Asphalt yog cov kua dej uas muaj kuab heev nrog lub ntsej muag dub thiab soluble hauv carbon disulfide (cov kua kub-daj, tsw ntxhiab tsw). Lawv feem ntau muaj nyob rau hauv daim ntawv ntawm asphalt los yog tar.
Asphalt tuaj yeem muab faib ua peb hom: thee tar suab, roj av asphalt thiab ntuj asphalt: ntawm lawv, thee tar suab yog cov khoom lag luam ntawm coking. Petroleum asphalt yog cov seem tom qab distillation ntawm cov roj crude. Ntuj asphalt yog khaws cia hauv av, thiab qee qhov tsim cov pob zeb hauv av los yog sau rau ntawm lub ntiaj teb pob zeb.
Bitumen nyob rau hauv daim ntawv ntawm asphalt yog tau los ntawm refining crude roj los ntawm fractionation. Lawv muaj cov ntsiab lus kub hauv cov roj crude thiab yog cov khoom hnyav hauv cov roj crude, yog li lawv yuav pom nyob rau hauv qab ntawm fractionation towers.
Asphalt nyob rau hauv daim ntawv ntawm tar yog tau los ntawm kev kho cov organic teeb meem (feem ntau thee) los ntawm carbonization.
Asphalt feem ntau siv hauv kev tsim kho, xws li kev paving. Txoj kev paved asphalt thiab gravel yog hu ua asphalt txoj kev.