
Smelting Gold in Nicaragua in the La Luz Gold Mine in Siuna and Bonanza about 1959.
Smelting is a basic step in obtaining usable quantities of most metals.
Pouring Smelted Gold into an ingot at the La Luz Gold Mine in Siuna, Nicaragua about 1959.



Etymology and pronunciation





Gold headband from Thebes 750–700 BC

The earliest recorded metal employed by humans appears to be gold, which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC.[3] Silver, copper, tin and meteoric iron can also be found in native form, allowing a limited amount of metalworking in early cultures.[4] Egyptian weapons made from meteoric iron in about 3000 BC were highly prized as "daggers from heaven".[5]

Certain metals, notably tin, lead and (at a higher temperature) copper, can be recovered from their ores by simply heating the rocks in a fire or blast furnace, a process known as smelting. The first evidence of this extractive metallurgy dates from the 5th and 6th millennia BC[6] and was found in the archaeological sites of Majdanpek, Yarmovac and Plocnik, all three in Serbia. To date, the earliest evidence of copper smelting is found at the Belovode site,[7] including a copper axe from 5500 BC belonging to the Vinča culture.[8] Other signs of early metals are found from the third millennium BC in places like Palmela (Portugal), Los Millares (Spain), and Stonehenge (United Kingdom). However, the ultimate beginnings cannot be clearly ascertained and new discoveries are both continuous and ongoing.







Furnace bellows operated by waterwheels, Yuan Dynasty, China.
Aluminium plant in Žiar nad Hronom (Central Slovakia)
Main article: Extractive metallurgy






Casting bronze

Common engineering metals include aluminium, chromium, copper, iron, magnesium, nickel, titanium and zinc. These are most often used as alloys. Much effort has been placed on understanding the iron-carbon alloy system, which includes steels and cast irons. Plain carbon steels (those that contain essentially only carbon as an alloying element) are used in low-cost, high-strength applications where weight and corrosion are not a problem. Cast irons, including ductile iron, are also part of the iron-carbon system.


Copper-nickel alloys (such as Monel) are used in highly corrosive environments and for non-magnetic applications. Nickel-based superalloys like Inconel are used in high-temperature applications such as gas turbines, turbochargers, pressure vessels, and heat exchangers. For extremely high temperatures, single crystal alloys are used to minimize creep.



Metalworking processes

Main article: Metalworking

Metals are shaped by processes such as:


Various forms of casting exist in industry and academia. These include sand casting, investment casting (also called the "lost wax process"), die casting, and continuous casting.

Heat treatment

Metals can be heat-treated to alter the properties of strength, ductility, toughness, hardness and/or resistance to corrosion. Common heat treatment processes include annealing, precipitation strengthening, quenching, and tempering.[13] The annealing process softens the metal by heating it and then allowing it to cool very slowly, which gets rid of stresses in the metal and makes the grain structure large and soft-edged so that when the metal is hit or stressed it dents or perhaps bends, rather than breaking; it is also easier to sand, grind, or cut annealed metal. Quenching is the process of cooling a high-carbon steel very quickly after heating, thus "freezing" the steel's molecules in the very hard martensite form, which makes the metal harder. There is a balance between hardness and toughness in any steel; the harder the steel, the less tough or impact-resistant it is, and the more impact-resistant it is, the less hard it is. Tempering relieves stresses in the metal that were caused by the hardening process; tempering makes the metal less hard while making it better able to sustain impacts without breaking.

Often, mechanical and thermal treatments are combined in what are known as thermo-mechanical treatments for better properties and more efficient processing of materials. These processes are common to high-alloy special steels, super alloys and titanium alloys.


Main article: Plating


Thermal spraying

Main article: Thermal spraying



Metallography allows the metallurgist to study the microstructure of metals.




EMC, the European Metallurgical Conference has developed to the most important networking business event dedicated to the non-ferrous metals industry in Europe. From the start of the conference sequence in 2001 at Friedrichshafen it was host of the most relevant metallurgists from all countries of the world. The European Metallurgical Conference is organized by GDMB Society of Metallurgists and Miners.

See also


  1. "Металлургия". in The Great Soviet Encyclopedia. 1979.
  2. Oxford English Dictionary, accessed 29 January 2011
  3. "History of Gold". Gold Digest. Retrieved 2007-02-04.
  4. E. Photos, E. (2010). "The Question of Meteoritic versus Smelted Nickel-Rich Iron: Archaeological Evidence and Experimental Results" (PDF). World Archaeology. 20 (3): 403. doi:10.1080/00438243.1989.9980081. JSTOR 124562.
  5. 1 2 W. Keller (1963) The Bible as History. p. 156. ISBN 0-340-00312-X
  6. H.I. Haiko, V.S. Biletskyi. First metals discovery and development the sacral component phenomenon. // Theoretical and Practical Solutions of Mineral Resources Mining // A Balkema Book, London, 2015, р. 227-233..
  7. Radivojević, Miljana; Rehren, Thilo; Pernicka, Ernst; Šljivar, Dušan; Brauns, Michael; Borić, Dušan (2010). "On the origins of extractive metallurgy: New evidence from Europe". Journal of Archaeological Science. 37 (11): 2775. doi:10.1016/j.jas.2010.06.012.
  8. Neolithic Vinca was a metallurgical culture Stonepages from news sources November 2007
  10. R. F. Tylecote (1992) A History of Metallurgy ISBN 0-901462-88-8
  12. Karl Alfred von Zittel (1901). History of Geology and Palaeontology. p. 15. doi:10.5962/bhl.title.33301.
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Wikisource has the text of the 1879 American Cyclopædia article Metallurgy.