U.S. patent application number 13/705015 was filed with the patent office on 2014-06-05 for sodium triphosphate and caustic as process aids for the extraction of bitumen from mined oil sands.
This patent application is currently assigned to Syncrude Canada Ltd. in trust for the owners of the Syncrude Project. The applicant listed for this patent is SYNCRUDE CANADA LTD. IN TRUST FOR THE OWNERS OF TH. Invention is credited to YONG GU, JUN LONG.
Application Number | 20140151270 13/705015 |
Document ID | / |
Family ID | 50824395 |
Filed Date | 2014-06-05 |
United States Patent
Application |
20140151270 |
Kind Code |
A1 |
LONG; JUN ; et al. |
June 5, 2014 |
SODIUM TRIPHOSPHATE AND CAUSTIC AS PROCESS AIDS FOR THE EXTRACTION
OF BITUMEN FROM MINED OIL SANDS
Abstract
A process of extracting bitumen from oil sand ores having a
fines content up to about 60% and a bitumen content higher than
about 6% is provided, comprising: determining a dosage (wt %) of
caustic necessary to yield a desired primary bitumen recovery;
determining an amount of caustic (wt %) and an amount of sodium
triphosphate (wt %) which yields substantially the same desired
primary bitumen recovery or greater as the dosage of caustic (wt %)
alone; mixing the oil sand ore with heated water to produce an oil
sand slurry; and adding the amounts of caustic (wt %) and sodium
triphosphate (wt %) before, during or after mixing the oil sand ore
with heated water to condition the oil sand slurry and to improve
bitumen recovery from the oil sand ore; whereby the sum of the
amounts of caustic (wt %) and sodium triphosphate (wt %) is
substantially equal to the dosage of caustic (wt %) alone.
Inventors: |
LONG; JUN; (Edmonton,
CA) ; GU; YONG; (Edmonton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SYNCRUDE CANADA LTD. IN TRUST FOR THE OWNERS OF TH |
Fort McMurray |
|
CA |
|
|
Assignee: |
Syncrude Canada Ltd. in trust for
the owners of the Syncrude Project
Fort McMurray
CA
|
Family ID: |
50824395 |
Appl. No.: |
13/705015 |
Filed: |
December 4, 2012 |
Current U.S.
Class: |
208/391 |
Current CPC
Class: |
C10G 1/047 20130101 |
Class at
Publication: |
208/391 |
International
Class: |
C10G 1/04 20060101
C10G001/04 |
Claims
1. A process of extracting bitumen from an oil sand ore having a
fines content up to about 60% and a bitumen content higher than
about 6%, comprising: determining a dosage (wt %) of caustic
necessary to yield a desired primary bitumen recovery; determining
an amount of caustic (wt %) and an amount of sodium triphosphate
(wt %) which yields substantially the same desired primary bitumen
recovery or greater as the dosage of caustic (wt %) alone; mixing
the oil sand ore with heated water to produce an oil sand slurry;
and adding the amounts of caustic (wt %) and sodium triphosphate
(wt %) before, during or after mixing the oil sand ore with heated
water to condition the oil sand slurry and to improve bitumen
recovery from the oil sand ore; whereby the sum of the amounts of
caustic (wt %) and sodium triphosphate (wt %) is substantially
equal to the dosage of caustic (wt %) alone.
2. The process of claim 1, wherein the bitumen content ranges from
about 6% to about 10%, the fines content is greater than about 25%,
the caustic amount ranges from about 0 wt % to about 0.05 wt %, and
the sodium triphosphate amount ranges from about 0.005 wt % to
about 0.05 wt %.
3. The process of claim 2, wherein the bitumen content is about 8%,
the fines content is about 40%, the caustic amount is about 0.03 wt
%, and the sodium triphosphate amount is about 0.005 wt %.
4. The process of claim 2, wherein the bitumen content is about 9%,
the fines content is about 26%, the caustic amount is about 0.03 wt
%, and the sodium triphosphate amount is about 0.05 wt %.
5. The process of claim 2, wherein the bitumen content is about
9.5%, the fines content is about 35%, the caustic amount ranges
from about 0.01 wt % to about 0.02 wt %, and the sodium
triphosphate amount ranges from about 0.005 wt % to about 0.05 wt
%.
6. The process of claim 1, wherein the bitumen content is greater
than about 10%, the fines content is less than about 20%, the
caustic amount ranges from about 0.01 wt % to about 0.05 wt %, and
the sodium triphosphate amount ranges from about 0.003 wt % to
about 0.009 wt %.
7. The process of claim 6, wherein the bitumen content is about
12%, the fines content is about 16%, the caustic amount is about
0.01 wt %, and the sodium triphosphate amount is about 0.003 wt
%.
8. The process of claim 1, wherein a total dosage of caustic and
sodium triphosphate is about 0.04 wt %, wherein the caustic amount
ranges from about 0.01 wt % to about 0.03 wt %, and the sodium
triphosphate amount ranges from about 0.01 wt % to about 0.03 wt
%.
9. The process of claim 1, wherein the caustic comprises sodium
hydroxide.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a process of extracting
bitumen from oil sand ores by adding a combination of sodium
triphosphate and caustic (sodium hydroxide) to condition the oil
sand slurry.
BACKGROUND OF THE INVENTION
[0002] Oil sand generally comprises water-wet sand grains held
together by a matrix of viscous heavy oil or bitumen. Bitumen is a
complex and viscous mixture of large or heavy hydrocarbon
molecules. The Athabasca oil sand deposits may be efficiently
extracted by surface mining which involves shovel-and-truck
operations. The mined oil sand is trucked to crushing stations for
size reduction, and fed into slurry preparation units where hot
water and caustic (sodium hydroxide) are added to form an oil sand
slurry. The oil sand slurry may be further conditioned by
transporting it using a hydrotransport pipeline to a primary
separation vessel (PSV) where the conditioned slurry is allowed to
separate under quiescent conditions for a prescribed retention
period into a top layer of bitumen froth, a middle layer of
middlings (i.e., warm water, fines, residual bitumen), and a bottom
layer of coarse tailings (i.e., warm water, coarse solids, residual
bitumen). The bitumen froth, middlings and tailings are separately
withdrawn. The bitumen froth is de-aerated, heated, and treated to
produce diluted bitumen which is further processed to produce
synthetic crude oil and other valuable commodities.
[0003] "Fines" are particles such as fine quartz and other heavy
minerals, colloidal clay or silt generally having any dimension
less than about 44 .mu.m. "Coarse solids" are solids generally
having any dimension greater than about 44 .mu.m. Oil sand
extraction typically involves processing ores which are relatively
high in bitumen content and low in fines content. However, there
exists an abundance of "poor ores" which alone yield poor bitumen
recovery and consequently cannot be processed unless a high
proportion of high-grade, good ores are blended into these dry ore
feeds. "Poor ores" are oil sand ores generally having low bitumen
content (about 6 to about 10%) and/or high fines content (greater
than about 30%). In comparison, "good ores" are oil sand ores
generally having high bitumen content (about 10 to about 12% or
higher) and/or low fines content (less than about 20%).
[0004] Caustic is used in bitumen extraction to improve bitumen
recovery and froth quality. Caustic promotes the release of natural
surfactants from bitumen to the aqueous phase, precipitates
divalent cations such as calcium and magnesium, modifies the
electrical surface potential of bitumen and solids, adjusts the pH,
and makes solids more hydrophilic, leading to better bitumen-solids
separation. For an oil sand ore, there is normally an optimal
caustic dosage at which the highest bitumen recovery can be
obtained and the optimal dosage appears to be determined by both
the fines content (Sanford, E., 1983, Can. J. Chem. Eng.
61:554-567) and the ore grade.
[0005] However, the use of caustic may create undesired
consequences. Caustic is toxic and corrosive, impacting health and
the environment and causing scaling on equipment. Compared to the
caustic dosage for good ores, a higher caustic dosage is required
for poor ores, but does not necessarily improve bitumen recovery
and froth quality. Caustic disperses fines, hindering fines
settling and tailings treatment. Higher caustic dosages induce
bitumen emulsification which impairs froth treatment.
[0006] Accordingly, there is a need for a method of minimizing the
amount of caustic used in bitumen extraction.
SUMMARY OF THE INVENTION
[0007] The current application is directed to a process of
extracting bitumen from mined oil sand ores by adding a combination
of sodium triphosphate and caustic to condition the oil sand
slurry. It was surprisingly discovered that by conducting the
process of the present invention, one or more of the following
benefits may be realized:
[0008] (1) The combined use of sodium triphosphate and caustic has
a synergistic effect, improving bitumen recovery and froth quality
in poor (low-grade high-fines) and good ores.
[0009] (2) For good ores, the combined use of sodium triphosphate
and caustic does not have any negative impact on
processability.
[0010] (3) The combined use of sodium triphosphate and caustic
requires a lower amount of total chemical addition than the use of
caustic alone, and is more effective at much lower dosages than
caustic alone.
[0011] (4) The combined use of sodium triphosphate and caustic
minimizes the amount of caustic, negating problems normally
encountered by use of high caustic dosages. Sodium triphosphate is
non-toxic to humans, animals, and the environment; a scaling and
corrosion inhibitor; reduces the chances of bitumen emulsification;
and hydrolyzes such that divalent cations captured in chelating
form may be released for fine solids coagulation in tailings
treatment; and the hydrolyzed species (e.g., ATP which is
nutritious and essential to life) may positively impact the
environment and land reclamation.
[0012] Thus, use of the present invention conserves the amounts of
process aids in bitumen extraction, and improves bitumen recovery
and froth quality.
[0013] In one aspect, a process of extracting bitumen from oil sand
ores having a fines content up to about 60% and a bitumen content
higher than about 6% is provided, comprising: [0014] determining a
dosage (wt %) of caustic necessary to yield a desired primary
bitumen recovery; [0015] determining an amount of caustic (wt %)
and an amount of sodium triphosphate (wt %) which yields
substantially the same desired primary bitumen recovery or greater
as the dosage of caustic (wt %) alone; [0016] mixing the oil sand
ore with heated water to produce an oil sand slurry; and [0017]
adding the amounts of caustic (wt %) and sodium triphosphate (wt %)
before, during or after mixing the oil sand ore with heated water
to condition the oil sand slurry and to improve bitumen recovery
from the oil sand ore; [0018] whereby the sum of the amounts of
caustic (wt %) and sodium triphosphate (wt %) is substantially
equal to the dosage of caustic (wt %).
[0019] In one embodiment, the amount of caustic ranges from about 0
wt % to about 0.05 wt % of poor oil sand ore. In one embodiment,
the sufficient amount of sodium triphosphate ranges from about
0.005 wt % to about 0.05 wt % of poor oil sand ore.
[0020] In one embodiment, the amount of caustic ranges from about 0
wt % to about 0.05 wt % of good oil sand ore. In one embodiment,
the amount of sodium triphosphate ranges from about 0.003 wt % to
about 0.009 wt % of good oil sand ore.
[0021] In one embodiment, the caustic is sodium hydroxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Referring to the drawings wherein like reference numerals
indicate similar parts throughout the several views, several
aspects of the present invention are illustrated by way of example,
and not by way of limitation, in detail in the figures,
wherein:
[0023] FIG. 1 is a schematic showing, in general, the extraction
process for extracting bitumen from mined oil sand ore.
[0024] FIG. 2 is a graph showing primary bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for poor oil sand AR.
[0025] FIG. 3 is a graph showing primary froth bitumen content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AR.
[0026] FIG. 4 is a graph showing primary froth solids content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AR.
[0027] FIG. 5 is a graph showing combined bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for poor oil sand AR.
[0028] FIG. 6 is a graph showing primary bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for poor oil sand AD.
[0029] FIG. 7 is a graph showing primary froth bitumen content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AD.
[0030] FIG. 8 is a graph showing primary froth solids content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AD.
[0031] FIG. 9 is a graph showing combined bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for poor oil sand AD.
[0032] FIG. 10 is a graph showing combined froth bitumen content
(%) as a function of dosages (wt %) of caustic or sodium
triphosphate alone, or in combination, for poor oil sand AD.
[0033] FIG. 11 is a graph showing primary bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for poor oil sand AAX.
[0034] FIG. 12 is a graph showing primary froth bitumen content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AAX.
[0035] FIG. 13 is a graph showing primary froth solids content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AAX.
[0036] FIG. 14 is a graph showing combined bitumen recovery (%) as
a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for poor oil sand AAX.
[0037] FIG. 15 is a graph showing primary bitumen recovery (%) as a
function of dosages (wt %) of caustic or sodium triphosphate alone,
or in combination, for good ore AR12.
[0038] FIG. 16 is a graph showing primary froth bitumen content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for good ore AR12.
[0039] FIG. 17 is a graph showing primary froth solids content (%)
as a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for good ore AR12.
[0040] FIG. 18 is a graph showing combined bitumen recovery (%) as
a function of dosages (wt %) of caustic or sodium triphosphate
alone, or in combination, for good ore AR12.
[0041] FIG. 19 is a graph showing combined froth bitumen content
(%) as a function of dosages (wt %) of caustic or sodium
triphosphate alone, or in combination, for good ore AR12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The detailed description set forth below in connection with
the appended drawings is intended as a description of various
embodiments of the present invention and is not intended to
represent the only embodiments contemplated by the inventor. The
detailed description includes specific details for the purpose of
providing a comprehensive understanding of the present invention.
However, it will be apparent to those skilled in the art that the
present invention may be practiced without these specific
details.
[0043] The present invention relates generally to a process of
extracting bitumen from mined oil sand ores by adding a combination
of sodium triphosphate and caustic to condition the oil sand
slurry.
[0044] In one embodiment of the process of the present invention
useful in extracting bitumen from oil sand ores, oil sand is mined
from an oil sand rich area such as the Athabasca Region of Alberta.
The oil sand ore may comprise a fines content up to about 60% and a
bitumen content greater than about 6%.
[0045] FIG. 1 is a general schematic of a bitumen extraction
process from mined oil sand ore. The oil sand is mixed with heated
water in a slurry preparation unit. The slurry preparation unit may
comprise a tumbler, screening device and pump box; however, it is
understood that any slurry preparation unit known in the art can be
used.
[0046] In addition to the oil sand and water, sodium triphosphate
and caustic are also added to the slurry preparation unit to aid in
conditioning the oil sand slurry. As used herein, the term "sodium
triphosphate" means the sodium salt of the polyphosphate
penta-anion which is the conjugate base of triphosphoric acid.
Synonyms, abbreviations, and other names for sodium triphosphate
include STP, STPP, sodium tripolyphosphate, and TPP. Sodium
triphosphate has the molecular formula Na.sub.5P.sub.3O.sub.10.
Triphosphate is a chelating agent which binds strongly to metal
cations such as, for example, calcium and magnesium. Since
polyphosphates are hydrolyzed into simpler phosphates,
polyphosphates are non-toxic to humans, animals, and the
environment.
[0047] The amount of caustic is determined by initially testing
varying caustic dosages to elucidate the optimal caustic dosage
which yields a desired primary bitumen recovery. In one embodiment,
the sufficient amount of caustic ranges from about 0.01 wt % to
about 0.05 wt % of poor oil sand ore. In one embodiment, the
sufficient amount of caustic ranges from about 0.01 wt % to about
0.05 wt % of good oil sand ore. In one embodiment, the caustic is
sodium hydroxide.
[0048] The amount of sodium triphosphate is determined by the
optimal caustic dosage and type of oil sand ore. In one embodiment,
the dosage for each of caustic and sodium triphosphate does not
exceed 0.05 wt % since higher dosages are impractical in industrial
operations due to costs and efforts to conserve process aids. In
one embodiment, the sufficient amount of sodium triphosphate ranges
from about 0.005 wt % to about 0.05 wt % of poor oil sand ore. In
one embodiment, the sufficient amount of sodium triphosphate ranges
from about 0.003 wt % to about 0.009 wt % of good oil sand ore.
[0049] The sodium triphosphate and caustic may be added to the
water prior to mixing with oil sand, directly into the slurry
preparation unit during mixing, or to the oil sand slurry prepared
prior to hydrotransport/slurry conditioning. Preferably, the sodium
triphosphate and caustic are added to the heated water.
[0050] Following the addition of sodium triphosphate and caustic,
the oil sand slurry may be screened through a screen portion, where
additional water may be added to clean the rejects (e.g., oversized
rocks) prior to delivering the rejects to a rejects pile. The
screened oil sand slurry is collected in a vessel such as pump box
where the oil sand slurry is then pumped through a hydrotransport
pipeline (slurry conditioning), which pipeline is of a adequate
length to ensure sufficient conditioning of the oil sand slurry,
e.g., thorough digestion/ablation/dispersion of the larger oil sand
lumps, coalescence of released bitumen flecks and aeration of the
coalesced bitumen droplets.
[0051] The conditioned oil sand slurry is then fed to a bitumen
separation vessel (also referred to as a primary separation vessel
or PSV), which bitumen separation vessel operates under somewhat
more quiescent conditions to allow the bitumen droplets to rise to
the top of the vessel and form bitumen froth, which froth over
flows to the launder and is collected for further froth treatment.
Tailings are either discarded or further treated for additional
bitumen recovery.
[0052] Exemplary embodiments of the present invention are described
in the following Example, which is set forth to aid in the
understanding of the invention, and should not be construed to
limit in any way the scope of the invention as defined in the
claims which follow thereafter.
Example 1
[0053] Samples of three poor ores and one good ore were tested
(Table 1). The three poor ores had bitumen contents ranging from
8.7% to 9.6%, with fines contents from 26% up to 39%. The good ore
had a bitumen content of 11.9% and a fines content of 16%.
TABLE-US-00001 TABLE 1 Classification of Ore Poor Ore Good Ore
Designation AR AAX AD AR12 Bitumen, % 9.0 8.7 9.6 11.9 Solids <
44 .mu.m, % 26 39 38 16 Solids d.sub.50, .mu.m 213 92 80 130
[0054] Batch extraction unit testing was conducted, using blended
process water, conducting conditioning at 50.degree. C., and
testing different dosages of caustic alone, sodium triphosphate
alone, and a combination of caustic and sodium triphosphate to
assess whether a combination of process aids might have a
synergistic effect. The dosages were based upon the dry oil sand
weight (500 g for each test). Initial tests involving addition of
caustic alone were conducted to find an optimal caustic dosage for
each ore, followed by subsequent tests involving addition of sodium
triphosphate alone, and in combination with caustic. The dosages
for caustic or sodium triphosphate did not exceed 0.05 wt % since
higher dosages are impractical in plant operations due to costs and
efforts to conserve process aids.
[0055] The data were reconciled for material balance using the
Bilmat.TM. program, Version 9.2, 2006 (Algosys Inc., Quebec, CA).
The extraction performance was indicated by the primary, secondary,
and wall bitumen recoveries (R.sub.p, R.sub.s, R.sub.w), which were
calculated using equation (1):
R i = M if X B , if M os X B , os ( 1 ) ##EQU00001##
where R denotes bitumen recovery; M is the mass; X is the mass
fraction; the subscript i represents either primary (p), secondary
(s), or wall (w); and the subscripts f, B, and os stand for froth,
bitumen, and oil sand, respectively.
[0056] The combined recovery (R.sub.c) which is the sum of the
primary and secondary recoveries was calculated using equation
(2):
R.sub.c=R.sub.p+R.sub.s (2)
[0057] The total recovery (R.sub.t) which is the sum of the
primary, secondary, and wall bitumen recoveries was calculated
using equation (3):
R.sub.t=R.sub.p+R.sub.s+R.sub.w (3)
Poor Ore AR
[0058] For poor ore AR, the primary bitumen recovery was 11.6% when
no process aid was used (Table 2). The addition of caustic improved
processability. As the primary bitumen recovery did not
substantially change when the caustic dosage was increased from
0.03% to 0.04%, 0.03% was selected as the dosage for further
testing with sodium triphosphate addition. When the caustic dosage
was further increased to 0.05%, the primary bitumen recovery
increased to 32.2%.
[0059] The primary bitumen recovery and primary froth bitumen
content generally increased with increasing chemical dosage (FIGS.
2 and 3). The results for caustic alone and sodium triphosphate
alone were almost identical for primary bitumen recovery (FIG. 2)
and primary froth bitumen content (FIG. 3), indicating that sodium
triphosphate was as effective as caustic. The combined use of
caustic and sodium triphosphate is preferred due to having a
synergistic effect. The best performance was achieved with the
combination of reagents (caustic at 0.03 wt % and sodium
triphosphate at 0.05 wt %) which yielded a primary bitumen recovery
of 53.3% and a primary froth bitumen content of 44.6%.
TABLE-US-00002 TABLE 2 Chemical Bitumen Recovery, % Froth Quality
Test Dosage, wt % Wall Bitumen Content, % Solids Content, % Series
Caustic STP Primary Secondary Froth Combined Total Primary
Secondary Combined Primary Secondary Combined 1 0 0 11.6 10.4 1.1
21.9 23.0 21.7 15.7 18.4 6.9 30.1 19.7 0.01 0 13.8 15.0 2.2 28.8
31.0 24.8 18.6 21.2 8.5 32.6 23.0 0.02 0 15.5 14.8 2.0 30.3 32.3
25.9 17.6 21.2 8.5 31.4 22.1 0.03 0 21.0 17.7 2.1 38.7 40.8 28.9
19.8 23.9 9.0 29.6 20.5 0.04 0 20.2 17.1 2.7 37.3 40.0 29.4 21.7
25.3 9.3 31.4 21.2 0.05 0 32.2 18.6 3.1 50.8 53.9 31.1 22.9 27.5
10.4 28.9 18.5 2 0 0.01 13.9 9.2 0.7 23.0 23.7 21.0 10.4 15.0 7.3
18.4 13.6 0 0.02 16.3 8.7 0.5 25.0 25.5 25.9 9.8 16.5 7.0 17.4 13.1
0 0.03 20.5 9.6 0.4 30.1 30.5 29.3 11.6 19.7 6.8 20.9 14.4 0 0.04
26.8 13.6 0.7 40.4 41.1 32.5 12.4 21.1 7.8 19.9 14.7 0 0.05 27.7
15.4 0.8 43.1 44.0 33.1 18.0 25.5 8.3 24.8 16.6 3 0.01 0.01 18.5
8.8 0.5 27.2 27.7 28.6 15.9 22.7 5.6 29.6 16.7 0.01 0.02 20.3 12.3
0.6 32.6 33.2 30.8 15.6 22.6 5.9 27.0 17.3 0.01 0.03 25.6 18.8 0.8
44.3 45.2 35.9 19.9 26.8 6.8 29.5 19.8 0.01 0.04 30.5 17.9 0.8 48.4
49.2 38.6 22.0 30.2 9.9 27.9 19.0 0.01 0.05 29.6 20.7 1.0 50.3 51.3
36.8 23.3 29.7 7.9 29.2 19.1 4 0.03 0.01 28.5 17.4 0.9 45.8 46.8
37.0 20.1 28.0 7.2 29.9 19.2 0.03 0.02 29.9 16.7 0.8 46.6 47.4 37.4
21.0 29.2 9.7 26.7 18.2 0.03 0.03 32.6 20.0 0.9 52.6 53.6 38.8 24.3
31.6 9.2 28.8 18.9 0.03 0.04 42.7 26.0 1.1 68.7 69.8 42.5 27.9 35.5
10.5 29.0 19.4 0.03 0.05 53.3 20.5 1.1 73.7 74.9 44.6 28.3 38.5
12.6 28.4 18.5
[0060] For the primary froth solids content, sodium triphosphate
alone or in combination with caustic (0.01 wt %) resulted in lower
froth solids contents than the use of caustic alone (FIG. 4). When
caustic (0.03 wt %) was combined with different dosages of sodium
triphosphate (0.01-0.05 wt %), the froth solids contents were
similar to those obtained with the use of caustic alone.
[0061] For a fair comparison, the total chemical dosage (caustic
and sodium triphosphate dosages) should be considered. When sodium
triphosphate (0.01 wt %) and caustic (0.03 wt %) were combined, the
total chemical dosage was 0.04 wt %. Compared to caustic alone
(0.04 wt %), the primary recovery increased from 20.2% to 28.5% and
primary froth bitumen content increased from 29.4% to 37% (Table
3). The results of primary bitumen recovery and primary froth
bitumen content were grouped by the total chemical dosages for oil
sand AR. For every group at the same total chemical dosage, the
combined use of caustic and sodium triphosphate improved the
primary froth quality. The primary bitumen recovery was also
improved by the combined uses of caustic and sodium triphosphate,
except for the case with a total chemical dosage of 0.03 wt %, at
which the primary recoveries did not differ.
TABLE-US-00003 TABLE 3 Chemical Dosage, wt % Primary Froth Bitumen
Group Total Caustic STP Recovery, % Content, % 1 0.02 0.02 0 15.5
25.9 0.02 0 0.02 16.3 25.9 0.02 0.01 0.01 18.5 28.6 2 0.03 0.03 0
21.0 28.9 0.03 0 0.03 20.5 29.3 0.03 0.01 0.02 20.3 30.8 3 0.04
0.04 0 20.2 29.4 0.04 0 0.04 26.8 32.5 0.04 0.01 0.03 25.6 35.9
0.04 0.03 0.01 28.5 37.0 4 0.05 0.05 0 32.2 31.1 0.05 0 0.05 27.7
33.1 0.05 0.01 0.04 30.5 38.6 0.05 0.03 0.02 29.9 37.4
Similar to the primary bitumen recovery (FIG. 2), the combined
bitumen recovery (sum of the primary plus secondary recoveries;
FIG. 5) was also improved by the combination of caustic (0.03 wt %)
and sodium triphosphate at various dosages.
Poor Ore AD
[0062] Poor ore AD processed reasonably well with a primary
recovery of 70.2% and a total recovery of 87.7% when no process aid
was used (Table 4). The caustic dosage of 0.02 wt % was selected
based on the raw primary froth amounts obtained from test series
#1. Based upon the total bitumen recoveries, it appears that 0.01
wt % should be the optimal caustic dosage; thus, the caustic dosage
of 0.02 wt % used in test series #3 was higher than the optimal
dosage.
[0063] Sodium triphosphate performed much better than caustic in
regards to primary bitumen recovery (FIG. 6) and primary froth
quality (FIG. 7). The lowest primary bitumen recovery was 82.9%
(sodium triphosphate, 0.005 wt %) which was still higher than the
highest primary bitumen recovery of 78.9% obtained with caustic
(0.04 wt %). For caustic, the primary froth bitumen content was
about 50% and did not generally change with increasing caustic
dosage. In contrast, the primary froth bitumen content was higher
than 60% with sodium triphosphate. The highest primary froth
bitumen content was 68.2% with sodium triphosphate at 0.02 wt %.
Sodium triphosphate also reduced the primary froth solids content
when compared to caustic (FIG. 8). Sodium triphosphate performed
significantly better than caustic, significantly increasing the
primary bitumen recovery and the froth bitumen content, and
reducing the froth solids content. The overall performance using
sodium triphosphate at 0.005 wt % was superior than using caustic
at 0.05 wt %.
[0064] For the combination of caustic and sodium triphosphate, the
performance was generally better than caustic. Significant
increases were observed for the primary bitumen recovery (FIG. 6)
and the primary froth bitumen content (FIG. 7). For the primary
froth solids content, the results of the combination of caustic and
sodium triphosphate were similar to those of caustic (FIG. 8).
TABLE-US-00004 TABLE 4 Chemical Bitumen Recovery, % Froth Quality
Test Dosage, wt % Wall Bitumen Content, % Solids Content, % Series
Caustic STP Primary Secondary Froth Combined Total Primary
Secondary Combined Primary Secondary Combined 1 0 0 70.2 15.9 1.6
86.1 87.7 50.3 11.6 42.1 8.2 24.4 19.2 0.01 0 73.6 17.9 1.6 91.5
93.2 50.0 13.6 40.2 9.2 22.3 21.5 0.02 0 70.1 18.2 1.9 88.3 90.3
48.6 11.9 41.7 9.2 26.8 17.7 0.03 0 72.6 16.7 2.1 89.3 91.4 48.1
12.3 41.9 9.8 27.0 18.4 0.04 0 78.9 11.9 1.8 90.8 92.7 48.7 12.2
44.0 10.6 26.7 18.0 0.05 0 78.6 12.1 2.2 90.7 92.9 48.6 11.4 46.0
9.7 34.1 18.9 2 0 0.005 82.9 6.8 2.0 89.7 91.8 62.3 12.2 54.9 8.3
22.6 29.2 0 0.01 86.1 6.3 1.8 92.4 94.2 60.1 10.9 54.1 8.1 22.9
25.5 0 0.02 84.5 6.4 1.1 90.9 92.1 68.2 10.9 58.7 8.2 20.7 21.4 0
0.03 85.5 5.6 1.2 91.1 92.3 62.7 12.4 57.3 10.5 24.8 24.0 0 0.05
83.9 6.9 1.1 90.8 91.9 63.5 10.9 57.7 8.7 27.2 22.3 3 0.02 0.005
80.8 9.5 1.7 90.2 91.9 50.6 10.6 46.4 8.5 27.3 20.2 0.02 0.01 77.9
5.7 1.2 83.6 84.8 53.0 10.6 49.0 8.8 24.0 21.3 0.02 0.02 87.1 4.5
1.0 91.6 92.6 68.5 11.7 61.1 9.7 19.9 23.0 0.02 0.03 85.9 6.1 1.2
91.9 93.2 58.6 12.3 52.1 10.0 20.3 23.6 0.02 0.05 88.9 2.7 1.0 91.6
92.6 68.8 10.9 64.9 10.1 22.6 19.4
[0065] FIG. 9 shows the results of the combined bitumen recovery.
The results of all three test series were similar (about 90%) and
did not appear to change with the chemical dosages. However, sodium
triphosphate alone and in combination with caustic significantly
improved the combined froth quality by increasing the combined
froth bitumen content compared to caustic alone (FIG. 10).
[0066] The results of primary bitumen recovery and froth bitumen
content for poor ore AD were grouped by the total chemical dosage
(Table 5). For every group at the same total chemical dosage,
sodium triphosphate alone or in combination with caustic
outperformed caustic alone.
TABLE-US-00005 TABLE 5 Chemical Dosage, wt % Primary Froth Bitumen
Group Total Caustic STP Recovery, % Content, % 1 0.01 0.01 0 73.6
40.2 0.005 0 0.005 82.9 54.9 0.01 0 0.01 86.1 54.1 2 0.02 0.02 0
70.1 41.7 0.02 0 0.02 84.5 58.7 3 0.03 0.03 0 72.6 41.9 0.03 0 0.03
85.5 57.3 0.025 0.02 0.005 80.8 46.4 0.03 0.02 0.01 77.9 49.0 4
0.04 0.04 0 78.9 44.0 0.04 0.02 0.02 87.1 61.1 5 0.05 0.05 0 78.6
46.0 0.05 0 0.05 83.9 57.7 0.05 0.02 0.03 85.9 52.1
Poor Ore AAX
[0067] Ore AAX was a very poor processing ore. The primary bitumen
recovery was low at 13.0% coupled with a low primary froth bitumen
content at 19.7% when no process aid was used (Table 6). Even at
the highest caustic dosage (0.05 wt %), the primary recovery
remained low at 26.7%, and did not appear to change with the
increased caustic dosage from 0.02 wt % to 0.04 wt %. The dosage of
0.03 wt % was thus not necessarily the optimal dosage.
TABLE-US-00006 TABLE 6 Chemical Bitumen Recovery, % Froth Quality
Test Dosage, wt % Wall Bitumen Content, % Solids Content, % Series
Caustic STP Primary Secondary Froth Combined Total Primary
Secondary Combined Primary Secondary Combined 1 0 0 13.0 8.6 0.6
21.6 22.2 19.7 11.6 15.5 7.8 16.2 12.2 0.01 0 16.9 11.0 0.7 27.9
28.6 26.0 11.1 17.0 8.6 15.2 12.6 0.02 0 21.6 11.2 0.7 32.8 33.5
32.1 13.3 21.7 8.1 15.3 12.1 0.03 0 23.0 12.9 0.8 35.9 36.7 28.4
12.4 19.3 7.5 13.5 10.8 0.04 0 22.9 15.4 1.0 38.3 39.3 29.4 13.9
20.3 7.8 14.9 12.0 0.05 0 26.7 16.2 1.1 42.9 44.0 34.8 15.7 23.8
7.0 14.8 11.5 2 0 0.005 20.7 10.4 0.4 31.1 31.5 29.2 13.3 20.9 6.9
17.7 12.6 0 0.01 26.4 10.7 0.6 37.1 37.7 32.9 11.2 21.1 7.0 16.6
12.2 0 0.02 36.7 13.4 0.6 50.1 50.7 41.0 13.3 26.4 6.5 18.4 12.8 0
0.03 37.8 14.9 0.6 52.6 53.3 41.7 13.8 26.5 6.3 13.9 10.4 0 0.05
41.6 14.9 0.9 56.5 57.3 42.0 17.3 30.5 8.4 14.6 11.2 3 0.03 0.005
57.7 16.1 3.1 73.8 76.9 51.9 20.1 38.6 7.9 15.6 11.1 0.03 0.01 46.5
17.9 1.0 64.4 65.4 39.0 15.7 27.6 8.2 16.0 12.0 0.03 0.02 50.6 17.7
1.2 68.3 69.4 41.0 18.9 31.5 7.1 14.0 10.1 0.03 0.03 54.2 15.7 2.5
69.9 72.4 47.0 20.0 36.1 8.1 16.0 11.3 0.03 0.05 59.5 16.1 1.4 75.6
77.0 49.6 20.7 38.3 9.4 18.8 13.1
[0068] Sodium triphosphate outperformed caustic, increasing the
primary bitumen recovery (FIG. 11) and froth bitumen content (FIG.
12), and decreasing the froth solids content (FIG. 13). The best
performance for caustic was obtained at the highest dosage of 0.05
wt %. A similar performance was achieved at a sodium triphosphate
dosage as low as 0.01 wt %. The combined use of caustic and sodium
triphosphate had a synergistic effect, yielding greater increases
in the primary bitumen recovery (FIG. 11) and the primary froth
bitumen content (FIG. 12) compared to either caustic or sodium
triphosphate. The best performance was achieved with the
combination of reagents (the lowest sodium triphosphate dosage at
0.005 wt % and caustic at 0.03 wt %) which yielded a primary
bitumen recovery of 57.7% and a primary froth bitumen content of
51.9%. For the primary froth solids content, the results of the
combination of caustic and sodium triphosphate were similar to
those of caustic (FIG. 13). Sodium triphosphate alone or in
combination with caustic improved the combined bitumen recovery
when compared to caustic (FIG. 14). The trends for the combined
bitumen recovery are similar to those for the primary bitumen
recovery (FIG. 11).
[0069] The results of the primary bitumen recovery and the primary
froth bitumen content for poor ore AAX were grouped by the total
chemical dosage (Table 7). For every group at the same total
chemical dosage, sodium triphosphate alone or in combination with
caustic (0.03 wt %) performed significantly better than
caustic.
TABLE-US-00007 TABLE 7 Chemical Dosage, wt % Primary Froth Bitumen
Group Total Caustic STP Recovery, % Content, % 1 0.01 0.01 0 16.9
26.0 0.005 0 0.005 20.7 29.2 0.01 0 0.01 26.4 32.9 2 0.02 0.02 0
21.6 32.1 0.02 0 0.02 36.7 41.0 3 0.03 0.03 0 23.0 28.4 0.03 0 0.03
37.8 41.7 4 0.04 0.04 0 22.9 29.4 0.04 0.03 0.01 46.5 39.0 0.035
0.03 0.005 57.7 51.9 5 0.04 0.04 0 22.9 29.4 0.04 0.03 0.01 46.5
39.0 0.035 0.03 0.005 57.7 51.9
Good Ore AR12
[0070] Testing of a good ore was conducted to confirm whether any
of the process aids might have negative effects on the
processability. Ore AR12 was a good processing ore, yielding a
total recovery of 97.5% when no process aid was used (Table 8).
Caustic and sodium triphosphate, alone or in combination, had
little effect on the total bitumen recovery, but improved the
primary bitumen recovery and froth quality.
[0071] The primary bitumen recovery was about 88% when no process
aid was used (FIG. 15). When caustic (0.01 wt %) was used, the
primary bitumen recovery increased to 92.5% and did not appear to
change as the dosage increased. With sodium triphosphate (0.006 wt
%), the primary bitumen recovery reached 92.8%. The combination of
caustic (0.01 wt %) and sodium triphosphate (0.003 wt %) yielded a
primary bitumen recovery of 94.0%.
[0072] Without any process aid, the primary froth bitumen content
was 52.9% (FIG. 16). The primary froth bitumen content increased
with increasing caustic dosage, reaching 61.7% at the highest
caustic dosage (0.03 wt %). With sodium triphosphate (0.006 wt %),
the bitumen content was 57.9%. The combined use of caustic and
sodium triphosphate had a synergistic effect, with the primary
froth bitumen content sharply increasing as the sodium triphosphate
dosage increased. With sodium triphosphate (0.009 wt %) and caustic
(0.01 wt %), the primary froth bitumen content reached 64.6%. For
the primary froth solids content (FIG. 17), there were no
noticeable differences among the various process aids.
[0073] The effects of sodium triphosphate alone and in combination
with caustic on combined bitumen recovery are shown in FIG. 18. The
results did not appear to change with increased dosage and were
within the experimental error range. However, the combined froth
bitumen quality was significantly improved by the combined use of
caustic and sodium triphosphate (FIG. 19) as was the case for the
primary froth bitumen content (FIG. 16). Overall, the results
indicate that use of sodium triphosphate alone and in combination
with caustic did not have any negative impacts on the
processability of the good ore.
TABLE-US-00008 TABLE 8 Chemical Bitumen Recovery, % Froth Quality
Test Dosage, wt % Wall Bitumen Content, % Solids Content, % Series
Caustic STP Primary Secondary Froth Combined Total Primary
Secondary Combined Primary Secondary Combined 1 0 0 88.0 7.7 1.7
95.8 97.5 52.9 29.6 49.8 12.3 22.2 13.6 0.01 0 92.5 3.4 2.1 95.9
98.0 55.7 28.3 53.9 12.8 24.7 13.6 0.02 0 91.9 3.2 2.4 95.1 97.5
59.3 34.1 57.9 12.8 23.1 13.4 0.03 0 92.2 3.3 2.2 95.5 97.8 61.7
31.5 59.7 13.1 18.8 13.4 2 0 0.003 91.1 4.7 2.1 95.7 97.8 53.9 28.9
51.8 13.1 23.5 14.0 0 0.006 92.8 3.1 2.0 95.9 97.9 57.9 27.2 55.8
13.9 28.3 14.9 0 0.009 93.1 2.7 1.9 95.9 97.7 57.5 25.4 55.5 14.1
29.1 15.1 3 0.01 0.003 94.0 1.8 1.9 95.8 97.7 58.1 28.9 57.1 13.6
27.4 14.1 0.01 0.006 94.4 2.0 1.4 96.5 97.9 61.8 25.5 60.0 13.7
25.1 14.2 0.01 0.009 93.6 1.8 1.4 95.4 96.8 64.6 30.1 63.2 13.1
22.0 13.4
[0074] From the foregoing description, one skilled in the art can
easily ascertain the essential characteristics of this invention,
and without departing from the spirit and scope thereof, can make
various changes and modifications of the invention to adapt it to
various usages and conditions. Thus, the present invention is not
intended to be limited to the embodiments shown herein, but is to
be accorded the full scope consistent with the claims, wherein
reference to an element in the singular, such as by use of the
article "a" or "an" is not intended to mean "one and only one"
unless specifically so stated, but rather "one or more". All
structural and functional equivalents to the elements of the
various embodiments described throughout the disclosure that are
known or later come to be known to those of ordinary skill in the
art are intended to be encompassed by the elements of the claims.
Moreover, nothing disclosed herein is intended to be dedicated to
the public regardless of whether such disclosure is explicitly
recited in the claims.
* * * * *