[1] - قیر. )معرب ،
اِ) جسم جامد غیرمتبلور سیاه رنگی که سطح شکستگی آن مانندشیشه ناصاف است و در
اماکن نفتی قدیمی یافت میشود. ترکیب قیر همان ترکیبات هیدروکربورهای نفت است که
درنتیجه ٔ اکسیداسیون حالت جمود پیدا کرده است . قیرهای طبیعی که به نام مومیایی و
زفت رومی نیز نامیده میشوند و وزن مخصوص آنها بین 1/1 و 1/2 و سختی آنها کم و تقریباً 2 میباشد، علاوه بر ترکیبات هیدروکربور در
ترکیب آنها ازت و اکسیژن و حتی گوگرد هم وجود دارد. در طبیعت ممکن است قیرهای
معدنی با سنگهای آهکی آمیخته یا آنها را آغشته کرده باشد و در این صورت به نام
آسفالت طبیعی نامیده میشوند. ساختن آسفالت مصنوعی هم با استفاده از همین آسفالتهای
طبیعی صورت میگرفته .در پالایشگاههای نفت در ته دیگهای تصفیه مقادیر زیادی
هیدروکربورهای خمیری یا جامد باقی میماند و آن همان قیرهای مصنوعی است که به بازار
عرضه میشود و همه ٔ خواص قیرهای طبیعی را دارد. در بناها جهت جلوگیری ازنفوذ رطوبت
قیر را به کار میبرند. قیر در حدود 100 درجه حرارت ذوب میشود. زفت رومی . مومیایی .
قیر طبیعی . حجر قیر. اشبنت . قطران نفت . (فرهنگ فارسی معین).
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قار. (ع اِ) قیر. (برهان )
(قاموس ). قیر که بر کشتی و جز آن مالند. (آنندراج ). زفت . زفت رومی .
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قیر. قار است و بپارسی قیل گویند ابن مؤلف گوید نفط سیاه
چشمه آنست که این نفط را می‌پزند منجمد میشود پس در آب اندازند تا می‌بندد و قیل میشود
و در خوزستان این عمل می‌کنند و باطراف میبرند.
اختیارات بدیعی، ص:
363
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MUMY
نام های دیگر : مومیایی، شیره
کوه، قیر طبیعی، زفت
رومی ، قیر معدنی،عرق الجبال ، زفت البحر ،کفر الیهود ، فقر الیهود و آسفالت معدنی
و مومیا
سالهاست که بشر
با بررسی طبیعت اطراف خود و همچنین روش های درمانی که در گذشته های دور نیز در
طبیعت وجود داشته و حال نیز سعی در کشف این حقایق دارد این بار قصد معرفی ماده ای
که در طبیعت مورد استفاده درمانی بسیاری از ساکنین طبیعت قرار داشته را داریم .این
ماده که مورد توجه بسیاری از اطبای سنتی ایران زمین مانند ابن سینا نیز بوده ماده
ای است به رنگ قهوه ای متمایل به سیاه که در شکافها و شکستگی هایی که در مجاورت
ذخایر نفتی زیر زمینی در ارتفاعات کوه ها به صورت خود جوش یافت می شود. در طبیعت
حیواناتی که دچار جراحاتی شده و یا می شوند با ماساژ قسمت مجروح به مومنایی جوشیده
از دل کوه و همچنین با خوردن آن به درمان هر چه سریعتر خود می پردازند این ماده
معجزه گر بیشتر در ارتفاعات کوه های استان کرمان ، فارس و بندرعباس بیشتر دیده شده
است .
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قیر ماده‌ای است سیاه رنگ و خمیری شکل که
در عایقکاری رطوبت و ساخت آسفالت کاربرد
دارد. قیر انواع گوناگونی دارد که هر یک از انواع آن، دارای کاربرد خاصی است. قیر
از مشتقات نفت است و اغلب در پالایشگاه
نفت تولید میشود.
محتویات
قیر ماده‌ای هیدروکربنی است به
رنگ سیاه تا قهوه‌ای تیره که در سولفید کربن و تتراکلرید کربن[۱] کاملاً
حل میشود. قیر در دمای محیط، جامد است. اما
با افزایش دما، به حالت خمیری درمی‌آید و پس از آن مایع میشود.
کاربرد مهم قیر به علت وجود دو خاصیت مهم این ماده است؛
انواع قیر[ویرایش]
قیر استخراج شده از نفت یا سنگهای معدنی مخصوص،
قیر خالص نام دارد که با توجه به منشاء تشکیل، طبقه‌بندی میشود. قیرهای خالص
همچنین برای اینکه خواص مورد نظر برای کاربردهای مختلف را پیدا کنند، تحت
فرایندهای دیگر قرار می‌گیرند و انواع مختلف قیر را (ازجمله قیر دمیده، قیر محلول،
قیر امولسیون، قیر پلیمری و...) را تشکیل می‌دهند.
قیر نفتی و قیر طبیعی[ویرایش]
قیر معمولاً از تقطیر نفت خام به دست
می‌آید. چنین قیری قیر نفتی یا قیر تقطیری نامیده میشود.[۳] قیر نفتی
محصول دو مرحله تقطیر نفت خام در برج تقطیر است. در
مرحله نخست تقطیر، مواد سبک مانند بنزین و پروپان از نفت
خام جدا میشوند. این فرایند در فشاری نزدیک به یک اتمسفر
(واحد) انجام میشود. در مرحله دوم نیز ترکیبات سنگین مانند گازوئیل و نفت سفید خارج میشوند.
این فرایند در فشاری نزدیک به خلاء صورت می‌پذیرد. در نهایت مخلوطی از ذرات جامد
بسیار ریز به نام آسفالتن باقی میماند که
در ماده سیال گریس‌مانندی به نام مالتن غوطه‌ور است.[۴]
اما برخی از انواع قیر در طبیعت و در اثر تبدیل
تدریجی نفت خام و تبخیر مواد فرار آن در اثر گذشت سال‌های بسیار زیاد به دست می‌آید.
چنین قیری، قیر
طبیعی نامیده
میشود[۳] و دوام آن بیشتر از قیرهای نفتی است.[۵] چنین
قیری ممکن است به‌صورت خالص در طبیعت وجود داشته باشد (قیر دریاچه‌ای) مانند دریاچه قیر بهبهان ایران و دریاچه قیر تیرینیداد آمریکا،[۶] یا از معادن استخراج شود (قیر معدنی).[۵] قیر
طبیعی با نام یواینتایت
(Uintaite) نیز شناخته میشود.[نیازمند منبع]
قیر دمیده[ویرایش]
قیر دمیده از دمیدن هوای داغ به قیر خالص در مرحله
آخر عمل تصفیه به دست می‌آید. در این فرایند، هوای داغ با دمای ۲۰۰ تا ۳۰۰ درجه
سانتی‌گراد توسط لوله‌های سوراخ‌دار به محفظه حاوی قیر دمیده میشود. در اثر انجام
این فرایند، اتم‌های هیدروژن موجود در مولکول‌های هیدروکربورهای
قیر، با اکسیژن هوا
ترکیب میشود و با تشکیل آب، عملبسپارش اتفاق می‌افتد.[۲] قیر
دمیده نسبت به قیر خالص دارای درجه نفوذ کمتری است، درجه
نرمی بیشتری دارد و حساسیت کم تری نسبت به تغییرات دما دارد. این نوع قیر بیشتر در
ساختن ورق‌های پوشش بام، باتری اتومبیل و اندودکاری مورد استفاده قرار می‌گیرد.[۲] علامت
اختصاری قیر دمیده
R میباشد.
مثلاً قیر۸۰/۲۵
R به معنای
قیر دمیده با درجه نرمی ۸۰ و درجه نفوذ ۲۵
میباشد.[۷]
قیر مخلوط یا محلول[ویرایش]
قیر مخلوط به مخلوطی از قیر و یک حلال مناسب (مثلاً نفت سفید
یا بنزین) گفته میشود. این قیر در درجه‌حرارت محیط مایع است و یا با حرارت کمی به
مایع تبدیل میشود. قیر مخلوط در انواع آسفالتهای پوششی و ماکادامی مورد
استفاده قرار می‌گیرد.[۸] سرعت
گیرش یا سفت شدن این نوع قیر بستگی به نوع محلول دارد. به‌طور مثال به دلیل سرعت
بالای تبخیر بنزین،
قیر حل شده در بنزین سریعتر سفت میشود. این قیر، اصطلاحاً قیر تندگیر (RC) نامیده میشود. همچنین قیرهایی که در نفت حل شده‌اند، قیر
کندگیر
(MC) نامیده
میشوند و به قیرهایی که در نفت گاز یا نفت کوره حل شوند، نفت دیرگیر (SC) گفته میشود.[۲] قیرهای
محلول بر اساس درجه گرانروی‌شان درجه‌بندی
میشوند.[۲]
قیر ترینیداد[ویرایش]
در ترینیداد، قیر را
از دهانهٔ آتشفشان خاموش در
می‌آورند. رویهٔ بستهٔ قیر را شکسته، و از زیر آن قیر را برداشت می‌نمایند که باز قیر، روان شده
و جای آنچه که برداشته شده را پر می‌کند. این قیر دارای ناخالصی (جسمهای معدنی و
ریشهٔ گیاهان) است. آن را در دمای ۱۶۰ درجه آب کرده
، و صاف می‌کنند که آن را قیر ترینیداد پالوده(Trinidad-epure) می‌نامند و دارای ۳۸٫۵٪ جسمهای معدنی، و ۵٪ جسمهای آلی نامحلول در CS2 و ۵۶٫۵٪ قیر که در سولفور کربن حل میشود.
جسمهای معدنی که آنها را خاکستر
آتشفشانی و خاک رس کلوییدی می‌پندارند،
به گونهٔ دانه‌های ریز در آن پخش اند که این ریزدانه‌ها، درجهٔ نرمی و چکیدن
آن را بالا برده‌اند. قیر ترینیداد پالوده را در روغن‌های معدنی حل کرده
یا با قیر نفتی درهم و به کار میبرند. این قیر دارای چگالی ۱٫۴، درجهٔ نفوذ ۱٫۴ تا ۴ (در گرمای
۲۵ درجه)، درجهٔ نرمی ۷۸ تا ۸۴ و درجهٔ شکستن ۱۳ تا ۱۴ است .[۹]
قیرابه[ویرایش]
قیرابه (قیر امولسیون) با مخلوط کردن قیر و آب و
یک ماده امولسیون‌ساز به‌دست
می‌آید. مقدار ماده امولسیون ساز بسیار کم و در حدود ۰٫۳ تا ۰٫۵ درصد وزن
قیر میباشد. مقدار آب مصرفی این نوع قیر در حدود ۳۰ تا ۵۰ درصد وزن قیر میباشد.[۱۰] ماده
امولسیون‌ساز معمولاً یک نمک قلیایی اسیدهای آلی یا نمک آمونیم است که باعث باردار
شدن ذرات قیر میشود. به این ترتیب ذرات قیر در اثر بار القایی یکدیگر را دفع می‌کنند
و به‌صورت کره‌هایی با قطر یک‌صدم تا یک‌هزارم میلی‌متر در آب شناور میشوند.[۲] استفاده
از این نوع قیر، باعث کاهش آلایندگی محیط زیست میشود و چون از نفت یا حلال‌های
قابل اشتعال استفاده نمی‌شود، خطر اشتعال در حین حمل و نقل قیر کاهش می‌یابد.[۱۱]از قیر
امولسیونی برای آسفالت سرد در محیط‌های مرطوب یا برای عایق کاری استفاده میشود که
در این صورت باید دوباره به آن آب اضافه کرد و محتوای آن را به حدود ۶۵ درصد رساند.[۱۲]
کاربرد[ویرایش]
قیر معمولاً در دو حوزه راهسازی و عایقکاری به کار می‌رود.
حدوداً ۹۰ درصد از قیر تولیدی، در حوزه راهسازی مورد استفاده قرار می‌گیرد و مصارف
عایقکاری، تنها ۱۰ درصد از مصرف قیر را به خود اختصاص می‌دهد.[۱۳]
عایق کاری: از قیر معمولاً برای عایق بندی بام‌ها و کف حمام‌ها استفاده میشود.
معمولاً به منظور تثبیت قیر، آن را همراه با گونی مورد استفاده قرار می‌دهند که به
آنقیرگونی گفته میشود.
الیاف گونی نقش مسلح کننده قیر را دارند و قیر را در محل خود تثبیت می‌کنند. هم
چنین محصولاتی مانند مقوای قیری یا
نمد قیری که با نام‌های تجاری نظیر ایزوگام و...
ارائه میشوند نیز کاریردی مشابه قیرگونی دارند.
به منظور جلوگیری از نفوذ رطوبت زمین به کف ساختمان، از بلوکاژ یا ماکادم استفاده
میشود.[۱۴]
مشخصات قیر[ویرایش]
۱-درجه نفوذ:
آزمایش
درجه نفوذ برای تعیین سختی قیر مورد استفاده قرار می‌گیرد. در این آزمایش از یک
سوزن استاندارد تحت اثر بار ۱۰۰ گرمی در مدت ۵ ثانیه به داخل قیر در دمای ۲۵ درجه
نفوذ می‌کند. مقدار نفوذ برحسب دهم میلی‌متر درجه نفوذ نامیده میشود. هر چه درجه
نفوذ کم تر باشد قیر سخت تر است.[۱۵]
۲-گرانروی:
هر چه
کند روانی قیر بیش تر باشد خواص جامد بیش تری از خود نشان می‌دهد. واضح است در
دماهای بالاتر کند روانی کم تر است. این مشخصه قیر با دستگاهسی بولت فیورل و یا به
روش کینماتیکی اندازه‌گیری میشود.[۱۶]
۳-درجه اشتعال: درجه
اشتعال دمایی است که اگر قیر به آن دما برسد، گازهای متصاعد از آن با نزدیک شدن
شعله، مشتعل میشوند و در سطح آن شعله به وجود می‌آید. حداکثر دمایی که می‌توان
قیر را در کارگاه گرم کرد به درجه اشتعال محدود میباشد.[۱۷]
۴-افت وزنی: افت وزنی قیر در دمای بالا، در اثر تبخیر
قسمتی از روغن‌ها و ترکیبات نفتی آن میباشد. این مشخصه نیز از خواص مهم قیر است.
افت وزنی قیر در اُوِن در دمای ۱۶۳ درجه سانتی گراد و در مدت ۵ ساعت
(شرایط تقریبی پخت آسفالت) اندازه‌گیری میشود.[۱۸]
۵-شکل پذیری یا انگمی: اگر نمونه‌ای از
قیر با سطح مقطع ۱ سانتی‌متر مربع را با سرعت ۵ سانتی‌متر/دقیقه بکشیم، مقدار
افزایش طول نمونه را قبل از پاره شدن خاصیت انکمی قیر گویند.[۱۹]
۶-درجه خلوص: می‌دانیم حلال قیر تترا کلرور کربن و سولفور کربن است.
بنابراین اگر نمونه‌ای از قیر را در هر یک از این مواد حل کنیم، ناخالصی‌های آن
باقی میماند و از آن جا درجهٔ خلوص قیر
را می‌توانیم تعیین کنیم. درجه خلوص عبارت است از: (وزن نمونه قیر) ÷ [(وزن ناخالصی)
- (وزن قیر)][۲۰]
۷-درجه نرمی: درجه نرمی دمایی است که با رسیدن قیر به
آن دما، قیر از حالت جامد به حالت روان در می‌آید. هرچه درجه نرمی قیر بیش تر
باشد، حساسیت کم تری نسبت به تغییرات دما دارد. درجه نرمی قیرهای معمولی حدود ۶۰
تا ۷۰ میباشد.[۲۱]
آزمایش‌های تعیین خصوصیات قیر[ویرایش]
ازمایشهای زیر خصوصیات قیر طبیعی را تعیین می‌کند:
4.
اندازه‌گیری نقطه
شکست
(Fraass Breaking Point)
5.
بررسی اثر حرارت
و هوا روی قیر
(Thin Film Over Test)
6.
اندازه‌گیری
گرانروی
(Viscosity-ASTM D88-ASTM D445)
10.
اندازه‌گیری
استقامت مخلوطهای آسفالتی به روش مارشال (Marshall)
11.
آنالیز غربالی
مصالح معدنی
(Sieve Analysis)
12.
استخراج و آزمایش
قیر در مخلوطهای آسفالتی
(Extraction)
13.
اانبار کردن قیر
و ازمایشهای جدید قیر
جستارهای وابسته[ویرایش]
منابع[ویرایش]
2.
↑ پرش به بالا به:۲٫۰ ۲٫۱ ۲٫۲ ۲٫۳ ۲٫۴ ۲٫۵ طباطبایی،
امیرمحمد. «فصل پنجم». در روسازی
راه.
چاپ
پنجم. مرکز نشر دانشگاهی، ۱۳۷۶. ۱۵۵.
3.
↑ پرش به بالا به:۳٫۰ ۳٫۱ حاج‌محمدرضایی،
عباس. راه و
آسفالت.
چاپ اول.
انتشارات آدنا، ۱۳۷۷. ۱۳۴. شابک ۹۶۴۹۱۶۹۲۰۲.
4.
پرش به بالا↑ «جاده‌های کشور به‌زودی رنگارنگ میشوند».
پایگاه
اینترنتی همشهری آنلاین.
بازبینی‌شده
در ۴ آذر ۱۳۸۶.
8.
پرش به بالا↑ ملک‌زاده، داود،
معماریان، محمدرضا. اصلاح و
بهبود خواص قیرها با استفاده از لاستیک قابل بازیافت. . دومین همایش قیر و آسفالت ایران، دانشگاه تهران، آذر
۱۳۸۳.
/////////////////
الزفت[1] أو الأسفلت[1] أو القير[1] أو الحُمًّر[2] مادة نفطية ذات لزوجة عالية وذات لون أسود، يستخرج من خلال عملية تقطير النفط الخام تحت الضغط ودرجات حرارة عالية تصل إلى 300 درجة مئوية. وله أنواع
عديدة تختلف فيما بينها بنسبة السيولة والتركيز وكذلك باختلاف درجة حرارة انصهارها
والتجمد.
تستخدم كمادة لاصقة بين
جزيئات حجارة البناء الصغيرة (الزلط) لتصبح معها وسيلة جيدة وفعالة لرصف الشوارع وأرض المطارات، ويستخدم لطلاء
أسطح المنازل لمنع تسرب المياه.
يتألف الأسفلت بشكل رئيسي من
مزيج مكثف من الهيدروكربونات
العطرية متعددة الحلقات. وينحل الأسفلت بالكامل في ثنائي كبريتيد الكربون CS2
مراجع[عدل]
طالع أيضا[عدل]
////////////////
به ترکی آذربایجانی (جمهوری) قیر :
)قیر) — کاربوهیدروژئنلردن و اونلارین اوکسیژنلی،
گوگوردلو، آزوتلو تؤرملریندن عیبارت قاترانا اوخشار طبیعی و یا
سونی مورکب عوضوو ماده‌لرین عمومی آدی.
ایکی
نؤعه بؤلونور – سونی و طبیعی. برک و اؤزلو نئفت قیرلاری یئر قابیغیندا قومداشی و
آهکداشی لایلارینا هوپاراق همچئنین چاتلاری دولدوراراق یاتاقلار عمله گتیریر. قیر
یاتاقلاری نفتلی، قازلی ساحه‌‌لرله علاقه‌داردیر. سونی (تئخنیکی قیر) اساساً،
ترکیبینده آسفالت–قاتران ماده‌لری چوخ اولان آغیر نفت قالیقلارینی (مازوت، قودرون
و س.) 300 – 350° C-ده یوکسک واکویومدا دیستیلله ائتمکله و نئفت اعمالی قالیقلارینی (قودرون و س.)
260 – 280° C-ده هوانین اوکسیژنی ایله اوکسیدلشدیرمکله آلینیر.
قیر
عادتن یول اینشیاتیندا، پلاستیک کوتله و س. حاضیرلانماسیندا ایشلدیلیر. صنایع‌ده
ایشلدیلن قیرین عمومی مقدارینین 90% سونی قیر نؤعلرینین پایینا دوشور.
//////////////
به
عبری:
אספלט (או בעברית: חֵמָר) הוא נוזל צמיג שמופיע באופן טבעי בנפט גולמי. ניתן להפריד את האספלט מהמרכיבים
האחרים בנפט גולמי (כמו נפט, בנזין וסולר) על ידי תהליך של זיקוק.
ניתן להשיג רמת הפרדה גבוהה
יותר על ידי עיבוד נוסף של המרכיבים הכבדים של הנפט הגולמי ביחידת דה-אספלטיזציה
שמשתמשת בפרופאן או בוטאן במצב סופר-קריטי כדי לפרק את המולקולות הארומטיות יותר, שאז מופרדות
מהשאר. ניתן לעבד את התוצר עוד יותר על ידי תגובה עם חמצן. הוא הופך אז לקשיח יותר (וצמיגי יותר).
לעתים
מבלבלים בין אספלט לזפת, שהוא חומר שנוצר על ידי זיקוק דסטרוקטיבי של
חומר אורגני. גם האספלט וגם הזפת מסווגים כביטומנים, סיווג שמכיל את כל החומרים
המסיסים בפחמן דו גופרתי.
כיוון
שאספלט מתקשה אם אינו נשמר בחימום, קשה להובילו בצורתו הגולמית ממקום למקום. לכן,
מערבבים אותו עם דיזל או קרוסין לפני המשלוח; ומפרידים את המרכיבים הללו,
הקלים מהאספלט, כאשר התערובת מגיעה ליעדה.
/////////////
به
کردی آسفالت، قیر:
Asfalt, qîr an jî hele xweyî çebuyî çimentoya asfaltê di
xwezayêda an jî beşa mezin ji prosesa rafîneya petrolê wek
berhemekî kêlekî tê destxistin. Avabuna kîmyevî a asfaltê, têkelangkî kompleks
ya hîdrokarbonan e. Di hindurê wîde
kêmzede ev element hene;
·
C
70-85 %
·
H 7-12 %
·
N 0-1 %
·
S 1-7 %
·
O 0-5 %
Rêje ya C/H , bandorekî mezin
li ser tevger u taybetmendiya asfaltê dike. Dema ev rêje kêmbu, giraniya
molekullî u viskozita wî jî kêm dibe. Avabuna asfaltê avabunekî kolloîdal e u
ji van endama pêk tê.
·
Asfaltînan-
Rêjeya C/H ji 0.8 tan mezin, reş, hişk, fireh, giraniya molekulêra bilind,
molekulên hîdrokarbonên vîskoz.
·
Rezînan-
Rêjeya C/H di navbera 0.4-0.8 tan de tê guherandin, giraniya molekulêra navîn u
molekulên hîdrokarbon ên navîn vîskoze.
·
Run- Rêjeya
C/H ji 0.4 an biçuk, giraniya molekulêra biçuk, herî reng vekirî u molekulên
hîdrokarbon ên herî hindik vîskoze.
به
اردو ایسفلت:
ایسفلت (Asphalt)
(تلفظ: امریکی
i/ˈæsfɔːlt/ یا برطانوی /ˈæsfælt/,[1][2] بعض اوقات /ˈæʃfɔːlt/), دیگر نامبائتومین(bitumen) (تلفظ: /bɪˈtjuːmən[unsupported input]baɪ-/),[3][4] پٹرولیم سے حاصل ہونے والا ایک چپچپا، سیاہ ور
انتہائی گاڑھا نیم ٹھوس مادہ ہے۔ ایسفلت کا بنیادی استعمال (70٪) سڑکوں کی تعمیر
میں ہے۔
////////////////
به
آذری بیتوم:
Bitum — karbohidrogenlərdən
və onların oksigenli, kükürdlü, azotlu törəmələrindən
ibarət qatrana oxşar təbii və ya süni mürəkkəb üzvü maddələrin ümumi adı.
İki növə bölünür – süni və təbii.
Bərk və özlü neft bitumları yer qabığında qumdaşı və əhəngdaşı laylarına
hoparaq həmçinin çatları dolduraraq yataqlar əmələ gətirir. Bitum
yataqları neftli, qazlı sahələrlə əlaqədardır.
Süni (texniki bitum) əsasən, tərkibində asfalt–qatran maddələri çox olan ağır
neft qalıqlarını (mazut, qudron və s.) 300 – 350° C-də yüksək vakuumda distillə
etməklə və neft emalı qalıqlarını (qudron və s.) 260 – 280° C-də havanın
oksigeni ilə oksidləşdirməklə alınır.
Bitum adətən yol inşaatında,
plastik kütlə və s. hazırlanmasında işlədilir. Sənayedə işlədilən bitumun ümumi
miqdarının 90%-i süni bitum növlərinin payına düşür.
////////////////
به
ترکی آسفالت:
Asfalt, dayanımlı akmaz halden katı
hale kadar değişkenlik gösteren siyah ve kahverengi organik bir maddedir.
/////////////////
Asphalt
From Wikipedia, the free
encyclopedia
"Bitumen" redirects here. For naturally
occurring bituminous sands used for petroleum production, see Oil sands.
For other uses, see Asphalt (disambiguation).
Note: The terms bitumen and asphalt are
mostly interchangeable, except where asphalt is used as an abbreviation for asphalt
concrete. This article uses "asphalt/bitumen" where either term
is acceptable.
Natural asphalt/bitumen from theDead Sea
refined asphalt/bitumen
The University of Queenslandpitch drop experiment, demonstrating the viscosity of
asphalt/bitumen
Asphalt (US
i/ˈæsfɔːlt/ or UK /ˈæsfælt/,[1][2] occasionally /ˈæʃfɔːlt/), also known as bitumen (US /bɪˈtjuːmən, baɪ-/,[3][4]UK /ˈbɪtjᵿmən/[5]) is a
sticky, black and highly viscous liquid or semi-solid form of petroleum.
It may be found in natural deposits or may be a refined product; it is a
substance classed as a pitch.
Until the 20th century, the termasphaltum was also used.[6] The
word is derived from the Ancient
Greek ἄσφαλτος ásphaltos.[7]
The primary use (70%) of asphalt/bitumen is in
road construction, where it is used as the glue or binder mixed withaggregate particles to create asphalt
concrete. Its other main uses are for bituminous waterproofing products,
including production of roofing
felt and for sealing flat roofs.[8]
The terms asphalt and bitumen are
often used interchangeably to mean both natural and manufactured forms of the
substance. In American English, asphalt (or asphalt cement) is
the carefully refined residue from the distillationprocess
of selected crude oils. Outside the United States, the product is often called
bitumen. Geologists often prefer the term bitumen. Common usage
often refers to various forms of asphalt/bitumen as "tar", such as at
the La Brea Tar Pits. Another archaic term for
asphalt/bitumen is "pitch".
Naturally occurring asphalt/bitumen is sometimes
specified by the term "crude bitumen". Its viscosity is similar to
that of cold molasses[9][10] while
the material obtained from the fractional distillation of crude oil boiling
at 525 °C (977 °F) is sometimes referred to as "refined
bitumen". The Canadian province of Alberta has
most of the world's reserves of natural bitumen, covering 142,000 square
kilometres (55,000 sq mi), an area larger than England.[11]
Contents
[hide]
·
3History
·
8Notes
Composition[edit]
See also: Asphaltene
The components of asphalt are classified into four
classes of compounds:
·
saturates, saturated hydrocarbons, the % saturates
correlates with softening point of the material
·
Naphthene aromatics, consisting of partially
hydrogenated polycyclic aromatic compounds.
·
Polar aromatics, consisting of high molecular
weight phenols and carboxylic
acids
·
Asphaltenes, consisting of high molecular weight
phenols and heterocyclic compounds
The naphthene aromatics and polar aromatics are
typically the majority components. Additionally, most natural bitumens contain organosulfur compounds, resulting in an
overall sulfur content of up to 4%. Nickel and vanadium are
found in the <10 as="" is="" level="" of="" petroleum.="" ppm="" some="" sup="" typical="">[8]
The substance is soluble in carbon
disulfide. It is commonly modelled as a colloid, with asphaltenes as
the dispersed phase and maltenes as the continuous phase.[12] and
"it is almost impossible to separate and identify all the different
molecules of asphalt, because the number of molecules with different chemical
structure is extremely large".[13]
Asphalt/bitumen can sometimes be confused with
"coal
tar", which is a visually similar black, thermoplastic material
produced by the destructive distillation of coal.
During the early and mid-20th century when town gas was
produced, coal tar was a readily available byproduct and extensively used as
the binder for road aggregates. The addition of tar to macadam roads
led to the word tarmac, which is now used in common parlance to refer to
road-making materials. However, since the 1970s, when natural gas succeeded town
gas, asphalt/bitumen has completely overtaken the use of coal tar in these
applications. Other examples of this confusion include the La
Brea Tar Pits and the Canadian oil sands,
both of which actually contain natural bitumen rather than tar. Pitch is
another term sometimes used at times to refer to asphalt/bitumen, as in Pitch Lake.
Occurrence[edit]
Bituminous outcrop of the Puy de la Poix, Clermont-Ferrand,
France
The great majority of asphalt used commercially is
obtained from petroleum. Nonetheless, large amounts of asphalt occur in
concentrated form in nature. Naturally occurring deposits of asphalt/bitumen
are formed from the remains of ancient, microscopic algae (diatoms) and other
once-living things. These remains were deposited in the mud on the bottom of
the ocean or lake where the organisms lived. Under the heat (above 50 °C)
and pressure of
burial deep in the earth, the remains were transformed into materials such as
asphalt/bitumen, kerogen, or petroleum.
Natural deposits of asphalt/bitumen include lakes
such as the Pitch Lake in Trinidad and Tobago and Lake
Bermudez in Venezuela. Natural seeps of
asphalt/bitumen occur in the La
Brea Tar Pits and in the Dead Sea.
Asphalt/bitumen also occurs in unconsolidated
sandstones known as "oil sands" in Alberta, Canada, and the similar
"tar sands" in Utah, US. The Canadian province of Alberta has
most of the world's reserves of natural bitumen, in three huge deposits
covering 142,000 square kilometres (55,000 sq mi), an area larger
than England or New
York state. These bituminous sands contain 166 billion barrels (26.4×109 m3)
of commercially established oil reserves, giving Canada the third largest oil
reserves in the world. and produce over 2.3 million barrels per day
(370×103 m3/d) of heavy
crude oil andsynthetic crude oil. Although historically it
was used without refining to pave roads, nearly all of the bitumen is now used
asraw
material for oil
refineries in Canada and the United States.[11]
The world's largest deposit of natural bitumen,
known as the Athabasca oil sands is located in the McMurray Formation of Northern Alberta.
This formation is from the early Cretaceous,
and is composed of numerous lenses of
oil-bearing sand with up to 20% oil.[14] Isotopic
studies attribute the oil deposits to be about 110 million years old.[15] Two
smaller but still very large formations occur in the Peace River oil sands and the Cold Lake oil sands, to the west and southeast
of the Athabasca oil sands, respectively. Of the Alberta bitumen deposits, only
parts of the Athabasca oil sands are shallow enough to be suitable for surface
mining. The other 80% has to be produced by oil wells using enhanced oil recovery techniques like steam-assisted gravity drainage.[16]
Much smaller heavy oil or bitumen deposits also
occur in the Uinta Basin in Utah, US. The Tar Sand Triangle deposit,
for example, is roughly 6% bitumen.[14]
Asphalt/bitumen occurs in hydrothermal
veins. An example of this is within the Uinta Basin of Utah, in the US,
where there is a swarm of laterally and vertically extensive veins composed of
a solid hydrocarbon termed Gilsonite.
These veins formed by the polymerization and solidification of hydrocarbons
that were mobilized from the deeper oil shales of the Green River Formation during burial and
diagenesis.[17]
Asphalt/bitumen is similar to the organic matter
in carbonaceous meteorites.[18] However,
detailed studies have shown these materials to be distinct.[19] The
vast Alberta bitumen resources are believed to have started out as living
material from marine plants and animals, mainly algae, that died millions of
years ago when an ancient ocean covered Alberta. They were covered by mud,
buried deeply over the eons, and gently cooked into oil by geothermal heat at a
temperature of 50 to 150 °C (120 to 300 °F). Due to pressure from the
rising of the Rocky Mountains in southwestern Alberta, 80 to
55 million years ago, the oil was driven northeast hundreds of kilometres into
underground sand deposits left behind by ancient river beds and ocean beaches,
thus forming the oil sands.[16]
History[edit]
Ancient times[edit]
The use of asphalt/bitumen for waterproofing and
as an adhesive dates at least to the fifth millennium BC
in the early Indus valley sites like Mehrgarh,
where it was used to line the baskets in which crops were gathered.[20]
In the ancient Middle East, the Sumerians used
natural asphalt/bitumen deposits for mortar between
bricks and stones, to cement parts of carvings, such as eyes, into place, for
ship caulking,
and for waterproofing.[6] The
Greek historian Herodotus said hot asphalt/bitumen was used as mortar
in the walls ofBabylon,[21] as
did Moses in
reference to the Tower of Babel.[22]
A 1 kilometre (0.62 mi) tunnel beneath the
river Euphrates at Babylon in
the time of Queen Semiramis (ca. 800 BC) was reportedly constructed of
burnt bricks covered with asphalt/bitumen as a waterproofing agent.[23]
Asphalt/bitumen was used by ancient
Egyptians to embalm mummies.[6][24] The Persian word
for asphalt is moom, which is related to the English wordmummy. The
Egyptians' primary source of asphalt/bitumen was the Dead Sea,
which the Romans knew as Palus Asphaltites (Asphalt
Lake).
Approximately 40 AD, Dioscorides described
the Dead Sea material as Judaicum bitumen, and noted other places
in the region where it could be found.[25]The
Sidon bitumen is thought to refer to asphalt/bitumen found at Hasbeya.[26] Pliny
refers also to asphalt/bitumen being found in Epirus.
It was a valuable strategic resource; the object of the first known battle for
a hydrocarbon deposit, between the Seleucids and
the Nabateans in
312 BC.[27]
In the ancient Far East, natural asphalt/bitumen
was slowly boiled to get rid of the higher fractions, leaving a thermoplastic material of
higher molecular weight which when layered on objects became quite hard upon
cooling. This was used to cover objects that needed waterproofing,[6] such
as scabbards and
other items. Statuettes of household deities were
also cast with this type of material in Japan, and probably also in China.
In North America, archaeological recovery has
indicated asphalt/bitumen was sometimes used to adhere stone projectile
points to wooden shafts.[28] In
Canada, aboriginal people used bitumen seeping out of the banks of the
Athabasca and other rivers to waterproof birch bark canoes, and also heated it
in smudge pots to ward off mosquitoes in the summer time.[16]
Early use in Europe[edit]
One hundred years after the fall of Constantinople in 1453, Pierre
Belon described in his work Observations in 1553 that pissasphalto,
a mixture of pitch and bitumen, was used in Dubrovnik for
tarring of ships from where it was exported to a market place in Venice where
it could be bought by anyone.[29] An
1838 edition of Mechanics Magazine cites an early use of
asphalt in France. A pamphlet dated 1621, by "a certain Monsieur
d'Eyrinys, states that he had discovered the existence (of asphaltum) in large
quantities in the vicinity of Neufchatel", and that he proposed to use it
in a variety of ways – "principally in the construction of air-proof
granaries, and in protecting, by means of the arches, the water-courses in the
city of Paris from the intrusion of dirt and filth", which at that time
made the water unusable. "He expatiates also on the excellence of this
material for forming level and durable terraces" in palaces, "the
notion of forming such terraces in the streets not one likely to cross the
brain of a Parisian of that generation".[30] But
it was generally neglected in France until the revolution
of 1830. Then, in the 1830s, there was a surge of interest, and asphalt
became widely used "for pavements, flat roofs, and the lining of cisterns,
and in England, some use of it had been made of it for similar purposes".
Its rise in Europe was "a sudden phenomenon", after natural deposits
were found "in France at Osbann (BasRhin), the
Parc (l'Ain) and the Puy-de-la-Poix (Puy-de-Dome)",
although it could also be made artificially.[31] One
of the earliest uses in France was the laying of about 24,000 square yards of
Seyssel asphalt at the Place de la Concorde in 1835.[32]
Photography and art[edit]
Bitumen was used in early photographic technology.
In 1826 or 1827, it was used by French scientist Joseph Nicéphore Niépce to make the oldest surviving photograph from nature.
The bitumen was thinly coated onto a pewter plate
which was then exposed in a camera. Exposure to light hardened the bitumen and
made it insoluble, so that when it was subsequently rinsed with a solvent only
the sufficiently light-struck areas remained. Many hours of exposure in the
camera were required, making bitumen impractical for ordinary photography, but
from the 1850s to the 1920s it was in common use as a photoresist in
the production of printing plates for various photomechanical printing
processes.[33][34][not in citation given]
Bitumen was the nemesis of many artists during the
19th century. Although widely used for a time, it ultimately proved unstable
for use in oil painting, especially when mixed with the most common diluents,
such as linseed oil, varnish and turpentine. Unless thoroughly diluted, bitumen
never fully solidifies and will in time corrupt the other pigments with which
it comes into contact. The use of bitumen as a glaze to set in shadow or mixed
with other colors to render a darker tone resulted in the eventual deterioration
of many paintings, for instance those of Delacroix. Perhaps the most famous example of the
destructiveness of bitumen is Théodore Géricault's Raft of the Medusa (1818–1819), where his
use of bitumen caused the brilliant colors to degenerate into dark greens and
blacks and the paint and canvas to buckle.[35]
Early use in the United Kingdom[edit]
Among the earlier uses of asphalt/bitumen in the
United Kingdom was for etching. William Salmon's Polygraphice (1673)
provides a recipe for varnish used in etching, consisting of three ounces of
virgin wax, two ounces of mastic, and one ounce of asphaltum.[36] By
the fifth edition in 1685, he had included more asphaltum recipes from other
sources.[37]
The first British patent for the use of
asphalt/bitumen was 'Cassell's patent asphalte or bitumen' in 1834.[31] Then
on 25 November 1837, Richard Tappin Claridge patented the
use of Seyssel asphalt (patent #7849), for use in asphalte pavement,[38][39] having
seen it employed in France and Belgium when visiting with Frederick Walter Simms, who worked with him
on the introduction of asphalt to Britain.[40][41] Dr
T. Lamb Phipson writes that his father, Samuel Ryland Phipson, a friend of
Claridge, was also "instrumental in introducing the asphalte pavement (in
1836)".[42] Indeed,
mastic pavements had been previously employed at Vauxhall by
a competitor of Claridge, but without success.[32]
In 1838, Claridge obtained patents in Scotland on
27 March, and Ireland on 23 April, and in 1851 extensions were sought for all
three patents, by the trustees of a company previously formed by Claridge.[31][43][44][45] This
was Claridge's Patent Asphalte Company, formed in 1838 for the
purpose of introducing to Britain "Asphalte in its natural state from the
mine at Pyrimont Seysell in France",[46] and
"laid one of the first asphalt pavements in Whitehall".[47] Trials
were made of the pavement in 1838 on the footway in Whitehall, the stable at
Knightsbridge Barracks,[46][48] "and
subsequently on the space at the bottom of the steps leading from Waterloo
Place to St. James Park".[48] "The
formation in 1838 of Claridge's Patent Asphalte Company (with a distinguished
list of aristocratic patrons, and Marc and Isambard Brunel as, respectively, a
trustee and consulting engineer), gave an enormous impetus to the development
of a British asphalt industry".[44] "By
the end of 1838, at least two other companies, Robinson's and the Bastenne
company, were in production",[49] with
asphalt being laid as paving at Brighton, Herne Bay, Canterbury, Kensington,
the Strand, and a large floor area in Bunhill-row, while meantime Claridge's Whitehall
paving "continue(d) in good order".[50]
In 1838, there was a flurry of entrepreneurial
activity involving asphalt/bitumen, which had uses beyond paving. For example,
asphalt could also used for flooring, damp proofing in buildings, and for
waterproofing of various types of pools and baths, with these latter themselves
proliferating in the 19th century.[6][31][51] On
the London stockmarket, there were various claims as to the exclusivity of
asphalt quality from France, Germany and England. And numerous patents were
granted in France, with similar numbers of patent applications being denied in
England due to their similarity to each other. In England, "Claridge's was
the type most used in the 1840s and 50s"[49]
In 1914, Claridge's Company entered into a joint
venture to produce tar-bound
macadam,[52] with
materials manufactured through a subsidiary company called Clarmac Roads Ltd.[53] Two
products resulted, namely Clarmac, and Clarphalte, with
the former being manufactured by Clarmac Roads and the latter by Claridge's
Patent Asphalte Co., although Clarmac was more widely used.[54][note 1] However,
the First World War impacted financially on the
Clarmac Company, which entered into liquidation in 1915.[56][57] The
failure of Clarmac Roads Ltd had a flow-on effect to Claridge's Company, which
was itself compulsorily wound up,[58] ceasing
operations in 1917,[59][60] having
invested a substantial amount of funds into the new venture, both at the
outset,[58] and
in a subsequent attempt to save the Clarmac Company.[56]
Early use in the US[edit]
The first use of asphalt/bitumen in the New World
was by indigenous peoples. On the west coast, as early as the 13th century, the Tongva, Luiseño andChumash peoples
collected the naturally occurring asphalt/bitumen that seeped to the surface
above underlying petroleum deposits. All three used the substance as an
adhesive. It is found on many different artifacts of tools and ceremonial
items. For example, it was used on rattles to adhere gourds or
turtle shells to rattle handles. It was also used in decorations. Small round
shell beads were often set in asphaltum to provide decorations. It was used as
a sealant on baskets to make them watertight for carrying water. Asphaltum was used
also to seal the planks on ocean-going canoes.
Roads in the US have been paved with materials
that include asphalt/bitumen since at least 1870, when a street in front of the
Newark, NJ City Hall was paved. In many cases, these early pavings were made from
naturally occurring "bituminous rock", such as at Ritchie Mines in
Macfarlan in Ritchie County, West Virginia from
1852 to 1873. In 1876, asphalt-based paving was used to pave Pennsylvania
Avenue in Washington, DC, in time for the celebration of the national
centennial.[61] Asphalt/bitumen
was also used for flooring, paving and waterproofing of baths and swimming
pools during the early 20th century, following similar trends in Europe.[51]
Early use in Canada[edit]
Canada has the world's largest deposit of natural
bitumen in the Athabasca oil sands and Canadian First
Nations along the Athabasca
River had long used it to waterproof their canoes. In 1719, a Cree Indian named
Wa-Pa-Su brought a sample for trade to Henry
Kelsey of the Hudson’s Bay Company, who was the first
recorded European to see it. However, it wasn't until 1787 that fur trader and
explorer Alexander MacKenzie saw the
Athabasca oil sands and said, "At about 24 miles from the fork (of the
Athabasca and Clearwater Rivers) are some bituminous fountains into which a
pole of 20 feet long may be inserted without the least resistance."[16]
The value of the deposit was obvious from the
start, but the means of extracting the bitumen were not. The nearest town, Fort McMurray, Alberta was a small fur
trading post, other markets were far away, and transportation costs were too
high to ship the raw bituminous sand for paving. In 1915, Sidney Ells of the
Federal Mines Branch experimented with separation techniques and used the
bitumen to pave 600 feet of road in Edmonton,
Alberta. Other roads in Alberta were paved with oil sands, but it was
generally not economic. During the 1920s Dr. Karl A. Clark of the Alberta Research Council patented a
hot water oil separation process and entrepreneur Robert C. Fitzsimmons[62] built
the Bitumount oil
separation plant, which between 1925 and 1958 produced up to 300 barrels
(50 m3) per day of bitumen using Dr. Clark's method. Most of
the bitumen was used for waterproofing roofs, but other uses included fuels,
lubrication oils, printers ink, medicines, rust and acid-proof paints,
fireproof roofing, street paving, patent leather, and fence post preservatives.[16] Eventually
Fitzsimmons ran out of money and the plant was taken over by the Alberta
government. Today the Bitumount plant is a Provincial Historic Site.[63]
Modern use[edit]
The road
surface is removed and a new bitumen layer is added
Rolled asphalt concrete[edit]
Main article: Asphalt
concrete
The largest use of asphalt/bitumen is for making asphalt
concrete for road surfaces and accounts for approximately 85% of the
asphalt consumed in the United States. Asphalt concrete pavement mixes are
typically composed of 5% asphalt/bitumen cement and 95% aggregates (stone,
sand, and gravel). Due to its highly viscous nature, asphalt/bitumen cement
must be heated so it can be mixed with the aggregates at the asphalt mixing
facility. The temperature required varies depending upon characteristics of the
asphalt/bitumen and the aggregates, but warm-mix asphalt technologies allow producers
to reduce the temperature required. There are about 4,000 asphalt concrete
mixing plants in the U.S., and a similar number in Europe.[64]
When maintenance is performed on asphalt
pavements, such as milling to remove a worn or damaged surface,
the removed material can be returned to a facility for processing into new
pavement mixtures. The asphalt/bitumen in the removed material can be
reactivated and put back to use in new pavement mixes.[65] With
some 95% of paved roads being constructed of or surfaced with asphalt,[66] a
substantial amount of asphalt pavement material is reclaimed each year.
According to industry surveys conducted annually by the Federal Highway Administration and
the National Asphalt Pavement Association, more than 99% of the asphalt removed
each year from road surfaces during widening and resurfacing projects is reused
as part of new pavements, roadbeds, shoulders and embankments.[67]
Asphalt concrete paving is widely used in airports
around the world. Due to the sturdiness and ability to be repaired quickly, it
is widely used for runways dedicated to aircraft landing and taking off.
Mastic asphalt[edit]
Mastic
asphalt is a type of asphalt which differs from dense graded asphalt (asphalt
concrete) in that it has a higher asphalt/bitumen (binder)
content, usually around 7–10% of the whole aggregate mix, as opposed to rolled
asphalt concrete, which has only around 5% added asphalt/bitumen. This
thermoplastic substance is widely used in the building industry for
waterproofing flat roofs and tanking underground. Mastic asphalt is heated to a
temperature of 210 °C (410 °F) and is spread in layers to form an
impervious barrier about 20 millimeters (0.79 inches) thick.
Asphalt emulsion[edit]
A number of technologies allow asphalt/bitumen to
be mixed at much lower temperatures. These involve mixing with petroleum
solvents to form "cutbacks" with reduced melting point, or mixtures
with water to turn the asphalt/bitumen into an emulsion.
Asphalt emulsions contain up to 70% asphalt/bitumen and typically less than
1.5% chemical additives. There are two main types of emulsions with different
affinity for aggregates, cationic and anionic. Asphalt
emulsions are used in a wide variety of applications. Chipseal involves
spraying the road surface with asphalt emulsion followed by a layer of crushed
rock, gravel or crushed slag. Slurry seal involves the creation of a mixture of
asphalt emulsion and fine crushed aggregate that is spread on the surface of a
road. Cold-mixed asphalt can also be made from asphalt emulsion to create
pavements similar to hot-mixed asphalt, several inches in depth and asphalt
emulsions are also blended into recycled hot-mix asphalt to create low-cost
pavements.
Synthetic crude oil[edit]
Main article: Synthetic crude oil
See also: Petroleum production in Canada
Synthetic crude oil, also known as syncrude, is
the output from a bitumen upgrader facility used in connection with oil sand
production in Canada. Bituminous sands are mined using enormous (100 ton
capacity) power shovels and loaded into even larger (400
ton capacity) dump trucks for movement to an upgrading facility.
The process used to extract the bitumen from the sand is a hot water process
originally developed by Dr. Karl Clark of the University of Alberta during the 1920s.
After extraction from the sand, the bitumen is fed into a bitumen upgrader which
converts it into a light crude oil equivalent. This synthetic
substance is fluid enough to be transferred through conventional oil
pipelines and can be fed into conventional oil
refineries without any further treatment. By 2015 Canadian bitumen
upgraders were producing over 1 million barrels (160×103 m3)
per day of synthetic crude oil, of which 75% was exported to oil refineries in
the United States.[68]
In Alberta, five bitumen upgraders produce
synthetic crude oil and a variety of other products: The Suncor
Energy upgrader near Fort McMurray, Albertaproduces synthetic
crude oil plus diesel fuel; the Syncrude
Canada, Canadian Natural Resources, and Nexen upgraders
near Fort McMurray produce synthetic crude oil; and the Shell Scotford
Upgrader near Edmonton produces synthetic crude oil plus an
intermediate feedstock for the nearby Shell Oil Refinery.[69] A
sixth upgrader, under construction in 2015 near Redwater,
Alberta, will upgrade half of its crude bitumen directly to diesel fuel,
with the remainder of the output being sold as feedstock to nearby oil
refineries and petrochemical plants.[70]
Non-upgraded crude bitumen[edit]
See also: Western Canadian Select
Canadian bitumen does not differ substantially
from oils such as Venezuelan extra-heavy and Mexican heavy
oil in chemical composition, and the real difficulty is moving the
extremely viscous bitumen through oil
pipelines to the refinery. Many modern oil refineries are extremely
sophisticated and can process non-upgraded bitumen directly into products such
as gasoline, diesel fuel, and refined asphalt without any preprocessing. This
is particularly common in areas such as the US Gulf coast,
where refineries were designed to process Venezuelan and Mexican oil, and in
areas such as the US Midwestwhere refineries were rebuilt to process heavy oil as
domestic light oil production declined. Given the choice, such heavy oil
refineries usually prefer to buy bitumen rather than synthetic oil because the
cost is lower, and in some cases because they prefer to produce more diesel
fuel and less gasoline.[69] By
2015 Canadian production and exports of non-upgraded bitumen exceeded that of
synthetic crude oil at over 1.3 million barrels (210×103 m3)
per day, of which about 65% was exported to the United States.[68]
Because of the difficulty of moving crude bitumen
through pipelines, non-upgraded bitumen is usually diluted with natural-gas condensate in a form calleddilbit or
with synthetic crude oil, called synbit. However,
to meet international competition, much non-upgraded bitumen is now sold as a
blend of multiple grades of bitumen, conventional crude oil, synthetic crude
oil, and condensate in a standardized benchmark product such as Western Canadian Select. This sour, heavy
crude oil blend is designed to have uniform refining characteristics to compete
with internationally marketed heavy oils such as Mexican Mayanor Arabian Dubai
Crude.[69]
Other uses[edit]
Roofing
shingles account for most of the remaining asphalt/bitumen
consumption. Other uses include cattle sprays, fence-post treatments, and
waterproofing for fabrics. Asphalt/bitumen is used to make Japan
black, a lacquer known especially for its use on iron and steel,
and it is also used in paint and marker inks by some graffiti supply companies
to increase the weather resistance and permanence of the paint or ink, and to
make the color much darker.[citation needed] Asphalt/bitumen
is also used to seal some alkaline batteries during the manufacturing process.
Production[edit]
Picture of typical asphalt plant for making
asphalt.
About 40,000,000 tons were produced in 1984[needs update].
It is obtained as the "heavy" (i.e., difficult to distill) fraction.
Material with a boiling point greater than around 500 °C is
considered asphalt. Vacuum distillation separates it from the other components
in crude oil (such as naphtha, gasoline and diesel).
The resulting material is typically further treated to extract small but
valuable amounts of lubricants and to adjust the properties of the material to
suit applications. In ade-asphalting unit, the crude asphalt is treated
with either propane or butane in a supercritical phase to extract the lighter
molecules, which are then separated. Further processing is possible by
"blowing" the product: namely reacting it with oxygen. This step
makes the product harder and more viscous.[8]
Asphalt/bitumen is typically stored and
transported at temperatures around 150 °C (302 °F). Sometimes diesel oil orkerosene are
mixed in before shipping to retain liquidity; upon delivery, these lighter
materials are separated out of the mixture. This mixture is often called
"bitumen feedstock", or BFS. Some dump trucks route
the hot engine exhaust through pipes in the dump body to keep the material
warm. The backs of tippers carrying asphalt/bitumen, as well as some handling
equipment, are also commonly sprayed with a releasing agent before filling to
aid release. Diesel oil is no longer used as a release
agent due to environmental concerns.
From oil sands[edit]
See also: oil sands
Naturally occurring crude asphalt/bitumen
impregnated in sedimentary rock is the prime feed stock for petroleum
production from "Oil sands", currently under development in Alberta,
Canada. Canada has most of the world's supply of natural asphalt/bitumen,
covering 140,000 square kilometres[71] (an
area larger than England), giving it the second-largest proven oil
reserves in the world. The Athabasca oil sands is the largest
asphalt/bitumen deposit in Canada and the only one accessible to surface
mining, although recent technological breakthroughs have resulted in deeper
deposits becoming producible by in situmethods.
Because of oil price increases after 2003,
producing bitumen became highly profitable, but as a result of the decline
after 2014 it became uneconomic to build new plants again. By 2014, Canadian
crude asphalt/bitumen production averaged about 2.3 million barrels (370,000 m3)
per day and was projected to rise to 4.4 million barrels (700,000 m3)
per day by 2020.[72] The
total amount of crude asphalt/bitumen in Alberta which could be extracted is
estimated to be about 310 billion barrels (50×109 m3),[11] which
at a rate of 4,400,000 barrels per day (700,000 m3/d) would
last about 200 years.
Alternatives and bioasphalt[edit]
Main articles: Peak oil, Global
warming and Bioasphalt
Although uncompetitive economically,
asphalt/bitumen can be made from nonpetroleum-based renewable resources such as
sugar, molasses and
rice, corn and potato starches. Asphalt/bitumen can also be made from waste material
by fractional distillation of used motor oil,
which is sometimes otherwise disposed of by burning or dumping into landfills.
Use of motor oil may cause premature cracking in colder climates, resulting in
roads that need to be repaved more frequently.[73]
Nonpetroleum-based asphalt/bitumen binders can be
made light-colored. Lighter-colored roads absorb less heat from solar
radiation, and have less surface heat than darker surfaces, reducing their
contribution to the urban
heat island effect.[74] Parking
lots that use asphalt alternatives are called green parking lots.
Natural bitumen[edit]
This section requires expansionwith:
description of other natural sources of bitumen. (May 2015)
|
Selenizza is a naturally occurring solid
hydrocarbon bitumen found in the native asphalt deposit of Selenice, in Albania, the
only European asphalt mine still in use. The rock asphalt is found in the form
of veins, filling cracks in a more or less horizontal direction. The bitumen
content varies from 83% to 92% (soluble in carbon disulphide), with a
penetration value near to zero and a softening point (ring & ball) around
120 °C. The insoluble matter, consisting mainly of silica ore, ranges from
8% to 17%.
The Albanian bitumen extraction has a long history
and was practiced in an organized way by the Romans. After centuries of
silence, the first mentions of Albanian bitumen appeared only in 1868, when the
Frenchman Coquand published the first geological
description of the deposits of Albanian bitumen. In 1875, the exploitation
rights were granted to the Ottoman government and in 1912, they were transferred
to the Italian company Simsa. Since 1945, the mine was exploited by the
Albanian government and from 2001 to date, the management passed to a French
company, which organized the mining process for the manufacture of the natural
bitumen on an industrial scale.[75]
Today the mine is predominantly exploited in an
open pit quarry but several of the many underground mines (deep and extending
over several km) still remain viable. The bitumen Selenizza is produced
primarily in granular form, after melting the asphalt pieces selected in the
mine.
Selenizza[76] is
mainly used as an additive in the road construction sector. It is mixed with
traditional bitumen to improve both the viscoelastic properties and the
resistance to ageing. It may be blended with the hot bitumen in tanks, but its
granular form allows it to be fed in the mixer or in the recycling ring of
normal asphalt plants. Other typical applications include the production of
mastic asphalts for sidewalks, bridges, car-parks and urban roads as well as
drilling fluid additives for the oil and gas industry. Selenizza is available
in powder or in granular material of various particle sizes and is packaged in
big bags or in thermal fusible polyethylene bags.
A Life Cycle Assessment (LCA) study of the
natural bitumen Selenizza compared with petroleum bitumen, has shown that the
environmental impact of the natural bitumen is about half the impact of the
road bitumen produced in oil refineries in terms of carbon dioxide emission.[77]
Occupational safety[edit]
People can be exposed to asphalt in the workplace
by breathing in fumes or skin absorption. The National
Institute for Occupational Safety and Health(NIOSH) has set a Recommended exposure limit (REL) of
5 mg/m3 over a 15-minute period.[78] Asphalt
is basically an inert material that must be heated or diluted to a point where
it becomes workable for the production of materials for paving, roofing, and
other applications. In examining the potential health hazards associated with
asphalt, the International Agency for
Research on Cancer (IARC) determined that it is the application
parameters, predominantly temperature, that effect occupational exposure and
the potential bioavailable carcinogenic hazard/risk of the asphalt emissions.[79] In
particular, temperatures greater than 199 °C (390 °F), were shown to
produce a greater exposure risk than when asphalt was heated to lower
temperatures, such as those typically used in asphalt pavement mix production
and placement.[80]
Etymology[edit]
The word asphalt is derived from
the late Middle English, in turn from French asphalte, based on Late Latin asphalton, asphaltum,
which is the latinisation of the Greek ἄσφαλτος
(ásphaltos, ásphalton), a word meaning
"asphalt/bitumen/pitch",[81] which
perhaps derives from ἀ-, "without" and σφάλλω (sfallō),
"make fall".[82] Note
that in French, the term asphalte is used for naturally
occurring bitumen-soaked limestone deposits, and for specialised manufactured
products with fewer voids or greater bitumen content than the "asphaltic
concrete" used to pave roads. It is a significant fact that the first use
of asphalt by the ancients was in the nature of a cement for securing or
joining together various objects, and it thus seems likely that the name itself
was expressive of this application. Specifically Herodotus mentioned
that bitumen was brought to Babylon to build its gigantic fortification wall.[83] From
the Greek, the word passed into late Latin, and thence into French (asphalte)
and English ("asphaltum" and "asphalt").
The expression "bitumen" originated in
the Sanskrit, where we find the words jatu, meaning
"pitch," and jatu-krit, meaning "pitch
creating", "pitch producing" (referring to coniferous or
resinous trees). The Latin equivalent is claimed by some to be originally gwitu-men (pertaining
to pitch), and by others, pixtumens(exuding or bubbling pitch),
which was subsequently shortened to bitumen, thence passing via
French into English. From the same root is derived the Anglo Saxon word cwidu (mastix),
the German word Kitt (cement or mastic) and the old Norse word kvada.[84]
Modern usage[edit]
An asphalt mixing plant for hot aggregate
In British
English, the word 'asphalt' is used to refer to a mixture of mineral
aggregate and asphalt/bitumen (also called tarmac in
common parlance). When bitumen is mixed with clay it is usually called asphaltum.[85] The
earlier word 'asphaltum' is now archaic and not commonly used.[citation needed] In American
English, 'asphalt' is equivalent to the British 'bitumen'. However,
'asphalt' is also commonly used as a shortened form of 'asphalt
concrete' (therefore equivalent to the British 'asphalt' or 'tarmac'). In Australian English, bitumen is often used as the
generic term for road surfaces. In Canadian
English, the word bitumen is used to refer to the vast Canadian deposits of
extremely heavy crude oil,[71] while
asphalt is used for the oil
refinery product used to pave roads and manufacture roof
shingles and various waterproofing products. Diluted bitumen (diluted
with naphtha to
make it flow in pipelines) is known as dilbit in the
Canadian petroleum industry, while bitumen "upgraded"
to synthetic crude oil is known as syncrude and
syncrude blended with bitumen as synbit.[72] Bitumen
is still the preferred geological term for naturally occurring deposits of the
solid or semi-solid form of petroleum. Bituminous rock is a form of sandstone
impregnated with bitumen. The tar sands of Alberta,
Canada are a similar material.
See also[edit]
·
Blacktop
·
Duxit
·
Tarmac
·
Macadam
·
Tar
·
Sealcoat
Notes[edit]
1. Jump up^ The Building News and Engineering
Journal contains photographs of the following roads where Clarmac was
used, being "some amongst many laid with 'Clarmac'": Scott's Lane, Beckenham;
Dorset Street, Marylebone; Lordswood Road, Birmingham;
Hearsall Lane, Coventry; Valkyrie Avenue, Westcliff-on-Sea;
and Lennard Road,Penge.[55]
References[edit]
6. ^ Jump up
to:a b c d e Abraham,
Herbert (1938). Asphalts and
Allied Substances: Their Occurrence, Modes of Production, Uses in the Arts, and
Methods of Testing(4th ed.). New York: D. Van Nostrand Co. Retrieved 16
November 2009. Full text at Internet Archive (archive.org)
8. ^ Jump up to:a b c Anja
Sörensen and Bodo Wichert "Asphalt and Bitumen" in Ullmann's
Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2009.doi:10.1002/14356007.a03_169.pub2http://www.qrpoil.com/site/?bitumen
9. Jump up^ "Oil
Sands – Glossary". Oil Sands Royalty Guidelines. Government of
Alberta. 2008. Archived from the original on 1
November 2007. Retrieved2 February 2008.
10. Jump up^ Walker, Ian C. (1998), Marketing
Challenges for Canadian Bitumen (PDF), Tulsa, OK: International Centre
for Heavy Hydrocarbons, 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.
11. ^ Jump up to:a b c "ST98-2015:
Alberta's Energy Reserves 2014 and Supply/Demand Outlook 2015–2024" (PDF). Statistical
Reports (ST). Alberta Energy Regulator. 2015. Retrieved 19 January 2016.
12. Jump up^ Muhammad Abdul Quddus (1992).
"Catalytic Oxidation of Asphalt". thesis submitted to
Department of Applied Chemistry; University of Karachi. Pakistan: Higher
Education Commission Pakistan: Pakistan Research Repository. p. 6, in ch.2
pdf.
14. ^ Jump up to:a b Bunger,
J.; Thomas, K.; Dorrence, S. (1979). "Compound types and properties of
Utah and Athabasca tar sand bitumens". Fuel 58 (3):
183–195.doi:10.1016/0016-2361(79)90116-9.
15. Jump up^ Selby, D.; Creaser, R. (2005).
"Direct radiometric dating of hydrocarbon deposits using rhenium-osmium
isotopes". Science 308: 1293–1295.doi:10.1126/science.1111081.
16. ^ Jump up
to:a b c d e "Facts
about Alberta’s oil sands and its industry" (PDF). Oil Sands
Discovery Centre. Retrieved 19 January 2015.
17. Jump up^ T. Boden and B. Tripp (2012). Gilsonite
Veins of the Uinta Basin, Utah. Utah, US: Utah Geological Survey, Special Study
141.
24. Jump up^ Pringle, Heather Anne (2001). The
Mummy Congress: Science, Obsession, and the Everlasting Dead. New York, NY:
Barnes & Noble Books. pp. 196–197.ISBN 0-7607-7151-0.
25. Jump up^ Pedanius Dioscorides. De
Materia Medica.. Original written ca. 40 AD, translated by Goodyer (1655) [5] or (Greek/Latin) compiled
by Sprengel (1829) [6] p.
100 (p. 145 in PDF).
26. Jump
up^ Connan,
Jacques; Nissenbaum, Arie (2004). "The organic geochemistry of the Hasbeya
asphalt (Lebanon): comparison with asphalts from the Dead Sea area and
Iraq". Organic Geochemistry 35 (6): 775–789.doi:10.1016/j.orggeochem.2004.01.015. ISSN 0146-6380.
27. Jump up^ Arie Nissenbaum (May 1978). "Dead
Sea Asphalts—Historical Aspects [free abstract]". AAPG Bulletin 62 (5):
837–844. doi:10.1306/c1ea4e5f-16c9-11d7-8645000102c1865d.
28. Jump up^ The Megalithic Portal and
Megalith Map. "C.Michael
Hogan (2008) ''Morro Creek'', ed. by A. Burnham". Megalithic.co.uk.
Retrieved 27 August 2013.
29. Jump up^ Africa and the Discovery of America,
Volume 1, page 183, Leo Wiener, BoD – Books on Demand, 1920 reprinted in
2012, ISBN
978-3864034329
30. Jump
up^ "Nothing
New under the Sun (on French asphaltum use in 1621)". The
Mechanic's magazine, museum, register, journal and gazette 29.
London: W.A. Robertson. 7 April – 29 September 1838. p. 176.
31. ^ Jump up
to:a b c d Miles,
Lewis (2000). "Section 10.6: Damp Proofing". in
Australian Building: A Cultural Investigation (PDF). p. 10.06.1.
Retrieved 11 November2009.. Note: different sections of Miles' online
work were written in different years, as evidenced at the top of each page (not
including the heading page of each section). This particular section appears to
have been written in 2000
32. ^ Jump up
to:a b R.J.
Forbes (1958), Studies
in Early Petroleum History, Leiden,
Netherlands: E.J. Brill, p. 24, retrieved 10 June 2010
33. Jump up^ Niépce Museum history pages. Retrieved
27 October 2012. Archived 3
August 2007 at the Wayback Machine.
34. Jump up^ The First
Photograph (Harry Ransom Center, University of Texas at Austin). Retrieved
27 October 2012.
35. Jump
up^ Spiegelman,
Willard (2009-08-21). "Revolutionary
Romanticism: 'The Raft of the Medusa' brought energy to French art". The Wall Street Journal (New York
City). Retrieved 2016-01-27.
36. Jump
up^ Salmon,
William (1673). Polygraphice;
Or, The Arts of Drawing, Engraving, Etching, Limning, Painting, Washing,
Varnishing, Gilding, Colouring, Dying, Beautifying and Perfuming (Second
ed.). London: R. Jones. p. 81.
37. Jump
up^ Salmon,
William (1685), Polygraphice;
Or, The Arts of Drawing, Engraving, Etching, Limning, Painting, Washing,
Varnishing, Gilding, Colouring, Dying, Beautifying and Perfuming (5th
ed.), London: R. Jones, pp. 76–77, retrieved18 August 2010 Text
at Internet Archive
38. Jump
up^ "Specification
of the Patent granted to Richard Tappin Claridge, of the County of Middlesex,
for a Mastic Cement, or Composition applicable to Paving and Road making,
covering Buildings and various purposes". Journal
of the Franklin Institute of the State of Pennsylvania and Mechanics' Register.
Vol. 22. London: Pergamon Press. July 1838. pp. 414–418. Retrieved18
November 2009.
39. Jump
up^ "Comments
on asphalt patents of R.T. Claridge, Esq". Notes
and Queries: A medium of intercommunication for Literary Men, General Readers,
etc. Ninth series. Volume XII, July–December, 1903 (9th S. XII, 4 July
1903). London: John C. Francis. 20 January 1904. pp. 18–19. Writer
is replying to note or query from previous publication, cited as 9th S.
xi. 30
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up^ "Obituary of
Frederick Walter Simms". Monthly Notices of
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and county engineer (London) 122 (3278 & 3279):
1437–1440 & 1472–1475Snippet
view: Simms & Claridge p.1439
42. Jump up^ Phipson, Dr T. Lamb (1902). Confessions of a
Violinist: Realities and Romance. London: Chatto & Windus. p. 11.
Retrieved 26 November 2009.Full text at Internet Archive
(archive.org)
44. ^ Jump
up to:a b Hobhouse,
Hermione (General Editor) (1994). "British History Online".'Northern
Millwall: Tooke Town', Survey of London: volumes 43 and 44: Poplar, Blackwall
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Sources[edit]
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Barth, Edwin J., Asphalt: Science and
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·
Forbes, R.J. (1993) [Reprint of 1964 ed.], Studies
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