MMForum: Metallurgy, From Previous Until Now
Metallurgy is a branch of science that learns about how to produce metal. Metallurgy has existed since prehistoric age. At that time, egyptian succeeded to produce iron but safety of workers is still not considered because knowledge about metallurgy is very limited. People only focused on how to produce iron which would be used for tools later. Along with the development of technology, people start to think of how to produce metal using safer and more profitable methods. In class, I have learned how a new technology could replace the old one. Egyptian smelting has transformed into charcoal furnace and into blast furnace afterwards.
In egyptian smelting, iron ore and charcoal were put on the ground and air was blown with blowpipe. The reaction between those materials produced molten iron and rose the temperature until about 1500 degrees celcius. Egyptian smelting is not a safe process because there is no barrier between workers and molten iron. Imagine how if your skin is splashed with 1500 degrees celcius molten iron. Besides, carbon monoxide which is released to the atmosphere can kill for those who inhale it.
In order to overcome the problem, people began to use charcoal furnace, a semi automated furnace, to produce iron. The principle of charcoal furnace is similar to that of egyptian smelting. The reaction in egyptian smelting took place on the ground while in charcoal furnace it took place inside the furnace. The furnace functions as a barrier to protect workers from the hot metal, molten iron which is tapped from the furnace. However, this technology still shares dangerous downside with its egyptian predecessor: the lethal fume of carbon monoxide. Besides, charcoal furnace lining is very thick which means higher invesment cost.
Blast furnace came to replace charcoal furnace. Blast furnace, a fully-automated furnace to produce iron, offers safer and more profitable iron making method. This technology has been applied in most iron making industries such as ArcelorMittal, Nippon Steel and PT. Indoferro. In blast furnace, hot metal and slag are transfered with torpedo car, raw materials are fed with conveyor belt, off gas is cleaned before it is released to the atmosphere. These features give workers no direct contact with the furnace, thus provide them with protection from hot metal and the toxic carbon monoxide gas. Further transformation of blast furnace from age to age gives more advantages. Oxygen-enriched air is used to gives more efficient process because higher oxygen content gives more heat efficiency. Blast furnace refractory and lining is thinner than charcoal furnace’s so the invesment cost is lower. Reduction of coke consumption in blast furnace also gives lower operation cost.
The conclusion is all development which has been done from previous until now, from egyptian smelting until blast furnace aims to produce metal using safe and profitable methods. Because of that, I hope someday I can make a new technology or improve today’s technology to produce metal using safer and more profitable methods and also useful for many people.
Scheel, Bernd. Egyptian Metalworking and Tools. Aylesbury : Shire Publications LTD, 1989. E-book.
Zulhan, Zulfiadi. Pyrometallurgy. 2012. Lecture slide.
How A Blast Furnace Works http://www.steel.org/Making%20Steel/How%20Its%20Made/Processes/How%20A%20Blast%20Furnace%20Works%20larry%20says%20to%20delete.aspx (Accessed 2014-25-06)