EXPLORATION, RECOVERY, AND TRANSPORTATION 87
Surface mining is the mining method that is currently being
used by Suncor Energy and Syncrude Canada Limited to recover
oil sand from the ground. Surface mining can be used in mineable
oil sand areas which lie under 75 meters (250 feet) or less of overburden material. Only 7% of the Athabasca Oil Sands deposit can
be mined using the surface mining technique, as the other 93% of
the deposit has more than 75 meters of overburden. This other 93%
will have to be mined using different mining techniques.
The first step in surface mining is the removal of muskeg and
overburden. Muskeg is a water-soaked area of decaying plant material that is one to three meters thick and lies on top of the overburden material. Before the muskeg can be removed it must be drained
of its water content. The process can take up to three years to complete. Once the muskeg has been drained and removed, the overburden must also be removed. Overburden is a layer of clay, sand,
and silt that lies directly above the oil sands deposit. Overburden is
used to build dams and dykes around the mine and will eventually
be used for land reclamation projects. When all of the overburden is
removed, the oil sand is exposed and is ready to be mined.
There are two methods of mining currently in use in the Athabasca
Oil Sands. Suncor Energy uses the truck-and-shovel method of mining whereas Syncrude uses the truck and shovel method of mining,
as well as draglines and bucket-wheel reclaimers. These enormous
draglines and bucket-wheels are being phased out and soon will
be completely replaced with large trucks and shovels. The shovel
scoops up the oil sand and dumps it into a heavy hauler truck. The
heavy hauler truck takes the oil sand to a conveyor belt that transports the oil sand from the mine to the extraction plant.
Tar sand, as mined commercially in Canada, contains an average of
10 to 12% bitumen, 83 to 85% mineral matter and 4 to 6% water. A film
of water coats most of the mineral matter, and this property permits
extraction by the hot-water process, which is, to date, the only successful commercial process to be applied to bitumen recovery from
mined tar sands in North America (Speight, 2008). Many process
options have been tested with varying degrees of success and one of
these options may even supersede the hot water process.
In the hot water extraction process, the tar sand feed is introduced into a conditioning drum. In this step the oil sand is heated,
mixed water, and agglomeration of the oil particles begins. The
conditioning is carried out in a slowly rotating drum that contains
a steam-sparging system for temperature control as well as mixing
Surface mining is the mining method that is currently being
used by Suncor Energy and Syncrude Canada Limited to recover
oil sand from the ground. Surface mining can be used in mineable
oil sand areas which lie under 75 meters (250 feet) or less of overburden material. Only 7% of the Athabasca Oil Sands deposit can
be mined using the surface mining technique, as the other 93% of
the deposit has more than 75 meters of overburden. This other 93%
will have to be mined using different mining techniques.
The first step in surface mining is the removal of muskeg and
overburden. Muskeg is a water-soaked area of decaying plant material that is one to three meters thick and lies on top of the overburden material. Before the muskeg can be removed it must be drained
of its water content. The process can take up to three years to complete. Once the muskeg has been drained and removed, the overburden must also be removed. Overburden is a layer of clay, sand,
and silt that lies directly above the oil sands deposit. Overburden is
used to build dams and dykes around the mine and will eventually
be used for land reclamation projects. When all of the overburden is
removed, the oil sand is exposed and is ready to be mined.
There are two methods of mining currently in use in the Athabasca
Oil Sands. Suncor Energy uses the truck-and-shovel method of mining whereas Syncrude uses the truck and shovel method of mining,
as well as draglines and bucket-wheel reclaimers. These enormous
draglines and bucket-wheels are being phased out and soon will
be completely replaced with large trucks and shovels. The shovel
scoops up the oil sand and dumps it into a heavy hauler truck. The
heavy hauler truck takes the oil sand to a conveyor belt that transports the oil sand from the mine to the extraction plant.
Tar sand, as mined commercially in Canada, contains an average of
10 to 12% bitumen, 83 to 85% mineral matter and 4 to 6% water. A film
of water coats most of the mineral matter, and this property permits
extraction by the hot-water process, which is, to date, the only successful commercial process to be applied to bitumen recovery from
mined tar sands in North America (Speight, 2008). Many process
options have been tested with varying degrees of success and one of
these options may even supersede the hot water process.
In the hot water extraction process, the tar sand feed is introduced into a conditioning drum. In this step the oil sand is heated,
mixed water, and agglomeration of the oil particles begins. The
conditioning is carried out in a slowly rotating drum that contains
a steam-sparging system for temperature control as well as mixing