SOURCES OF ASPHALT (BITUMEN)
Asphalt is obtained as the ultimate bottom product of a vaccum
distillation column(VDU) .
The residums obtained from VDU may still contain some oil,
but further distillation of it serves no use at all.
These residums are rich in asphalts and form the starting materials
for air blown bitumen process.
Asphalts are also obtained on a large scale from deasphalting
units.
Reduced...
