Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
SEPAR~TIO~ OF BITUMINOUS MATERIAL FROM 'rAR SANDS
This invention relates to treatment o~ mix.tures of
bituminous, aqueous, and mineral matter of the type
commonly referred to as tar sands, to separate them into
bituminous and mineral fractions, by application oE
elec~romagnetic frequencies o~ the type commonly
referred to as microwaves.
It is an o~ject of the invention to provlde a
method of separating tar sand into two fraction~, one
fraction cantaining bituminous matter, the other
~raction containing mineral matter. These two fractions
are not neces-carily absolutes, the bituminous fraction
will contain a greater proportion o~ bi~uminous matter
than the original tar sand, while the ~ineral fraction
will contain a g~eater proportion of mineral matter than
the original ~ar sandO Desirably there will be no
apparent bitumen in the mineral fraction, and no
apparent mineral in the b ! tuminous fraction. More
desirably there will be negligible bitumen in the
mineral fraction, and negligible mineral in the
bituminous fraction.
The electroma~netic radiation used is depending on
definition and frequency, in that part of the
electromagnetic spec~rum bordering radio waves and
microwaves~ The usual definition of microwaves is that
portion of the el~ctromagnetic spestrum having
frequencies greater than thQse of radio waves and les5
than those of infrared waves. Microwaves are def,-ined as
having frequencies ranging from a lower limit of 100 MHz
(3 m), 300 MHz (1 m), or 1 GHz (30 cm),to an upper limit
of 300 GHz (1 mm) or 1000 GHz (0.3 mm). Radio waves are
usually defined as not including microwaves, but are
sometimes regarded as including microwave frequencies,
and having an upper frequency limit o~ 100 GHz (3 mm).
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Applicant has discovered that ~y treatm~t of tar
sand by electromagnetic radiatlon of selected wavelength
separation of bituminolls ancl mineral fractions can be
observed.
Tar sand also known as "oil sand" is understood to
mean in this applica~ion a naturally occurring mixture
of tar, water and mineral matter. The m:ineral matter is
usually a mixture of sand (95%), heavy minerals,
carbonates, and clay Minerals~ The tar is bituminous in
nature and typically comprises from about 5% to about
18% by weight of the mixture. Water typically comprises
about 2% to about 12% by weight of the mixture. Mineral
matter typically comprises about a3% by weight of the
mixture, variation from these figures may be observed.
The mineral matter includes sand grains and fines. The
sand grains are believed to form a nearly space filling
arrangement with about 65~ by volume of the sand, with
the bituminous material and water in the voids between
the sand grains, totalling about 35~ by volume of the
sand. The sand grains of the tar sand are wetted, the
grains can range from strongly water wetted, to strongly
oil (bitumen/tar) wetted, sands of intermediate
wettability are known to exist.
DESCRIPTION OF THE PRIOR ART
General applications of electromagnetic waves to
tar sands, oil shales and coals are known. Radio waves
may be applied directly, or as a fluctuating electric or
magnetic field, or by induction heating where an
electric current is applied to generate another electric
current in the material to be treated [as a primary coil
current in a transformer qenerates a secondary coil
current]. All these can be viewed as application of
electromagnetic waves loosely termed of "radio"
frequency. General use of such frequencies for heating
tar sand or oil shale in situ is taught by Rowland in
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U.S. Pa-tent 4,135,5'~9 ancl Dauphine in Canadiarl Patent
1,105,376, which utilize ~re~uencie~ between lO0
kiloher~z and 100 megahertz, ~or yeneral heating of oil
shales. The Fishers in Canadian Patents 994,694,
994,695 and 1,105,376 teach similar treatment of tar
sand by induction heating using alternatiny current o~
unspecified ~requencies, except that i~ i5 suggested
that normal 60 cycle AC could be used.
Radio and microwave frequency heating of oil
shales, tar sands and coals to liquefy, volatilize~ and
pyrolyze the bituminous or organic component is well
known. Microwaves are used to retort such materials by
~odge in U.S. Patent 2,542,028, Knapp in U.S. Patent
3,449,213 and 3,560,347, Stone in U.S. Patent 3,503,865,
Wallace in U.S. Patent 4,118,282, Dumbaugh et al in
Canadian Patent 1,108,081, Wall in U.S. Patent
4,376,034, Balint et al in U.S. Patent 4,419,214.
General frequencies are taught from 20 MHz to 1000 GHz,
specific frequencies applied were 20 MHz ~Hodge), 0.4 to
1000 MHz (Balint), 915 MHz (Wall, Balint), 900 to 2500
MHz (Balint), 2450 MHz (Wallace, Dumbaugh, Wall,) 5800
MHz (Balint), ~napp and Stone are indi~ferent to the
~requency applied as long as it is above 1000 MHz ~1
GHz~ (Stone) or allowed by the FCC (Knapp). Ergun in
U.S. Patent 3,463,310, teaches application o~ microwave
heating to the mineral component of coal to change its
magnetic proper~ies to allow separation by magnetic
means over a frequency range of 400 to 10,000 MHz.
Nadkarni, in U.S. Patent 4,408,999 treats oil shale or
coàl or the like in an acidic slurry with frequencies in
the 100 KHz to 100,000 MHz range with 1,000 to 3,000 MHz
preferred, which assists the solution o~ the mineral
component in the acidic slurry. Canadian Patent 448,231
issued May 4, 1948 to Clark, teaches to heat and mix
water with tar sand in a mill, -the water plus ail
~orming less than 30% weight of ~he mixture, air is
beaten into the resulting pulp, which is then washed in
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warm water. T~hi~h releases the oil a.~ a froth,
containing less than 5~ of the sand.
SUMMARY OF THE INVENTION
In a broad aspect the invention is directed to an
improved process o~ physical separation of tar sand
comprising bituminous, mineral an~ aqueous components
in~o upper bituminous and lower mineral fraction~. The
improvement is exposing the tar sand to microwave
radiation, at a temperature less than the boilin~ point
o~ water, in the absence of industrial solvent, and the
presence of added water, at a level sufficient to allow
the tar sand to separate by gravity into upper
bituminous and lower mineral fractions. The upper
bituminous fraction has a ~reater proportion of
bituminous matter than the tar sand, and the lower
mineral fraction has a greater proportion of mineral
matter than the tar sand. The microwave frequency i5 in
the ran~e of about 800 MHz to about 1700 MHz. Preferred
microwave ~requency ranges are 920+90 MHzr 1250+130 MHz
and 1540+150 M~z. The temperature i~ preferred to be
below the initial boiling point of water. Preferably
the added water i5 from about a quarter to about four
times the volume of the tar sand.
In another broad aspect the invention i5 directed
~o an improved process of physical separation o~ tar
sand having bituminous, mineral and aqueous components
30 into upper bituminous and lower mineral fractions. The
improvement is exposin~ the tar sand to microwave
radiation at a temperature less than the bolling poin-t
of water r in the absence of industrial solvent, and the
presence o~ added water, at a level su~ficient to allow
the tar sand to separate by gravity into upper
bituminous and lower mineral fractions. The upper
bituminous fraction has no apparent mineral matter, and
the lower mineral fraction has no apparent bituminous
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matter. Visually clean 3eparation appears to be
achieved. The microwave ~requency is ln the ran~0 of
about 800 MH2 to about 1700 M~z. Pre~erred microwave
frequency ranges are 920+90 MHz, 1~50+130 MHz and
l540+150 MHz. The temperature is preferred to be below
the initial boiling point o~ water. Preferably the
added water is from about a guarter to about four times
the volume of the tar sand.
lQ The original samples, in the initial observations,
separated fairly cleanly. Later attempts to reproduce
the exact conditions and results were not as successful,
although partîal separation wa~ achieved. The area from
which the original samples were taken, near Fort
McMurray, is often waterlogged. It was therefore
considered probable, by those skilled in the art, that
the original samples were extremely wet, possibly
saturated with water. On addition o~ water much better
separation was obtained. When the temperature reached a
level sufficient to cause initial boiliny of the waterr
below the local boiling point, (the later experiments
were carried out about 1.2 km a~ove sea level), it was
noted separation cease~.
In this application the term "boiling point of
water" is understood to mean the temperature at which
water and steam are in equilibrium and at which llquid
water boils internally throughout. The term "initial
boiling point of water" is understood to mean the
temp~ratur~ at which the liquid water begins to boil
internally, which is several degrees lower than the
boiling point o~ water. Both these temperatures are
~unctions of the local pressure.
DE5CRIPTION OF PREFERRED EMBODIMENTS
Tar sands were treated by variou~ microwave
generators of standard commercial type, and also u~ing a
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nonstandard ~lectromagnetic generator, in glass, pla~tic
or metal containers. In some cases the operating
microwave generator (magnetron) was replaced by another
magnetron of different ~requency.
INITIAL OBSERVATIONS
Initially, wet gloves stained with tar sand were
dried in a microwave oven of uncali~rated frequency,
10 believed to be about 950 MHz (0.95 GHz). The dried
gloves were noted to have clean sand and tar separately
adhering to them.
Bituminous tar sand in a glass container was
treated by a magnetron believed to operate at 950 MH~.
Steam was generated, after completion of treating there
was no visible water, light coloured sand on the bottom
and above it, several layers ranging from medium yellow
to very heavy black material of asphalt like appearance
on the top.
A magnetron ra~ed at 950 MHz, was connected by TV
type coaxial cable to an electronic type antenna
generator, which was introduced into a 5 gallon (20
litre) metal bucket ~ull o~ bituminous tar sand and the
magnetron switched on, the bucket and contents rapidly
became very hot. On cooling the bucket was about two
thirds full and contained three layers - a top layer of
black material resembllng partially set asphalt in
appearance and smell, below ~his a second layer of
yellowish rankish smelling mixture, below this again a
third layer of a mixture of sand, water, and other
unidentified matter. A ~ample of this third layer was
allowed to settle, the sediment appeared largely ~and
and other mineral matter and to have no apparent rust
pre~ent..
A further test wa~ performed usin~ a magnetron
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believe~ to operat~ at 1500 MHz ~amples of ~hout loo ml
of tar sand were treated, partial separation of bitumen
and sand layers was observed
A further test was performed using a ~agnetron
rated at 1250 MHz and 500 watts, partlal s paration of
bitumen and sand layers was observed.
The frequency ratings are generally believed to be
lQ accurate within about 10~.
These observations su~gest to those skilled in the
art, either that on the removal of the bitumen, that the
sand settled, grea~ly reducing the void volume of the
sand, and allowing the water present to fill the void
volume, and thus preventing the separated bitumen from
seeping back into the sand, or that there was suf~icient
water there to fill the slightly reduced void volume of
the sand on settling, that is that there was probably
more water in the initial tar sand than was usually
expected to be present. If the second possibility was
correct, these initial observations must have been
observed on tar sand containing sub~tantially more water
than normal. In effect the initial observations were
probably made on tar sand containing added-water.
EXPERIMENT~L OBSERVATIONS
A microwave generator was obtained, nominally a
950J1525 MHz L3315 magnetron, which was tested for
leakage r output in watts and ~requency of emitted
radiation. Leakage was found within tolerance. The
generator emitted radiation at frequencies measured at
920 MHz and 1540 MHz. Thers was a possible variation of
these frequencies of 10%, using this magnetron. Using a
antenna connected by cable to the ma~netron power output
was measured at about 100 watts for 920 MHz and about 80
watts for 1540 MHz, without the antenna the power was
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measured at about 0.3 watts at g20 MHz, and 3.~ watts at
1540 MHz, The microwave output Wa8 directed to the
inside of a conventional microwave oven, with the oven
ma~netron removed.
The tar sand samples used in these experiments
~except Experiment 19), were all from the same source.
It is not known whether these tar sands were the same
as~ or different from, the tar sands of the initial
observations.
The following experiments were performed at an
altitude of approximately 1.2 km at Calgary.
EXPERIMENT 1
About 15 ml of tar sand was treated for 30 minutes
at 920 MHz at 0.3 watts on a plate, no visible change
was noted, a smell of light crude lacking the typical
sulfur odour was observed.
EXPERIMENT 2
About 30 ml of tar sand was treated for 7 minutes
at 920 MHz at 100 watts in a plastic tube, the antenna
was inserted into the tar sand in the tube, the plastic
tube began to melt after 7 minutes. A water sample was
present as a check.
EXPERIMENT 3
About ~00 ml of tar sand was treated for 2.25 hour~
at 920 MHz at lQ0 watts in a glas~ container placed
upside dawn on a microwave plate, the antenna was inside
the container. The sand reached 117~F at the end of
this period, the tar sand shrank slightly, condensed
water, and clean sand grains were observed on the inside
of the container, smudges of oil yellow to light brown
in colour were noted on the inside of the container.
The observed separation was minuscule. A water sample
was present as a check~ at the end of treating it was
,~.
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EXPERIMENT 4
About 30 ml of tar sand was placed in a glass test
tube upside down over the an~enna, tin ~oil wa~ placed
on the closed end of the tube, which was treated for 2.5
hours at 920 MHz at 100 watts. A water sample waQ
present as a check. The sand settled slightly, water
vapour and droplets were observed, but no visible
separation.
EXPERIMENT 5
The magnetron-antenna cable was shortened to
increase power delivery to an estimated 160 watts at 920
MH2. About 300 ml of tar sand was treated for 3 hours
at 920 MHz at an estimated 160 watts, in an inverted
glass container on a plate, with ihe antenna inside the
container. The tar sand temperature rose to 143~F. A
water sample was present as a check, its temperature
~0 rose to the ran~e 99 to 109~F. At the end of treating,
clean sand grains and a small amount (estimated at 1 ml)
of oil and water on the inside of the container was
observed. The observed separation was minuscule.
EXPERIMENT 6
About 20Q ml of tar sand was treated for 9 hours at
920 MHz at an estimated 160 watts, in an inver~ed glass
container on a perforated plate, spaced above a second
plate r the antenna was insid~ the cont~iner. At the end
of treating, clean sand grains and a small amount of oil
and water on the inside o~ the container was observed.
A water sample was present as a check. The observed
separation was minuscule.
EXPERIMENT ~
About 200 ml of tar sand was treated for 20 minutes
at 1540 MHz at an estimated 160 watts, in an inverted
glass container on a per~orated plate, spa~ed above a
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second plate, t-he antenna was in~:ide the conta~ner. The
water check sample began to boll at the end of 20
minutes. At the end of treatiny, clean sand grains and
a small amount of water on the inside of the container
was observed. The observed separation was mlnuscule.
EXPERIMENT 8
The residual material from experiment 5, together
with added water was treated to boiling on an electric
kitchen stove in a pyrex container. Three layer
separation was observed with an oily bituminous top
layer, a water middl~ layer and a sand bottom layer.
EXPERIMENT 9
A similar sample to that of experiment 5, not
previously treated with microwave radiation at 920 MHz
was treated to boiling with added water on an electric
kitchen stove in a pyrex container. No separation was
observed.
EXPERIMENT 10
A similar sample to that of experiment 5, not
previously treated with microwave radiation, was treated
to boiling with added water by a magnetron rated at 2450
MHz. No separation was observed.
EXPERIMENT ll
About 160 ml of tar sand and 80 ml of water was
placed in a 250 ml glass container, ad~acent the
antenna, and treated on and off ~or 1 hour at 920 MHz
and 160 watts. The initial temperature was 71~F, both
water and ~and. After 5 minutes oP treating the water
was 200F, the sand 154F, an oily layer began to
separate, the oil was skimmed. Another 3 minutes
treating gave water 195F, sand 170F, with oil easily
Ploatlng to the top. 1.5 extra minutes of treating gave
water 189~F, sand 170F, with a very black oil layer
filled with gas bubbles, which was skimme~. 2 more
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minutes of treating gave water 198~F, sand 187~F, with
an oil layer over clear water and clean sand, oil
floated to the top without visible sand vlbration or
agitation, or convection currents. Another 2 ~inutes of
treatin~ gave water 194~F, sand 184F, the oil layer was
skimmed. A further 2 minutes of treating gave water
193~F, sand 181F, the oil layer was skimmed, the ~and
was ve~y clear not much tar being lePt. 2 more minute~
of treating gave water 199F (boiling), sand 192~F, the
oil layer was skimmed. About 80 to 90% of the tar was
estimated to have separated. A further four treatin~
periods each of two minutes gave water temperatures of
195, 199, 199, 19~F (boiling) and sand temperatures of
197, 201, 204, 20sF, respectively, very little
additional oil separated. It was estimated that 90 to
95~ of the tar had been removed from the sand.
EXPERIMENT 12
About 80 ml of tar sand and 160 ml of water was
placed in a 250 ml glass container, adjacent the
antenna, and treated at 1540 MH~ and 160 watts. The
initial temperature was 78F, water, and 73~F, sand.
After 2.5 minutes of treating the temperature of the
water rose to 101F and the sand to 93~F, without
separation. 3 ex-tra minute~ of treating yave water
129F, ~and 110F, without separation. A further 5
minutes of treating gave water 186~F, sand 141F, with a
very thin light o~l layer. 2 more minutes of treating
gave water 198F, sand 165~F, t~e oil layer was ~ki~med.
Another 2 minutes of treating gave water 201aF, sand
174 F. the thin oil layer waY skimmed, not much extra
separation was noted. A further series of treating
periods of 2, 1, 2, 2, 3, 2, 4.5 minutes gave water
temperatures of 203, 202, 204, 204, 204, 204, 204 F
(boiling) and sand temperatures of 176, 195, 202, 199,
201, 199, 198 F ~respectively) with very little
additional separation. It was estimated that only 20 to
25% of ~the tar had been removed from the sand.
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EXPERIMENT 13
About 80 ml of tar sand and 80 ml of water wa~
placed in a 250 ml glas~ container, adjacent the
antenna, and treate~ at 920 MHz and 160 watt~. The
initial temperature was 74F, both water and sand.
A~ter 6.5 ~inutes oF treating separatlon Wc-15 no~ed at 7
minutes, the water boiled. The temperature of the ~ater
was ls8F and the sand to 174~F, and an oil layer was
skimmed. A further 2 minutes of treating boiled the
water, water 195F, sand 188aF, lots of oil came off,
and was skimmed. An extra minute of treating boiled the
water, the experiment was discontinued.
EXPERIMENT 14
About 80 ml of tar ~and and 80 ml water was placed
in a 250 ml glass container, a distance from the
antenna, and treated at 920 MHz and 160 watts. The
initial te~perature was 74~F, both water and sand.
A~ter 7 minutes of treating separation was observed. 10
minutes gave water 144F, sand 128~F, a very thin oily
layer was noted. Further treating periods of 1, 1.5,
0.5, and 0.5 minutes boiled the water without noticeable
additional separation. The experiment was discontinued.
EXPERIMENT 15
About 80 ml of tar sand and 160 ml of water was
placed in a 250 ml glass ~ontainer, a distance from the
antenna, and treated at 920 MH~ and 160 watts. 5
minutes of treatin~ gave water 170 F, sand 131F, no
separation was noted. An extra 1 minute oP treating
gave tar gobs floatlny to the surface at water 168F,
sand 13~F. 3.5 minutes more treating gave water 183F,
sand 156F, and oil gob~ floating to the surPace. A
further 2 minutes treating gave water 199F (boiling)
and sand 169F. Another 2 minutes gave water 200 F
(boiling), sand 169~F, with heavy tar gobs floating to
the surface and sinking. About 20X of the tar separated
from the sand prior t~ boiling, no separation was
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observed after boiling.
EXPERIMENT 16
About 80 ml of tar sand and 320 ml of water was
placed in a 500 ml glass container, adjacent the
~ntenna, and treated at 920 MHz and 160 watts. After 10
minutes of treating the temperature of the water rose ~o
185~F and the sand to 151 F. Oil be~an to ~eparate.
After a further 3 minutes of treating water was 19 P F,
sand 165VF, slow separation continued. After a Purther
3 minutes oP treating the water boiled at 205~F, sand
was 179F, slow separation continued. After a further 1
minute of treatin~ the water went into rapid boil and
separation stopped. The separation was very slight.
EXPERIMENT 17
About 80 ml of tar sand and 40 ml o~ water was
placed in a 250 ml glass container, adjacent the
antenna, and treated at 920 MHz and 160 watts. After 4
minutes of treating the temperature of the water rose to
85F. A further 5 minutes o~ treating raised the water
temperature to 105F, no separation was noted. A
further 6 minutes o~ treating rai~ed the water
temperature to 125~F at which point separation was
noted, i.e. the sand and oil began to separate.
Although the oil did not rise to the surface oP the
water, clean sand gralns were observed at the bottom.
EXPERIMENT 18
About 120 ml o~ tar ~and and 40 ml water in a 250
ml glass container was treated at 920 MHz and 160 watts,
near the antenna. APter 6 minutes oP treating, no
separation was observed. After a Purther 3 minutes of
treating, water was 14~F, separation was observed. A
further 7 minutes of treating be~an to produce
noticeable ~eparation with an oil layer, water was lBl
F. The sand was beginning to compact and some tar was
trapped in the sand. A Purther 6 minut~ oP treatin~
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produced a thick clean bubbling oil at -the top, beneath
this a mixed sand oil layer (oil carryiny san~ grains),
then a water sand layer, below ~hich was clean sand.
The mixture was treated ~urther 6 minutes, the oil was
12'~, and climbing the sides o~ the container, the sand
and water was 139F, about 50 to 70% of the oil had
migrated to the top. In a further 2 minutes the water
boiled and separation stopped, the oil was 131F, ~he
sand and water was 191 F.
EXPERIMENT 19
A shaley tar sand sample was broken into chunks
forming about 5 cm cubes, and placed in about 375 ml
water, in a glass container. The container wa~ placed
adjacent the antenna, and treated at 920 MHz and 160
watts. After 2 minute~ treating, water was 121 F, the
shaley blocks started to break down to silt, with alr
bubbling out o~ the sand. 1.~ minutes more treating
produced water at 159~F, and 50% break down to silt, and
more air bubbles, some pieces floated. 2 ~urther
minutes treating produced more air bubbles, water at
l~'O~F and no separation, some water was removed. A
furthex 2 minutes treatin~ produced the beginning of
separation, clay and silt at the bo-ttom, most of the air
bubbles had gone, and an oil layer at the top, which was
skimmed. Another minute of treating produced more oil,
air bubbles originating in the silt were bringing oil
and silt to the top, and water at 1920F. A further 0.25
minutes treating boiled the water ending separation.
As those skilled in the art would realise these
preferred details can be subjected to substantial
variation, modification, change, alteration, and
substitution without affecting or modifying the function
of the especially preferred described embodiment.
Although embodiments of the invention have heen
described above, it is not limited thereto, and it will
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be apparent to persons skilled in the art that null1erou~
modifications and variation~ form part of the present
invention insofar as they do not depart ~rom the spirit,
nature and ~cope of the claimed and described invention.
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