Examine individual changes

'{{For|the Austrian municipality|Droß}} [[File:Aluminium dross2.png|Aluminium dross|right|thumb]]dicks overpowered '''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 such as steel, oxidized impurities melt and float making them easy to pour off. With [[wrought iron]], hammering and later [[Rolling (metalworking)|rolling]] removed 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 |coauthors= |year=1969|publisher=Press Syndicate of the University of Cambridge |location=Cambridge, New York |isbn= 0-521-09418-6|pages=91 |postscript= <!--None--> }}</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 used in secondary [[steelmaking]] for slag [[deoxidizer|deoxidation]].<ref>{{Citation | last = Kogel | first = 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 = http://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. 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=http://books.google.co.uk/books?id=kf8n2v9ZjxIC|title=Chambers's Etymological Dictionary of the English Language|year=1875|publisher=W & R Chambers|pages=142}}</ref> The most popular usage of the word is now as an adjective for poorly written or even plagiarized journalism. ==See also== *[[Aluminium alloy inclusions]] *[[Slag]] ==Notes== {{reflist|group=note}} ==References== {{Reflist}} ==External links== {{Wiktionary}} *[http://www.azom.com/details.asp?ArticleID=2150 AZoM.com – Aluminium Dross Recycling] * Herbert F. Lund. [http://books.google.com/books?id=gIn8o0b6zj0C&pg=PT975&dq=aluminium+dross++recycling&ei=fR_zSu6MDYSOygTCxPSmDw&client=firefox-a#v=onepage&q=&f=false The McGraw-Hill recycling handbook]. Chapter 37.23: [[United Kingdom]]: [[European Union]] Directive Precipitates [[Aluminum]] "Dross" [[Recycling]]. * [http://www.smartwaste.co.uk/filelibrary/Cement_aluminium_dross.pdf Residues from aluminium dross recycling in cement] * [http://www.pyrogenesis.com/pdfs/pyro_drosite.pdf DrosRite Aluminum Recycling Process] {{Metalworking navbox|castopen}} [[Category:Casting (manufacturing)]] [[Category:Metallurgy]] [[Category:Deoxidizers]]'