Crucible
A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. Although crucibles have historically tended to be made out of clay,[1] they can be made from any material that withstands temperatures high enough to melt or otherwise alter its contents.
History
Typology and chronology
The form of the crucible has varied through time, with designs reflecting the process for which they are used, as well as regional variation. The earliest crucible forms derive from the sixth/fifth millennium B.C. in Eastern Europe and Iran.[2]
Chalcolithic
Crucibles used for
A crucible furnace dating to 2300–1900 BC for
Iron Age
The use of crucibles in the Iron Age remains very similar to that of the Bronze Age with copper and tin smelting being used to produce bronze. The Iron Age crucible designs remain the same as the Bronze Age.[citation needed]
The Roman period shows technical innovations, with crucibles for new methods used to produce new alloys. The smelting and melting process also changed with both the heating technique and the crucible design. The crucible changed into rounded or pointed bottom vessels with a more conical shape; these were heated from below, unlike prehistoric types which were irregular in shape and were heated from above. These designs gave greater stability within the charcoal.[8] These crucibles in some cases have thinner walls and have more refractory properties.[9]
During the Roman period a new process of metalworking started,
Medieval period
Smelting and melting of copper and its
The cementation process, which was lost from the end of the Roman to the early Medieval period, continued in the same way with brass. Brass production increased during the medieval period due to a better understanding of the technology behind it. Furthermore, the process for carrying out cementation for brass did not change greatly until the 19th century.[15]
However, during this period a vast and highly important technological innovation happened using the cementation process, the production of crucible steel. Steel production using iron and carbon works similarly to brass, with the iron metal being mixed with carbon to produce steel. The first examples of cementation steel are wootz steel from India,[16] where the crucibles were filled with good quality low-carbon wrought iron and carbon in the form of organics such as leaves, wood, etc. However, no charcoal was used within the crucible. These early crucibles would only produce a small amount of steel as they would have to be broken once the process has finished.
By the late Medieval period, steel production had moved from India to modern-day Uzbekistan where new materials were being used in the production of steel crucibles, for example, Mullite crucibles were introduced.[17] These were sandy clay crucibles which had been formed around a fabric tube.[17] These crucibles were used in the same way as other cementation vessels but with a hole in the top of the vessel to allow pressure to escape.
Post-Medieval
At the end of the
The refining of methods during the Medieval and Post-Medieval periods led to the invention of the cupel which resembles a small egg cup, made of ceramic or bone ash which was used to separate base metals from noble metals. This process is known as cupellation. Cupellation started long before the Post Medieval period, however, the first vessels made to carry out this process started in the 16th Century.[19] Another vessel used for the same process is a scorifier which is similar to a cupel but slightly larger and removes the lead and leaves the noble metals behind. Cupels and scorifiers were mass-produced as after each reduction the vessels would have absorbed all of the lead and become fully saturated. These vessels were also used in the process of metallurgical assay where the noble metals are removed from a coin or a weight of metal to determine the amount of the noble metals within the object.
Modern-day uses
Crucible is used in the
Crucibles and their covers are made of high temperature-resistant materials, usually
In the area of chemical analysis, crucibles are used in quantitative gravimetric chemical analysis (analysis by measuring
A crucible with a bottom perforated with small holes which are designed specifically for use in filtration, especially for gravimetric analysis as just described, is called a Gooch crucible after its inventor, Frank Austin Gooch.
For completely accurate results, the crucible is handled with clean
See also
References
- ^ Percy, John. Natural Refractory Materials Employed in the Construction of Crucibles, Retorts, Forunaces &c. Metallurgy. London: W. Clowes and Sons, 1861. 208–09. Print.
- ^ Pigott, Vincent C. "The Neolithic (C.A 7500–5500 B.C) and Caltholithic (C.A 5500–3200 B.C) Periods." The Archaeometallurgy of the Asian Old World. Philadelphia: UPenn Museum of Archaeology, 1999. 73–74. Google Scholar. Web.
- ^ Rehren T. & Thornton C. P, 2009, A truly refractory crucible from fourth millennium Tepe Hissar, Northeast Iran, Journal of Archaeological Science, Vol. 36, pp2700–2712
- ^ a b Hauptmann A., 2003, Developments in copper Metallurgy During the Fourth and Third Millennia B.C. at Feinan, Jordan, P. Craddock & J. Lang, Eds, Mining and Metal Production Through the Ages, British Museum Press, London, pp93–100
- ^ Bayley & Rehren 2007: p 47
- ^ a b Rehren Th., 2003, Crucibles as Reaction Vessels in Ancient Metallurgy, Ed in P. Craddock & J. Lang, Mining and Metal Production Through the Ages, British Museum Press, London pp207–215
- JSTOR 2155851.
- ^ Bayley & Rehren 2007: p 49
- ^ Tylecote 1976: p 20
- ^ Zwicker et al. 1985: p 107
- ^ Rehren 2003: p 209
- ^ Rehren 1999: p 1085
- ^ Rehren Th., 1999, Small Size, Large Scale Roman brass Production in Germania Inferior, Journal of Archaeological Science, Vol. 26, pp 1083–1087
- ^ Tylecote 1976: p 73
- ^ Craddock P., 1995, Early Metal Mining and Production, Edinburgh University Press Ltd, Edinburgh
- ^ Craddock 1995: p 276
- ^ a b Rehren, Th. and Papakhristu, O., 2000, Cutting Edge Technology – The Ferghana Process of Medieval crucible steel Smelting, Metalla, Bochum, 7(2) pp55–69
- ^ Martinon-Torres M. & Rehren Th., 2009, Post-Medieval crucible Production and Distribution: A Study of Materials and Materialities, Archaeometry Vol.51 No.1 pp49–74
- ^ Rehren 2003: p 208
- ^ https://www.scienceequip.com.au/blogs/news/what-are-lab-crucibles-used-for
Bibliography
- Craddock P., 1995, Early Metal Mining and Production, Edinburgh University Press Ltd, Edinburgh
- Hauptmann A., T. Rehren & Schmitt-Strecker S., 2003, Early Bronze Age copper metallurgy at Shahr-i Sokhta (Iran), reconsidered, T. Stollner, G. Korlin, G. Steffens & J. Cierny, Eds., Man and mining, studies in honour of Gerd Weisgerber on occasion of his 65th birthday, Deutsches Bergbau Museum, Bochum
- Martinon-Torres M. & Rehren Th., 2009, Post Medieval crucible Production and Distribution: A Study of Materials and Materialities, Archaeometry Vol.51 No.1 pp49–74
- O. Faolain S., 2004, Bronze Artefact Production in Late Bronze Age Ireland: A Survey, British Archaeological Report, British Series 382, Archaeopress, Oxford
- Rehren, Th. and Papakhristu, O., 2000, Cutting Edge Technology – The Ferghana Process of Medieval crucible steel Smelting, Metalla, Bochum, 7(2) pp55–69
- Rehren T. & Thornton C. P, 2009, A truly refractory crucible from fourth millennium Tepe Hissar, Northeast Iran, Journal of Archaeological Science, Vol. 36, pp2700–2712
- Rehren Th., 1999, Small Size, Large Scale Roman brass Production in Germania Inferior, Journal of Archaeological Science, Vol. 26, pp 1083–1087
- Rehren Th., 2003, Crucibles as Reaction Vessels in Ancient Metallurgy, Ed in P. Craddock & J. Lang, Mining and Metal Production Through the Ages, British Museum Press, London pp207–215
- Roberts B. W., Thornton C. P. & Pigott V. C., 2009, Development of Metallurgy in Eurasia, Antiquity Vol. 83 pp 1012–1022
- Scheel B., 1989, Egyptian Metalworking and Tools, Shire Egyptology, Bucks
- Vavelidis M. & Andreou S., 2003, Gold and Gold working in Later Bronze Age Northern Greece, Naturwissenschaften, Vol. 95, pp 361–366
- Zwicker U., Greiner H., Hofmann K. & Reithinger M., 1985, Smelting, Refining and Alloying of copper and copper Alloys in Crucible Furnaces During Prehistoric up to Roman Times, P. Craddock & M. Hughes, Furnaces and Smelting Technology in Antiquity, British Museum, London