Dross

2025-07-20T10:18:50Z

2A00:23C5:FE1C:3701:69DF:AE1C:B35A:1BDE: /* Etymology and usage */ "dross" is not an adjective: zero Google Books hits for "a dross article"; Wiktionary lists no adjective either

{{short description|Impurities in molten metal}}
{{for-multi|the Austrian municipality|Droß|the Venezuelan YouTuber|Dross (YouTuber)}}
[[File:Aluminium dross2.png|Aluminium dross|right|thumb]]
'''Dross''' is a [[mass]] of [[solid]] [[impurity|impurities]] floating on a [[molten metal]] or dispersed in the metal, such as in wrought iron. It forms on the surface of low-[[melting-point]] metals such as [[tin]], [[lead]], [[zinc]] or [[aluminium]] or [[alloy]]s by [[oxidation]] of the metal. For higher melting point metals and alloys such as [[steel]] and [[silver]], oxidized impurities melt and float making them easy to pour off.

With [[wrought iron]], hammering and later [[Rolling (metalworking)|rolling]] remove some dross.<ref>{{cite book
|title=The Unbound Prometheus: Technological Change and Industrial Development in Western Europe from 1750 to the Present
|last=Landes
|first=David S.
|authorlink=David Landes
|year=1969|publisher=Press Syndicate of the University of Cambridge
|location=Cambridge, New York
|isbn= 0-521-09418-6|pages=91
}}</ref>
With tin and lead the dross can be removed by adding [[sodium hydroxide]] pellets, which dissolve the oxides and form a [[slag]]. If floating, dross can also be skimmed off.

Dross, as a solid, is distinguished from [[slag]], which is a liquid. Dross product is not entirely waste material; for example, [[aluminium dross recycling|aluminium dross can be recycled]] and is also used in secondary [[steelmaking]] for slag [[deoxidizer|deoxidation]].<ref>{{Citation | last1 = Kogel | first1 = Jessica Elzea | last2 = Society for Mining, Metallurgy, and Exploration | title = Industrial minerals & rocks: commodities, markets, and uses | page = 1406 | publisher = SME | year = 2006 | edition = 7th | url = https://books.google.com/books?id=zNicdkuulE4C&pg=PA1406 | isbn = 978-0-87335-233-8 | postscript =.}}</ref>

==Etymology and usage==
The term ''dross'' derives from the [[Old English]] word ''dros'', meaning the scum produced when smelting metals (extracting them from their ores). By the 15th century it had come to refer to rubbish in general.<ref name="dr">{{cite web|title=Dross|url=http://www.etymonline.com/index.php?term=dross|work=www.etymologyonline.com}}</ref> ''Dregs'',<ref name="dr"/> and the geological term [[Druse (geology)|''druse'']] are also thought to be etymologically related.<ref>{{cite book|url=https://books.google.com/books?id=kf8n2v9ZjxIC|title=Chambers's Etymological Dictionary of the English Language|year=1875|publisher=W & R Chambers|pages=142|isbn=9781402168093}}</ref> Popular non-[[metalworking]] uses of the word are derogatory:
*poorly written or plagiarized journalism - "that article is utter dross", a stronger term than ''[[wikt:filler|filler]]''
*undesirable, unprofitable work - "let's home in on the [[lion's share]] and outsource the dross"; synonyms: [[corvée]] and [[drudgery]] which are growing [[archaism]]s in business<ref>[[wikt:dross|"dross"]] ''en.wiktionary.org''</ref> (noun); as strong a term as ''[[wikt:dogsbody|dogsbody]] work''

==See also==
*[[Aluminium alloy inclusions]]
*[[Slag]]

==References==
{{Reflist}}

==External links==
{{Wiktionary}}
*[https://www.azom.com/article.aspx?ArticleID=2150 AZoM.com – Aluminium Dross Recycling]
* Herbert F. Lund. [https://books.google.com/books?id=gIn8o0b6zj0C&dq=aluminium+dross++recycling&pg=PT975 The McGraw-Hill recycling handbook]. Chapter 37.23: [[United Kingdom]]: [[European Union]] Directive Precipitates [[Aluminum]] "Dross" [[Recycling]].

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[[Category:Deoxidizers]]
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Dross