Editing Bitumen (section)

{{short description|Form of petroleum primarily used in road construction}}
{{Use dmy dates|date=July 2020}}
[[File:Bitumen.jpg|300px|thumb|Natural bitumen from the [[Dead Sea]] ]]
[[File:Refined bitumen.JPG|thumb|Refined bitumen]]
[[File:University of Queensland Pitch drop experiment-white bg.jpg|thumb|upright|The University of Queensland [[pitch drop experiment]], demonstrating the [[viscosity]] of bitumen]]

'''Bitumen''' ({{IPAc-en|uk|ˈ|b|ɪ|tʃ|ʊ|m|ɪ|n}} {{respell|BIH|chuum|in}}, {{IPAc-en|us|b|ɪ|ˈ|tj|uː|m|ɪ|n|,_|b|aɪ|-|audio=LL-Q1860 (eng)-Naomi Persephone Amethyst (NaomiAmethyst)-bitumen.wav}} {{respell|bih|TEW|min|,_|by|-}})<ref>{{cite EPD|18}}</ref> is an immensely [[viscosity|viscous]] constituent of [[petroleum]]. Depending on its exact composition, it can be a sticky, black liquid or an apparently solid mass that behaves as a liquid over very large time scales. In [[American English]], the material is commonly referred to as '''asphalt''' or '''tar'''. Whether found in natural deposits or refined from petroleum, the substance is classed as a [[pitch (resin)|pitch]].<ref>{{cite web |title=CPC Definition – C10C Working-up Pitch, Asphalt, Bitumen, Tar; Pyroligneous Acid |url=https://uspto.gov/web/patents/classification/cpc/html/defC10C.html |access-date=12 August 2023 |website=Classification Resources |publisher=[[United States Patent and Trademark Office]] |date=November 2016}}</ref> Prior to the 20th century, the term '''asphaltum''' was in general use.<ref name="Abraham1938">{{cite book |first=Herbert|last=Abraham |year=1938 | title=Asphalts and Allied Substances: Their Occurrence, Modes of Production, Uses in the Arts, and Methods of Testing |edition=4th |publisher=D. Van Nostrand Co., Inc. |location=New York |url=https://archive.org/details/asphaltsandallie031010mbp}}</ref> The word derives from the [[Ancient Greek]] word {{Wikt-lang|grc|ἄσφαλτος}} ({{grc-transl|ἄσφαλτος}}), which referred to natural bitumen or pitch. The largest natural deposit of bitumen in the world is the [[Pitch Lake]] of southwest [[Trinidad]], which is estimated to contain 10 million tons.<ref>{{cite web |title=The unique pitch lakes of the world |first=Oishimaya Sen|last=Nag |work=World Atlas |date=17 February 2021 |access-date=12 March 2021 |url= https://worldatlas.com/articles/the-five-natural-asphalt-lake-areas-in-the-world.html}}</ref>

About 70% of annual bitumen production is destined for [[road surface|road construction]], its primary use.<ref>{{cite web |title=Asphalt Applications |url=https://mineralproducts.org/Mineral-Products/Asphalt/Asphalt-Applications.aspx#:~:text=The%20main%20use%20of%20asphalts,a%20number%20of%20farming%20applications. |access-date=22 January 2022 |website=mineralproducts.org}}</ref> In this application, bitumen is used to bind [[construction aggregate|aggregate]] particles like gravel and forms a substance referred to as [[asphalt concrete]], which is colloquially termed ''asphalt''. Its other main uses lie in [[bituminous waterproofing]] products, such as [[roofing felt]] and roof sealant.<ref name="UllmannAsph">{{Ullmann |doi=10.1002/14356007.a03_169.pub2 |title=Asphalt and Bitumen |year=2009 |last1=Sörensen|first1=Anja |last2=Wichert|first2=Bodo |isbn=978-3-527-30673-2}}</ref>

In [[material science]]s and [[engineering]], the terms ''asphalt'' and ''bitumen'' are often used interchangeably and refer both to natural and manufactured forms of the substance, although there is regional variation as to which term is most common. Worldwide, geologists tend to favor the term ''bitumen'' for the naturally occurring material. For the manufactured material, which is a refined residue from the [[distillation]] process of selected crude oils, ''bitumen'' is the prevalent term in much of the world; however, in [[American English]], ''asphalt'' is more commonly used. To help avoid confusion, the terms "liquid asphalt", "asphalt binder", or "asphalt cement" are used in the U.S. to distinguish it from asphalt concrete. Colloquially, various forms of bitumen are sometimes referred to as "[[tar]]", as in the name of the [[La Brea Tar Pits]].<ref>{{cite book |last1=Brown|first1=E. R. |last2=Kandhal|first2=P. S. |last3=Roberts|first3=F. L. |last4=Kim|first4=Y. R. |last5=Lee|first5=D.-Y. |last6=Kennedy|first6=T. W. |title=Hot Mix Asphalt Materials, Mixture Design, and Construction |edition=Third |year=1991 |publisher=NAPA Education and Research Foundation |location=[[Lanham, Maryland]] |isbn=978-0-914313-02-1}}</ref>

Naturally occurring bitumen is sometimes specified by the term ''crude bitumen''. Its viscosity is similar to that of cold [[molasses]]<ref>{{cite web |title=Oil Sands Glossary |work=Oil Sands Royalty Guidelines |publisher=Government of Alberta |year=2008 |url=http://www.energy.gov.ab.ca/OilSands/1106.asp |archive-url=https://web.archive.org/web/20071101112113/http://www.energy.gov.ab.ca/OilSands/1106.asp |archive-date=1 November 2007 }}</ref><ref>{{Citation|last=Walker |first=Ian C. |title=Marketing Challenges for Canadian Bitumen |location=Tulsa, OK |publisher=International Centre for Heavy Hydrocarbons |year=1998 |url=http://www.oildrop.org/Info/Centre/Lib/7thConf/19980101.pdf |archive-url=https://web.archive.org/web/20120313084908/http://www.oildrop.org/Info/Centre/Lib/7thConf/19980101.pdf |archive-date=13 March 2012 |url-status=usurped |quote=Bitumen has been defined by various sources as crude oil with a dynamic viscosity at reservoir conditions of more than 10,000 centipoise. Canadian "bitumen" supply is more loosely accepted as production from the Athabasca, Wabasca, Peace River and Cold Lake oil-sands deposits. The majority of the oil produced from these deposits has an API gravity of between 8° and 12° and a reservoir viscosity of over 10,000 centipoise although small volumes have higher API gravities and lower viscosities. }}</ref> while the material obtained from the [[fractional distillation]] of [[crude oil]] boiling at {{convert|525|C|F}} is sometimes referred to as "refined bitumen". The Canadian province of [[Alberta]] has most of the world's reserves of natural bitumen in the [[Athabasca oil sands]], which cover {{convert|142000|km2}}, an area larger than [[England]].<ref name="ST98">{{cite web| title = ST98-2015: Alberta's Energy Reserves 2014 and Supply/Demand Outlook 2015–2024| work = Statistical Reports (ST)| publisher = Alberta Energy Regulator| year = 2015| url = http://www.aer.ca/documents/sts/ST98/ST98-2015.pdf| access-date = 19 January 2016| archive-url = https://web.archive.org/web/20190430135147/https://aer.ca/documents/sts/ST98/ST98-2015.pdf| archive-date = 30 April 2019}}</ref>