Cochise College           Student Papers in Geology

Geology Home Page                   physical geology  historical geology           

Roger Weller, geology instructor            regional geology  planetary  gems

wellerr@cochise.edu


Iron
Suzanne Uliasz
Physical geology
Fall 2008
 

 

                               From Meteorites to Iron to Steel

It is believed Iron was first used around 4000 BC by the Egyptians and Sumerians.  It is believed they made iron from meteorites that fell from Mars. There are many different kinds of meteorites that fall from Mars, and below are a few samples.










 




                                           Hematite

 

















                                           

                                              
                                                Goethite











 


 


                                                   
                                          limonite






















                                             magnetite
 

Materials made from this iron were daggers, ornaments, and spear tips. During the Iron Age, iron was the predominant metal used for weapons and tools.



















 


Hook, axe-heads, and spearheads

 

Eventually, carbon was added to the iron and wrought iron was produced with this mixture, and it had a hard steel surface, and so it was the most favored mineral to use and was more precious than bronze.

















                     wrought-Iron gate

 

Items were also made from cast iron from the 15th century. This was iron and carbon, which was melted and poured into moulds. Cast iron pots and pans are still popular today because it is very strong and distributes heat evenly. The same is true of cast iron heaters.









 


 




cast iron heater
 

In the middle 1900s ironmaking was carried out in many parts of the world and had become the most important metal. However, the Iron Age could not last forever and eventually the Industrial Age took over and with it a way to make steel, which was harder and stronger than iron.

Using a process where an iron alloy called spiegeleisen, which contained manganese, removed the oxygen from the steel. Later, two English chemists also discovered that adding limestone to the converter would remove most of the sulfur and the phosphorus. Eventually, adding different combinations of minerals to the iron ore produced different kinds of steel, such as carbon steel, and chromium steel.

Hematite, one of the iron ores used to process steel, is the most sought after because it contains 66% iron. Pig iron, which is one of the main raw materials to make steel, comes from iron ore.

Shown below is a picture of Hematite, and pellets of iron ore waiting to be made into steel.

 

 

 

 

 

  













                                          hematite

 















                             Heap of iron ore
pellets 

 

 

 

Cited Works

Intro to Iron

AIRMET- Metalworks. Fabricators of Exquisite Decorative Wrought Iron Fence, Cus…

Steel- Raw Materials, Manufacturing Processes, /quality Control, Byproducts/waste,…

Iron Ore- Wikipedia

Cast iron Stock Photos/ Pictures/ Photography, Royalty Free Images at Inmagine

Mineral Information Institute- IRON ORE