U.S. patent application number 14/928541 was filed with the patent office on 2016-05-05 for mining and processing system for oil sand ore bodies.
The applicant listed for this patent is SYNCRUDE CANADA LTD. in trust for the owners of the Syncrude Project, as such owners exist now and. Invention is credited to MICHAEL CARNIATO, RON CLEMINSON, DAN WOLFE.
Application Number | 20160122657 14/928541 |
Document ID | / |
Family ID | 55809356 |
Filed Date | 2016-05-05 |
United States Patent
Application |
20160122657 |
Kind Code |
A1 |
CLEMINSON; RON ; et
al. |
May 5, 2016 |
MINING AND PROCESSING SYSTEM FOR OIL SAND ORE BODIES
Abstract
A process line for use in an oil sands ore body mining operation
is provided, which comprises: a semi-mobile crushing station for
receiving as-mined oil sand ore and comminuting the oil sand ore to
a first size; a semi-mobile compact slurry preparation unit for
receiving the comminuted oil sand ore and mixing the oil sand ore
with water to form an oil sand slurry; and a semi-mobile solids
removal assembly for removing a portion of the coarse solids from
the oil sand slurry prior to extracting from the slurry an enriched
bitumen froth.
Inventors: |
CLEMINSON; RON; (Fort
McMurray, CA) ; WOLFE; DAN; (Edmonton, CA) ;
CARNIATO; MICHAEL; (Calgary, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SYNCRUDE CANADA LTD. in trust for the owners of the Syncrude
Project, as such owners exist now and |
Fort McMurray |
|
CA |
|
|
Family ID: |
55809356 |
Appl. No.: |
14/928541 |
Filed: |
October 30, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62073576 |
Oct 31, 2014 |
|
|
|
Current U.S.
Class: |
208/391 |
Current CPC
Class: |
C10G 1/045 20130101;
C10G 1/047 20130101 |
International
Class: |
C10G 1/04 20060101
C10G001/04 |
Claims
1. A process line for use in an oil sand ore body mining operation,
comprising: a semi-mobile crushing station for receiving as-mined
oil sand ore and comminuting the oil sand ore to a first size; a
semi-mobile compact slurry preparation unit for receiving the
comminuted oil sand ore and mixing the oil sand ore with water to
form an oil sand slurry; and a semi-mobile solids removal assembly
for removing a portion of the coarse solids from the oil sand
slurry prior to extracting from the slurry an enriched bitumen
froth.
2. The process line as claimed in claim 1, wherein the semi-mobile
crushing station is relocatable in about two weeks.
3. The process line as claimed in claim 1, wherein the semi-mobile
crushing station is relocated about every year.
4. The process line as claimed in claim 1, wherein the semi-mobile
crushing station comprises an integral rock crusher and discharge
conveyor.
5. The process line as claimed in claim 1, wherein as-mined oil
sand ore is delivered to the semi-mobile crushing station by means
of mobile trucks.
6. The process line as claimed in claim 1, wherein more than one
semi-mobile crushing station is used in an oil sand mine.
7. The process line as claimed in claim 1, wherein the semi-mobile
solids removal assembly comprises a semi-mobile desanding
assembly.
8. The process line as claimed in claim 1, wherein the semi-mobile
solids removal assembly comprises a semi-mobile screening
assembly.
9. The process line as claimed in claim 1, wherein the semi-mobile
solids removal assembly comprises a semi-mobile screening assembly
and a semi-mobile desanding assembly.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to mining technology and a
process line for increasing the efficiency of an ore mining
operation.
BACKGROUND OF THE INVENTION
[0002] Oil sand ore, such as is mined in the Fort McMurray region
of Alberta, generally comprises water-wet sand grains held together
by a matrix of viscous bitumen. Typically, a "low grade" oil sand
ore will contain between about 6 to 10 wt.% bitumen with about 25
to 35 wt. % fines. An "average grade" oil sand ore will typically
contain at least 10 wt. % bitumen to about 12.5 wt. % bitumen with
about 15 to 25 wt. % fines and a "high grade" oil sand ore will
typically contain greater than 12.5 wt. % bitumen with less than 15
wt. % fines. "Fines" are generally defined as those solids having a
size less about 44 .mu.m.
[0003] Oil sand lends itself to liberation of the sand grains from
the bitumen, preferably by slurrying the oil sand with heated
water, allowing the bitumen to move to the aqueous phase. For many
years, the bitumen in the McMurray sand has been commercially
removed from oil sand using what is commonly referred to in the
industry as the "hot water process". In general terms, the hot
water process involves dry mining the oil sand at a mine site that
can be kilometers from an extraction plant; transporting the
as-mined oil sand in large ore trucks to a primary crushing plant;
conveying the crushed ore to a slurry preparation plant where the
oil sand is mixed with hot water, caustic (e.g., sodium hydroxide)
and naturally entrained air to yield an oil sand slurry;
"conditioning" the oil sand slurry (for example, in a
hydrotransport pipeline) so that lumps of oil sand are ablated or
disintegrated, the released sand grains and separated bitumen
flecks are dispersed in the water where the bitumen flecks coalesce
and grow in size, and the bitumen flecks may contact air bubbles
and coat them to become aerated bitumen; and removing the bitumen
froth from the slurry in an extraction plant comprising one or more
separators (for example, a primary separation vessel or PSV).
[0004] Currently, all of the applicant's primary crushing plants
are located at grade, adjacent to the mine pits, so that all ore
must be trucked out of the pit and up an additional .about.20 m
ramp in order to dump the ore into the primary crusher hopper. This
average haul distance is currently 4-5 km and future ore bodies
would require truck hauls of 10-20 km to existing primary crusher
locations. Once the ore is crushed, the crushed ore is conveyed
from the discharge of the primary crusher to a surge pile, which is
in turn fed to the slurry preparation plant. At present, the
applicant operates both semi-mobile and fixed location slurry
preparation plants. Even though the applicant's primary crushers
are semi-mobile, in order to relocate the semi-mobile crushers, a
.about.20 m tall Mechanically Stabilized Earth (MSE) wall needs to
be constructed, which takes 12-18 months and costs a great deal of
money. Thus, due to the time and expense, it is impractical to
relocate the primary crushers to keep them close to the mining
face.
[0005] The applicant currently operates its hydrotransport systems
(pipelines) at 45-50 .degree. C. and 100-125 mm nominal ore top
size. For these systems, around 10 minutes is the minimum residence
time in the pipeline to achieve sufficient oil sand conditioning in
order to get acceptable primary bitumen recovery in the PSV. Thus,
the equivalent minimum hydrotransport pipeline length is about 3
km, however, can be longer, for example, 4.5 km, which is
equivalent to 18-20 minutes residence time. Optionally, oversize
material (>50 mm) may be screened prior to the extraction plant,
but other than this, all coarse solids are sent through the PSV and
then must travel through coarse tailings systems to the tailings
deposition areas. Oil sand is about 85% solids, which can be
considered waste, and about 70% of the solids could be considered
`coarse` (i.e., >44 .mu.m). The average total travel distance
for this coarse waste material is currently 15-20 km. Hence, both
front-end truck haul and back-end tailings pumping distances will
increase as operations move to more remote ore bodies throughout
the next 8-50 years.
[0006] Operating costs for these semi-remote mineable oil sand ore
bodies will increase significantly from today's costs, due to long
truck hauls and long-distance waste hydrotransport. "Semi-remote"
is defined herein as an ore body having a centroid more than 6-8 km
from an existing extraction plant. Thus, there is a need for
improved equipment layouts in order to deal with these semi-remote
sites and minimize truck haul distances and minimize waste
handling. Although the equipment layouts described herein are
described in relation to oil sand ore bodies, it is understood that
these equipment layouts could offer benefits in almost any
scenario.
SUMMARY OF THE INVENTION
[0007] In one aspect, a process line is provided comprising a
combination of three semi-mobile technologies that will minimize
truck haul distances and minimize waste handling (e.g., coarse
tailings disposal). In one embodiment, the process line comprises:
a semi-mobile crushing station for receiving as-mined oil sand ore
and comminuting the oil sand ore to a first size; a semi-mobile
compact slurry preparation unit for receiving the comminuted oil
sand ore and mixing the oil sand ore with water to form an oil sand
slurry; and a semi-mobile solids removal assembly for removing a
portion of the coarse solids from the oil sand slurry prior to
extracting from the slurry an enriched bitumen froth.
[0008] In one embodiment, the semi-mobile solids removal assembly
comprises a semi-mobile desanding assembly. In one embodiment, the
semi-mobile solids removal assembly comprises a semi-mobile
screening assembly. In one embodiment, the semi-mobile solids
removal assembly comprises a semi-mobile screening assembly and a
semi-mobile desanding assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] 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 following figures.
It is understood that the drawings provided herein are for
illustration purposes only and are not necessarily drawn to
scale.
[0010] FIG. 1 is a schematic depiction of one embodiment of the
process line of the present invention.
[0011] FIG. 2 is a schematic depiction of another embodiment of the
process line of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] 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.
[0013] As used herein, "semi-mobile" equipment refers to equipment
that is designed to be relatively easy to relocate (i.e.,
relocateable) but which generally does not move on a regular hourly
or daily basis as mobile shovels and trucks do.
[0014] FIG. 1 illustrates one embodiment of the present process
line. In this embodiment, the mine face 2 is a mine face in a
mineable oil sand mine or pit. A mining shovel 3 is used to
excavate the oil sand ore at the mine face 2 and it is operative to
advance along the mine face 2 and deposit the as-mined oil sand ore
into mobile trucks 4. The mobile trucks 4 deliver the as-mined oil
sand ore to a semi-mobile crushing station 5. In the embodiment
shown in FIG. 1, semi-mobile crushing station 5 for receiving
as-mined oil sand ore and comminuting the oil sand ore to a first
size is a dual truck mobile sizer (DTMS) such as described in
Canadian Patent No. 2,737,492. As used in the present invention,
the DTMS is considered to be semi-mobile, as it is anticipated that
the DTMS will only have to be relocated every year or so. It is
understood, however, that other moveable crushing units known in
the art can also be used in the present invention.
[0015] In the embodiment shown in FIG. 1, the DTMS generally
comprises an integral rock crusher and discharge conveyor that is
movable under its own power and may receive and comminute
excavated/mined oil sand ore from two earth moving vehicles, in
particular dump trucks, at the same time. In one embodiment, the
DTMS comprises two spaced apart pivoting truck skips having hinged
floors for receiving/feeding the mined ore to a sizer having two
parallel oppositely rotatable rock crushing drums. The comminuted
ore is then discharged onto a discharge conveyor. Because the DTMS
is relocatable by using crawlers and the like, it can follow the
ore body that is being mined so that there will only need to be
short truck hauls (e.g., 1-3 km). The DTMS serves as a Mobile Truck
Conveyor Interface or MTCI, Thus, DTMS is deployed to enable
perpetual short-haul.
[0016] A short conveyor 8 receives the comminuted oil sand ore from
the discharge conveyor of the DTMS and delivers the comminuted oil
sand ore to a semi-mobile compact slurry preparation (CSP) unit 6.
In this embodiment, the semi-mobile compact slurry preparation unit
6 is a wet crushing unit as described in Canadian Patent No.
2,480,122. Semi-mobile compact slurry preparation unit 6 generally
comprises a surge pile 10, apron feeders 12/13, ore sizing
equipment 14 and slurry pumps 25, and can be moved by means of
tracks 27, so that the entire unit may periodically be advanced to
a new location. It is understood, however, that any semi-mobile,
relocatable slurry preparation unit or assembly can be used. Thus,
the feed wetting point step, or oil sand slurry preparation step,
can be moved as close as possible to mine face 2, i.e., in-pit or
near-pit crest.
[0017] Oil sand slurry prepared in the semi-mobile compact slurry
preparation unit 6 can then be transported and conditioned in
hydrotransport pipeline 28. Hydrotransport pipeline 28 is generally
around 3-4.5 km in length, its length being sufficient to ensure
proper conditioning of the oil sand slurry, Thus, hydrotransport
pipeline 28 receives oil sand slurry from semi-mobile compact
slurry preparation unit 6, transports the slurry while
simultaneously conditioning it, and delivers the conditioned slurry
to a semi-mobile solids removal assembly. In this embodiment, the
semi-mobile solids removal assembly is a semi-mobile desanding
assembly 29 for removing a portion of the coarse solids and sand
therefrom. In one embodiment, semi-mobile desanding assembly 29
comprises a near pit desander (NPD), or separator, as described in
Canadian Patent Application No. 2,809,959. In this embodiment, NPD
is moveable by means of tracks 27. It is understood, however, that
other moveable desanders or desanding circuits can be used.
[0018] The semi-mobile desanding assembly 29 produces a relatively
clean (i.e., relatively free from bitumen) coarse solids underflow
31, which only needs to be transported a short distance to sand
storage 32, The reduced solids upper zone or overflow 30 comprises
bitumen, fines and water and is amenable to long distance transport
through a pipeline to a bitumen extraction plant for
polishing/water reheat and return. It was discovered that desanded
oil sand slurry could be pumped long distances, has a lower power
constraint and produces low wear on downstream equipment.
[0019] The inherent operating cost of haul trucks is over three
times that of conveying or hydrotransport, due to differences in
many factors such as energy efficiency, maintenance requirements
and workforce. However, trucks provide a mobile, flexible front end
to the mining process, so it is not likely optimal to eliminate
them entirely. One key advantage provided by trucks is the ability
to seamlessly deal with interburden in the ore body and ore
blending for recovery, simply by dispatching the trucks
appropriately. Second, a short front-end haul serves to minimize
the number of relocations required for the crushing and slurry
preparation plants, which may weigh several thousand
tonnes--without trucks, this weight would need to be moved
continuously, to follow the shovels.
[0020] The DTMS system, which was developed by FLSmidth.TM., is
well-suited to minimizing oil sand hauling distances. The average
haul distance could be reduced, for example, to about 2 km or less
and multiple DTMS systems may be deployed in an oil sand mine. The
DTMS is a semi-mobile truck/conveyor interface, which includes
primary crushing to allow for reliable conveyor operation. One of
the advantages of DTMS is that it eliminates the need for an MSE
wall because it uses hydraulics to lift the ore into the crusher
hopper, rather than an earthworks ramp and the truck engines.
[0021] To remain close to the active mine faces, it is contemplated
that one would be able to relocate the DTMS system and extend the
take-away conveyor network within a two-week window, and this could
be conducted on an annual basis. On the other hand, it is
contemplated that the semi-mobile compact slurry preparation unit
and the semi-mobile desanding assembly would be more costly and
complex moves and may stay in one location for a longer period.
[0022] The lowest operating cost for the present process line is
achieved when the hydrotransport process is started as soon as
possible. Once the optimal hydrotransport distance/residence time
is reached, there is negative value in moving the coarse solids any
further. Thus, a desander may be implemented to reduce the solid
content of the oil sand slurry prior to bitumen extraction. In one
embodiment, a desander similar to a Primary Separation Vessel (PSV)
can be used. In one embodiment, using an 8000 m.sup.3 vessel, up to
90% of the feed solids in the conditioned oil sand slurry from the
hydrotransport system can be separated from the bitumen and fines,
with about a 3.5% bitumen loss to tailings.
[0023] Operating cost for a slurry pumping system is relative to
the mass transported. Thus, by removing 70% to 90% of the solids,
the required energy, wear and capital costs all decline
significantly. The resulting de-sanded slurry is also much easier
to transport over long distances. The desanding vessel would be
optimally located near the tailings deposition area, which may be
an exhausted mine pit, to minimize the total transport distance of
the coarse solids. In addition, by removing much of the sand prior
to bitumen extraction, a higher quality and lower solids product
would be delivered to extraction facilities. This would result in a
higher residence time in separation vessels (such as existing PSVs)
due to a reduction of flow rate, as a large fraction of flow has
been diverted at the desander. In turn, this would result in
bitumen yield uplift, as product quality is improved down the
entire process stream.
[0024] FIG. 2 illustrates another embodiment of the present process
line. In this embodiment, the mine face 102 is a mine face in a
mineable oil sand mine or pit. A mining shovel 103 is used to
excavate the oil sand ore at the mine face 102 and it is operative
to advance along the mine face 102 and deposit the as-mined oil
sand ore into mobile trucks 104. The mobile trucks 104 deliver the
as-mined oil sand ore to a semi-mobile crushing station 105. In the
embodiment shown in FIG. 2, semi-mobile crushing station 105 for
receiving as-mined oil sand ore and comminuting the oil sand ore to
a first size is a dual truck mobile sizer (DTMS) such as described
in Canadian Patent No. 2,737,492.
[0025] A. short conveyor 108 receives the comminuted oil sand ore
from the discharge conveyor of the semi-mobile crushing station 105
and delivers the comminuted oil sand ore to a semi-mobile compact
slurry preparation (CSP) unit 106. In this embodiment, the
semi-mobile compact slurry preparation unit 106 is a wet crushing
unit as described in Canadian Patent No. 2,480,122. Oil sand slurry
prepared in the semi-mobile compact slurry preparation unit 106 can
then be transported and conditioned in hydrotransport pipeline 128.
Hydrotransport pipeline 128 is generally around 3-4.5 km in length,
its length being sufficient to ensure proper conditioning of the
oil sand slurry.
[0026] In this embodiment, the hydrotransport pipeline 128 receives
oil sand slurry from semi-mobile compact slurry preparation unit
106, transports the slurry while simultaneously conditioning it,
and delivers the conditioned slurry to a semi-mobile solids removal
assembly which comprises a screening assembly 140 for removing a
portion of the coarse solids, in particular, lumps and rocks,
therefrom. Screening assembly 140 comprises a slurry screen for
scalping/removal of wear-inducing lumps in the conditioned slurry
down to a nominal size (e.g. about 12 to 15 mm and larger is
removed). Screening assembly 140 may be relocatable by means of
tracks 127. In one embodiment, the screening assembly 140 may be
positioned further upstream, i.e., along the hydrotransport
pipeline 128, before the oil sand slurry is fully conditioned.
There may be instances where it is more desirable to remove the
clay lumps and rocks as soon as possible, so there will be an
optimal screening assembly location, where oil sand lumps have been
ablated just below the screen cut size, for example, 1.5-2.5 km
from the start of the hydrotransport pipeline 128.
[0027] In one embodiment, about 10% of solids in the conditioned
slurry are removed by use of the screening assembly. Removal of
larger rocks and clay lumps may provide one or more of the
following benefits: lower wear on downstream equipment; improved
(unhindered) settling at sand separation stage; reduce solids
(including clay clumps) directed to tailings ponds; and residual
value of screenings (lumpy waste) in context of viable construction
materials for temporary haul routes. Generally, rocks/lumps above
12 mm cause the majority of pump, pipeline and vessel wear. By
removing these lumps, it will allow for cost-effective
long-distance pipeline transport to extraction, which is especially
important if bitumen extraction equipment such as a primary
separation vessel (PSV) is far from the mine. Also, removal of the
clay lumps at this stage means less fluid fine tailings (which are
primarily clay) are formed in tailings ponds. The lumps 142
(rejects) removed from the conditioned slurry can be transported a
short distance to a lump storage facility.
[0028] In one embodiment, the screened slurry 144, which still
includes sand, may be directly transported to bitumen extraction
facilities. In another embodiment, the semi-mobile solids removal
assembly further comprises a semi-mobile desanding assembly 129 for
removing a portion of the sand still present in screened slurry
144. The semi-mobile desanding assembly 129 may comprise a near pit
desander (NPD), or separator, as described in Canadian Patent
Application No. 2,809,959, which is moveable by means of tracks
127. It is understood, however, that other moveable desanders or
desanding circuits can be used. In this embodiment, a relatively
clean (i.e., relatively free from bitumen) sand underflow 148 is
produced which only needs to be transported a short distance to
sand storage. The reduced solids upper zone or overflow 146
comprises bitumen, fines and water and is amenable to long distance
transport through a pipeline to a bitumen extraction plant for
polishing/water reheat and return.
[0029] From the foregoing description, one skilled in the art can
easily ascertain the essential characteristics of this invention.
However, the scope of the claims should not be limited by the
preferred embodiments set forth in the examples, but should be
given the broadest interpretation consistent with the description
as a whole.
* * * * *