Metallurgy
Definition of Metallurgy
Metallurgy is "the science and study of the behaviors and properties of metals” (Tom Bertone Consulting, 2012) and the procedures involved in the extraction of metal from ore. In particular, it deals with the properties of metals and alloys.
Metals are characterized as having the capability of conducting electricity and heat (“Metallurgy,” 2011). They are hard and are dense under room temperature. Alloys, on the other hand, are combinations of metals. An example of an alloy is steel, which is a combination of carbon and iron, although vanadium and chromium may also be added. Other examples of alloy are brass, which is composed of zinc and copper, and bronze, which is composed of tin and copper.
Metallurgy is concerned with the manner by which metals and metallic compounds are used in different applications such as architecture, structural engineering, and electronics.
Brief History of Metallurgy
Evidence shows that the science of metallurgy began some 6,500 years ago, with meteoric iron, silver, tin, and copper being used by Egyptians for making weapons. Throughout the different ancient cultures, these metals underwent various forms of metalworking processes.
It was during the Bronze Age, which began at around 3500 BC, when “the first evidence of a standard metallurgy technology appeared” (WiseGeek, n.d.). It was during this time when the discovery was made that the heating and combination of tin and copper would result in the creation of a bronze alloy.
At around 1200 BC, during the Iron Age, the Hittites made the discovery of extracting iron from ore, which they used for the advancement of their culture.
Metallurgy enabled the advancement of the human race from simple stone work to complex mechanisms that eventually made way for the Industrial Revolution. Whereas the methods of heat treating and steel making were discovered through trial and error in ancient times where the information had to be passed down from generation to generation, the Industrial Revolution has made the annual production of 150 million tons of steel in the U.S.A. possible.
Relevance of Metallurgy
Metals in their native and pure forms are too soft to be used for industrial purposes. This is the reason that metallurgy focuses on the production of alloys. Metallurgical engineers then perform different types of metal testing in order to form measurable assumptions about the strength of a metal. The tests are intended to determine the properties of metals to ensure their strength and sturdiness. When parts fail then it becomes the metallurgical engineer’s responsibility to determine the cause of failure.
Most of the present-day needs of civilization are dependent on metals. Large amounts of nickel alloy, copper, titanium, aluminum, and steel are used for buildings, bridges, spacecraft, aircraft, ships, automobiles, and even the equipment used to produce them. In addition, most uses of electricity depend on aluminum and copper.
Aside from ensuring the strength and durability of metals, metallurgy also plays a significant role in industrial technology industries, quality control, machine shop, welding, and materials science, all of which are involved in the process of designing, developing, and implementing metals and materials in the industry. With metallurgy involved throughout the entire process of producing metals, metallurgical engineers are able study the properties and behavior of metals, which enable them to offer their guidance, experience, and advice in order to come up with a better product.
Metallurgical Processes
Various metal compounds that exist in nature are mixed with impurities such as rock and sand (“Extraction of Metals,” 2010). Metallurgy consists of the different processes that are required to extract metals from their ores and to subsequently refine them.
The following diagram provides an overview of this process:
Figure 1 The process of extracting metal
There is no uniform process for extracting metal from its ore as this is dependent on the nature of the metal and the ore (“Metallurgical Processes,” 2010). However, some common steps are involved in all metallurgical processes and this section describes those steps.
1. Mine the ore.
“Mining is the process of taking out the ores from the mines” (“Metallurgical Processes”). Open-pit mining is performed when the ore is located near the earth’s surface, and deep-mining is performed when the ore is located more deeply.
2. Crush the ore.
With the ore coming in the form of big lumps, it must be broken into smaller pieces through the use of a jaw-crusher or through hammering in a hammer mill.
3. Grind and pulverize the crushed ore.
The crushed ore must be pulverized into fine powder using a pulveriser or a stamp mill.
4. Remove impurities from the ore.
If the impurities in the ore are large enough and are distinct from the ore then they can be removed through hand picking. This is a slow method, which is usually performed at the early stages of concentration. However, more sophisticated processes for the removal of impurities are employed if the impurities are too tiny. Some of these processes would include the levigation or gravity method; magnetic separation; the froth flotation process; and the leaching process.
5. Convert the ore into oxide.
The process of calcination or roasting can be performed to convert the concentrated ore into oxide. With calcination, the concentrated ore is strongly heated in the absence of air. With roasting, concentrated ore is strongly heated in the presence of air. These help in the removal of moisture and volatile impurities from the ore.
References
Extraction of Metals – Metallurgy. (2010). Retrieved from
http://www.tutorvista.com/content/science/science-ii/metals-non-metals/extraction-
metallurgy.php
This article provides a brief description of metallurgy in terms of the processes involved
in the extraction of metals from their ores. This article also provides a diagram that
depicts each stage of the metallurgical process.
Metallurgical Processes. (2010). Retrieved from http://chemistry.tutorvista.com/inorganic-
chemistry/metallurgy.html
This article provides descriptions of the common steps involved in the process of
extracting metal from ore. These steps include the mining of the ore; crushing of the ore;
grinding and pulverization of the crushed ore; concentration of the ore; hand picking;
levigation method; magnetic separation; froth flotation process; leaching process;
calcination; and roasting.
Metallurgy. (2011, October 27). Retrieved from http://www.mahalo.com/metallurgy/
This article provides a brief description and the importance of metallurgy as a field of
science. It also provides a description of metals and alloys and includes a video that
demonstrates the process of prehistoric iron smelting.
Tom Bertone Consulting. (2012). What is metallurgy?. Retrieved from
http://www.metallurgy.com/about/metallurgy.cfm
This article provides an overview of the science of metallurgy by providing a definition, a brief historical background, and its relevance, particularly the role that it plays in our everyday life.
WiseGeek. (n.d.). What is Metallurgy?. Retrieved from http://www.wisegeek.com/what-is-
metallurgy.htm
This article provides a description and a brief history of metallurgy. It also briefly
discusses the two subtypes of modern metallurgy as well as the type of work that
metallurgical engineers are involved in.
