occurs in chemical combination with other elements, especially oxygen, carbon, sulfur, and silicon. The atomic number of iron is 26. The atomic mass of iron is 55.847. The many kinds of iron ores therefore contain chemical compounds made up of iron and one or more elements. The principal ores from which iron is obtained include hematite, magnetite, limonite, pyrite, siderite, and taconite. The world’s largest deposites of iron ores were formed by a process that began more than 2 million years ago. It took place in areas covered by shallow seas. Iron compounds gradually settle on the bottom of the seas. Together with sand and silt that formed into rock. Earthquakes and the shrinking of the earth’s crust raised the rock above the level of the water. As water trickled through the rock, rich deposits of ore were left, washing away the sand. Other ways of forming ore deposits should also be noted; slow cooling of molten volcanic rock produced iron ore, and tiny organisms in water have also caused iron oxide. Today iron oxides are also found in marshy areas and on beaches. Today, major deposits of iron ore are found near Lake Superior in Minnesota and Michigan, the Mesabi Range in Minnesota has produced more iron ore than any other area in the U.S. California, Australia, Brazil, Russia, and Venezuela.

Two basic methods of mining iron ore are the open pit method and underground mining. However, the use of iron goes back to prehistoric people who made tools and weapons from iron. The Hittites by about 1400 BC made iron harder, and what we know as the Iron age was under way. Today, iron ore is made into metallic iron in a blast furnace where it is melted , or a direct reduction system where it produces solid iron. More than 90 percent of the iron produced in blast furnaces is used in making steel. The rest is cast into pigs and shipped to plants called foundries, where it is made into cast iron and wrought iron. Steelmaking is one of the world’s most useful industries. Steel, an alloy of iron and carbon undergo great changes in it’s physical properties through heating and working the metals.