SEPARATION OF HYDROCARBONS FROM OIL SHALES AND TAR SANDS

EXTRACTION DES HYDROCARBURES EN PRESENCE DANS LES SCHISTES ET LES SABLES BITUMINEUX

English Abstract

SEPARATION OF HYDROCARBONS FROM
OIL SHALES AND TAR SANDS
Abstract of the Disclosure
An efficient and practical process is provided, permitting
greatly increased recovery of hydrocarbons from oil shales and
tar sands. Steps involved include mixing oil shale or tar sand in
water, with pulverized coal, to form an amalgam, and separation
of water to be reused in the process. The separated amalgam contains
the hydrocarbons of the shale or sand and constituents of coal in
which mineral matter content is considerably reduced.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process of separating hydrocarbons from oil shales or
tar sands, which process comprises grinding oil shale or tar sand
in water and reducing the shale or sand to a fine particle size,
adding pulverized coal to the mixture of shale or sand and water
and agitating to form an amalgam which contains the hydrocarbons
of the oil shale or tar sand and the coal, separating the amalgam
from the resulting mixture and further separating the water and
mineral matter for reuse of the water in the process.
2. A process of separating hydrocarbons from oil shales
or tar sands, which process comprises grinding oil shale or tar
sand in water, adding pulverized bituminous coal in water sus-
pension to the shale or sand suspension formed in water while
simultaneously separating the carbonaceous matter from the gangue
of shale or tar sand and forming an amalgam of said coal and the
carbonaceous matter from said oil shale or tar sand, separating
the amalgam from the water, settling out the mineral matter of
the shale or sand and of the coal, and reusing the water in the
subsequent treatment of oil shale or tar sand.
3. A process of separating hydrocarbons from oil shales or
tar sands, which process comprises mixing finely divided oil shale
or tar sand and pulverized coal in water to form an amalgam con-
taining carbonaceous matter of the oil shale or tar sand and the
coal, and separating the amalgam from the resulting mixture.

Description

Background of the Invention
. i.~`;` ¦ In~the recovery of carbonaceous content of coals in the past,
aside from the use of heat, oils or llquid solvents were applied,
i ¦ such as, benzol, crude oil, gasoline and others. In the well known
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Trent process, such oils or liquids were mixed with the coal sus-
pended in water to separate the carbonaceous matter from ash. The re-
coveryofhydrocarbons from shale and tar sands in the past has
been restricted essentially to the use of heat, with attendant com-
bustion and severe loss of hydrocarbons. In the process claimed
hereinbelow, hydrocarbon matter is separated from shale in the
presence of coal but no oils or liquid hydrocarbons are used to
accomplish the separation.
Summary of the Invention
The present invention relates to improvements in methods of
separating hydrocarbons from oil shales or tar sands with coal as an
agent. There is in effect a simultaneous removal of carbonaceous
matter from the coal and from the oil shale or tar sand in the course
of the treatment.
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The invention is based on the discovery of a method of
separating the hydrocarbons from the mineral constituents of oil
shale or tar sand in an aqueous medium by means of coal, in which
method the water is reused and the loss of water is substantially
reduced in the processing of the oil shale or tar sand.
The hydrocarbons in the oil shale or tar sand may be
separated while avoiding the use of heat and combustion for the
separation.
According to the invention, there is provided a process
of separating hydrocarbons from oil shales or tar sands, which
process comprises grinding oil shale or tar sand in water and
reducing the shale or sand to a fine particle size, adding
pulverized coal to the mixture of shale or sand and water and
agitating to form an amalgam which contains the hydrocarbons of
the oil shale or tar sand and the coal, separating the amalgam
from the resulting mixture, and further separating the water and
mineral matter for reuse of the water in the process.
The invention also provides a process of separating
hydrocarbons from oil shales or tar sands, which process com-
prises grinding oil shale or tar sand in water, adding pulverizedbituminous coal in water suspension to the shale or sand suspension
formed in water while simultaneously separating the carbonaceous
matter from the gangue of shale or tar sand and forming an amalgam
of said coal and the carbonaceous matter from said oil shale or
tar sand, separating the amalgam from the water, settling out the
mineral matter of the shale or sand and of the coal, and reusing
the water in the subsequent treatment of oil shale or tar sand.
Finally, the invention provides a process of separating
hydrocarbons from oil shales or tar sands, which process comprises
mixing finely divided oil shale or tar sand and pulverized coal
in water to form an amalgam containing carbonaceous matter of the
oil shale or tar sand and the coal, and separating the amalgam
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from the resulting mixture.
In a preferred process of the present invention the
following steps are employed:
1. Oil shale or tar sand is ground in water.
2. Pulverized coal is added. The coal is preferably in
suspension in water (slurry) when added to the material of Step 1.
3. The mixture is agitated to form an amalgam of hydro-
carbons initially in the shale or sand, and in the coal.
4. The separated amalgam containing hydrocarbons from the
oil shale or tar sand and from coal, is usable in subsequent
treatments, such as coking, etc.
The particle size of the oil shale or tar sand and the
coal may be 100 mesh or smaller. Bituminous and subbituminous
; coals are more suited than anthracite or lignite because the
latter two coals are not likely to yield satisfactory results.
The said bituminous coals and oil shales are considered to be
plentiful in western United States. In some areas in which oil
shales and tar sands occur, water is scarce. The processing
waters from the present process may be passed into settling
ponds. A considerably lower evaporation loss occurs since in
the above described process an oily surface film is produced
on the ponds.
Besides coking the amalgam to produce a coke product,
and obtaining the oil values of the oil shales or tar sands in
the form of oils and gas, the amalgam may be completely hydrogen-
ated. Also, when the amalgam is obtained with a sufficiently high
oil content, so that it flows at elevated temperatures, it is
possible to deliver it by pipeline to be used as a fuel in power
plants and various large industries. Serious losses of large
amounts of water in coal slurry deliveries, as are currently ad-
vocated, are likeIy to occur.