Note: Descriptions are shown in the official language in which they were submitted.
CA 02705058 2014-12-10
=
1
METHODS AND DEVICES FOR DEPOSITING FLOCCULATED FINE TAILINGS
Field of the invention:
The present invention relates to a deposition method for applications
typically
used in of the oil and gas industry. More particularly, the present invention
relates to
a method and to a corresponding device for improving the deposition of
flocculated
oil sand fine tailings (hereinafter referred to also as flocculated "mature
fine tailings"
(MFT)) into a deposition containment area, such a deposition cell, for
example.
Background of the invention:
Oil sand fine tailings have become a technical, operational, environmental,
economic and public policy issue.
Oil sand tailings are generated from hydrocarbon extraction process
operations that separate the valuable hydrocarbons from oil sand ore. All
commercial hydrocarbon extraction processes use variations of the Clark Hot
Water
Process in which water is added to the oil sands to enable the separation of
the
valuable hydrocarbon fraction from the oil sand minerals. The process water
also
acts as a carrier fluid for the mineral fraction. Once the hydrocarbon
fraction is
recovered, the residual water, unrecovered hydrocarbons and minerals are
generally
referred to as "tailings".
The oil sand industry has adopted a convention with respect to mineral
particle sizing. Mineral fractions with a particle diameter greater than 44
microns are
referred to as "sand". Mineral fractions with a particle diameter less than 44
microns
are referred to as "fines". Mineral fractions with a particle diameter less
than 2
microns are generally referred to as "clay", but in some instances "clay" may
refer to
the actual particle mineralogy. The relationship between sand and fines in
tailings
CA 02705058 2010-05-20
,
,
2
reflects the variation in the oil sand ore make-up, the chemistry of the
process water
and the extraction process.
Conventionally, tailings are transported to a deposition site generally
referred
to as a "tailings pond" located close to the oil sands mining and extraction
facilities to
facilitate pipeline transportation, discharging and management of the
tailings. Due to
the scale of operations, oil sand tailings ponds cover vast tracts of land and
must be
constructed and managed in accordance with regulations. The management of pond
location, filling, level control and reclamation is a complex undertaking
given the
geographical, technical, regulatory and economic constraints of oil sands
operations.
Each tailings pond is contained within a dyke structure generally constructed
by placing the sand fraction of the tailings within cells or on beaches. The
process
water, unrecovered hydrocarbons, together with sand and fine minerals not
trapped
in the dyke structure flow into the tailings pond. Tailings streams initially
discharged
into the ponds may have fairly low densities and solids contents, for instance
around
is 0.5-10 wt%.
In the tailings pond, the process water, unrecovered hydrocarbons and
minerals settle naturally to form different strata. The upper stratum is
primarily water
that may be recycled as process water to the extraction process. The lower
stratum
contains settled residual hydrocarbon and minerals which are predominately
fines.
This lower stratum is often referred to as "mature fine tailings" (MFT).
Mature fine
tailings have very slow consolidation rates and represent a major challenge to
tailings management in the oil sands industry.
The composition of mature fine tailings is highly variable. Near the top of
the
stratum the mineral content is about 10 wt% and through time consolidates up
to 50
wt% at the bottom of the stratum. Overall, mature fine tailings have an
average
mineral content of about 30 wt%. While fines are the dominant particle size
fraction
CA 02705058 2010-05-20
3
in the mineral content, the sand content may be 15 wt% of the solids and the
clay
content may be up to 75 wt% of the solids, reflecting the oil sand ore and
extraction
process. Additional variation may result from the residual hydrocarbon which
may be
dispersed in the mineral or may segregate into mat layers of hydrocarbon. The
mature fine tailings in a pond not only has a wide variation of compositions
distributed from top to bottom of the pond but there may also be pockets of
different
compositions at random locations throughout the pond.
Mature fine tailings behave as a fluid-like colloidal material. The fact that
mature fine tailings behave as a fluid significantly limits options to reclaim
tailings
ponds. In addition, mature fine tailings do not behave as a Newtonian fluid,
which
makes continuous commercial scale treatments for dewatering the tailings all
the
more challenging. Without dewatering or solidifying the mature fine tailings,
tailings
ponds have increasing economic and environmental implications over time.
There are some methods that have been proposed for disposing of or
reclaiming oil sand tailings by attempting to solidify or dewater mature fine
tailings. If
mature fine tailings can be sufficiently dewatered so as to convert the waste
product
into a reclaimed firm terrain, then many of the problems associated with this
material
can be curtailed or completely avoided. As a general guideline target,
achieving a
solids content of 75 wt% for mature fine tailings is considered sufficiently
"dried" for
reclamation.
One known method for dewatering MFT involves a freeze-thaw approach.
Several field trials were conducted at oil sands sites by depositing MFT into
small,
shallow pits that were allowed to freeze over the winter and undergo thawing
and
evaporative dewatering the following summer. Scale up of such a method would
require enormous surface areas and would be highly dependent on weather and
season. Furthermore, other restrictions of this setup were the collection of
release
CA 02705058 2010-05-20
,
,
4
water and precipitation on the surface of the MFT which discounted the
efficacy of
the evaporative drying mechanism.
Some other known methods have attempted to treat MFT with the addition of
a chemical to create a thickened paste that will solidify or eventually
dewater.
One such method, referred to as "consolidated tailings" (CT), involves
combining mature fine tailings with sand and gypsum. A typical consolidated
tailings
mixture is about 60 wt% mineral (balance is process water) with a sand to
fines ratio
of about 4 to 1, and about 600 to 1000 ppm of gypsum. This combination can
result
in a non-segregating mixture when deposited into the tailings ponds for
consolidation. However, the CT method has a number of drawbacks. It relies on
continuous extraction operations for a supply of sand, gypsum and process
water.
The blend must be tightly controlled. Also, when consolidated tailings
mixtures are
less than 60 wt% mineral, the material segregates with a portion of the fines
returned
to the pond for reprocessing when settled as mature fine tailings.
Furthermore, the
geotechnical strength of the deposited consolidated tailings requires
containment
dykes and, therefore, the sand required in CT competes with sand used for dyke
construction until extraction operations cease. Without sand, the CT method
cannot
treat mature fine tailings.
Another method conducted at lab-scale sought to dilute MFT preferably to 10
wt% solids before adding Percol LT27A or 156. Though the more diluted MFT
showed faster settling rates and resulted in a thickened paste, this dilution-
dependent small batch method could not achieve the required dewatering results
for
reclamation of mature fine tailings.
Some other methods have attempted to use polymers or other chemicals to
help dewater MFT. However, these methods have encountered various problems
and have been unable to achieve reliable results. When generally considering
CA 02705058 2010-05-20
,
methods comprising chemical addition followed by tailings deposition for
dewatering,
there are a number of important factors that should not be overlooked.
Of course, one factor is the nature, properties and effects of the added
chemicals. The chemicals that have shown promise up to now have been dependent
5
on oil sand extraction by-products, effective only at lab-scale or within
narrow
process operating windows, or unable to properly and reliably mix, react or be
transported with tailings. Some added chemicals have enabled thickening of the
tailings with no change in solids content by entrapping water within the
material,
which limits the water recovery options from the deposited material. Some
chemical
additives such as gypsum and hydrated lime have generated water runoff that
can
adversely impact the process water reused in the extraction processes or dried
tailings with a high salt content that is unsuitable for reclamation.
Another factor is the chemical addition technique. Known techniques of
adding sand or chemicals often involve blending materials in a tank or
thickener
apparatus. Such known techniques have several disadvantages including
requiring a
controlled, homogeneous mixing of the additive in a stream with varying
composition
and flows which results in inefficiency and restricts operational flexibility.
Some
chemical additives also have a certain degree of fragility, changeability or
reactivity
that requires special care in their application.
Another factor is that many chemical additives can be very viscous and may
exhibit non-Newtonian fluid behaviour. Several known techniques rely on
dilution so
that the combined fluid can be approximated as a Newtonian fluid with respect
to
mixing and hydraulic processes. Mature fine tailings, however, particularly at
high
mineral or clay concentrations, demonstrates non-Newtonian fluid behaviour.
Consequently, even though a chemical additive may show promise as a dewatering
agent in the lab or small scale batch trials, it is difficult to repeat
performance in an
up-scaled or commercial facility. This problem was demonstrated when
attempting to
CA 02705058 2010-05-20
6
inject a viscous polymer additive into a pipe carrying MFT. The main MFT
pipeline
was intersected by a smaller side branch pipe for injecting the polymer
additive. For
Newtonian fluids, one would expect this arrangement to allow high turbulence
to aid
mixing. However, for the two non-Newtonian fluids, the field performance with
this
mixing arrangement was inconsistent and inadequate. There are various reasons
why such mixing arrangements encounter problems. When the additive is injected
in
such a way, it may have a tendency to congregate at the top or bottom of the
MFT
stream depending on its density relative to MFT and the injection direction
relative to
the flow direction. For non-Newtonian fluids, such as Bingham fluids, the
fluid
essentially flows as a plug down the pipe with low internal turbulence in the
region of
the plug. Also, when the chemical additive reacts quickly with the MFT, a thin
reacted region may form on the outside of the additive plug thus separating
unreacted chemical additive and unreacted MFT.
Inadequate mixing can greatly decrease the efficiency of the chemical additive
and even short-circuit the entire dewatering process. Inadequate mixing also
results
in inefficient use of the chemical additives, some of which remain unmixed and
unreacted and cannot be recovered. Known techniques have several disadvantages
including the inability to achieve a controlled, reliable or adequate mixing
of the
chemical additive as well as poor efficiency and flexibility of the process.
Still another factor is the technique of handling the oil sand tailings after
chemical addition. If oil sand tailings are not handled properly, dewatering
may be
decreased or altogether prevented. In some past trials, handling was not
managed
or controlled and resulted in unreliable dewatering performance. Some
techniques
such as in CIBA's Canadian patent application No. 2,512,324 (SCHAFFER et al.)
have attempted to simply inject the chemical into the pipeline without a
methodology
to reliably adapt to changing oil sand tailings compositions, flow rates,
hydraulic
properties or the nature of particular chemical additive. Relying solely on
this ignores
the complex nature of mixing and treating oil sand tailings and significantly
hampers
CA 02705058 2010-05-20
7
the flexibility and reliability of the system. When the chemical addition and
subsequent handling have been approached in such an uncontrolled, trial-and-
error
fashion, the dewatering performance has been unachievable.
Yet another factor is the technique of handling or treating the MFT prior to
chemical addition. MFT is drawn up by pumps or dredging equipment from
tailings
ponds and preferably sent via pipeline to the dewatering treatment area. The
tailings
ponds, however, may contain a variety of materials that could disrupt the MFT
dewatering process. For instance, in the raw MFT there may be mats of bitumen,
particularly in the cold winter months. There may also be other extraneous
debris
1.0 such as pieces of wood, glass, plastic, metal or natural organic
material that can be
entrained with the MFT as it is taken from the pond. Such unwanted materials
can
interfere with the MFT process equipment and chemistry.
Given the significant inventory and ongoing production of MFT at oil sands
operations, there is a need for techniques and advances that can enable MFT
drying
for conversion into reclaimable landscapes.
Known to the applicant are the following publications and patent documents,
namely: OWEN, A.T. et al. "Using turbulent pipe flow to study the factors
affecting
polymer-bridging flocculation of mineral systems", International Journal of
Mineral
Processing, Vol. 87, Issues 3-4, July 2nd, 2008; VRALE et al., "Rapid Mixing
in
Water," Jour. AWWA, Jan., 1971; WO 2002/079099 Al (BRANNING, L.); WO
2009/009887 Al (BOZAK, R. et al.); and US 5,839,828 (GLANVILLE, R.).
However, none of these prior art documents seem to teach, illustrate or even
suggest a solution which is intended to improve the deposition of flocculated
mature
fine tailings into a deposition containment area, in a simple, efficient and
cost-
effective manner.
CA 02705058 2010-05-20
8
Indeed, it is known in the art that in the case of tailings reduction
operations,
extra mixing of the MFT and flocculent agent, such as polymer for example, are
often required at a point in the process where the fluid medium is highly
sensitive to
shear forces, namely just prior to cell deposition. Typical in-line mixing
devices
introduce high amounts of shear forces which tend to break up the flocculated
MFT
in their attempt to provide mixing, such break up being very disadvantageous
and
undesirable for obvious reasons. Therefore, it would be very useful to provide
a
solution that enables improved mixing of un-reacted polymer while minimizing
additional shear forces on the existing mixed material.
Hence, in light of the aforementioned, there is a need for a new method or
device which would be able to overcome or at least minimize some of the above-
discussed prior art concerns.
Summary of the invention:
An object of the present invention is to provide a device, which by virtue of
its
design and components, satisfies some of the above-mentioned needs and is thus
an improvement over other related devices and/or methods known in the prior
art.
In accordance with the present invention, the above object is achieved, as
will
be easily understood, with a device such as the one briefly described herein,
and
such as the one exemplified in the accompanying drawings.
More particularly, the present invention relates to a deposition device for an
additional mixing of mature fine tailings with residual flocculating agent
prior to
depositing into a deposition cell, the deposition device comprising:
- an inlet for receiving a fluid flow of flocculated mature fine tailings and
residual flocculating agent from an in-line feed;
CA 02705058 2010-05-20
9
- an accumulation chamber for accumulating the fluid flow from the inlet,
the
accumulation chamber being configured for reducing the flow velocity of the
fluid
flow and for raising said fluid flow up to a predetermined height;
- an overflow interface provided at the predetermined height for allowing
the
fluid flow to overflow from the accumulation chamber; and
- a descent assembly for receiving the fluid flow overflowing from the
accumulation chamber via the overflow interface, and for allowing said fluid
flow to
descend to at least one lower height, the descent assembly being configured so
that
residual flocculating agent from the fluid flow is additionally mixed with
mature fine
tailings from said fluid flow when the fluid flow is traveling down the
descent
assembly from an upper region to a lower region, the descent assembly being
further configured for preventing overshearing of the flocculated mature fine
tailings
prior to depositing into the deposition cell.
According to another aspect of the present invention, there is also provided a
kit with components for assembling the above-mentioned injection device.
According to yet another aspect of the present invention, there is also
provided a conversion kit including the above-mentioned device and/or
components.
According to yet another aspect of the present invention, there is also
provided a set of components for interchanging with components of above-
mentioned device and/or kit.
According to yet another aspect of the present invention, there is also
provided a method for assembling components of the above-mentioned kit and/or
set.
CA 02705058 2010-05-20
According to yet another aspect of the present invention, there is also
provided a method of using the above-mentioned device, kit, set and/or
components
thereof.
According to yet another aspect of the present invention, there is also
5 provided a corresponding pipeline carrying flocculated mature fine
tailings, the
pipeline having been assembled with the above-mentioned device, conversion
kit,
set and/or method(s).
According to yet another aspect of the present invention, there is also
provided a method of manufacturing the above-mentioned device, corresponding
kit
lo and/or conversion set.
According to yet another aspect of the present invention, there is also
provided a method of treating a fluid flow of flocculated mature fine tailings
prior to
depositing.
More particularly, the present invention also relates to a method for
additionally mixing mature fine tailings with residual flocculating agent
prior to
depositing into a deposition cell, the method comprising the steps of:
a) receiving a fluid flow of flocculated mature fine tailings and residual
flocculating agent from an in-line feed;
b) reducing the flow velocity of the fluid flow and accumulating said fluid
flow
inside a chamber up to a predetermined height; and
c) allowing the fluid flow to flow down a descent assembly so as to descend
from the predetermined height to at least one lower height, the descent
assembly
being configured so that residual flocculating agent from the fluid flow is
additionally
mixed with mature fine tailings from said fluid flow when the fluid flow
travels down
the descent assembly from an upper region to a lower region, the descent
assembly
CA 02705058 2014-12-10
,
11
being further configured for preventing overshearing of the flocculated mature
fine
tailings.
In some aspects, there is provided a deposition device for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition device comprising:
an inlet for receiving a continuous flow of material comprising flocculated
oil
sand fine tailings; and
a chamber delimited by walls, the chamber comprising:
a lower region in fluid communication with the inlet, the walls being
positioned, shaped and sized to allow a reduction in velocity and mixing of
the material entering the lower region;
an upper region located above the lower region and interfacing with the
same so as to receive the material therefrom; and
an overflow area for allowing the material to spill out of the upper region,
the overflow area being configured to be spaced relative to the deposition
surface so as to avoid overshear of the flocculated fine tailings when the
material is spilled thereon; and
wherein the deposition device is configured such that the flocculated fine
tailings spilled from the overflow area onto the deposition surface are formed
prior to entering the inlet of the deposition device.
In some aspects, there is provided a deposition method for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition method comprising:
CA 02705058 2014-12-10
,
,
11a
providing an in-line continuous flow of material comprising flocculated oil
sand
fine tailings;
providing a chamber comprising a lower region, and an upper region located
above and interfacing with the lower region;
introducing the material into the lower region of the chamber to allow
reduction
in velocity and mixing of the material therein; and
allowing the material to fill and spill out of the upper region of the chamber
so
as to avoid overshear of the flocculated fine tailings when the material is
spilled
onto a deposition surface, wherein the flocculated fine tailings spilled from
the
overflow area onto the deposition surface are formed prior to entering into
the
lower region of the chamber.
In some aspects, there is provided a deposition device for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition device comprising:
an inlet for receiving a continuous flow of material comprising flocculated
oil
sand fine tailings; and
a cascading compartment in fluid communication with the inlet, the cascading
compartment comprising:
a base and side walls defining a channel;
the side walls being spaced apart to allow a reduction in velocity of the
flow of the material;
a plurality of baffles projecting upwardly from the base into the channel to
cause a cascading flow of the material; and
an outlet portion for releasing the material onto the deposition surface; and
CA 02705058 2014-12-10
,
11b
wherein the deposition device is configured such that the flocculated fine
tailings released from the outlet portion onto the deposition surface are
formed
prior to entering the inlet of the deposition device.
In some aspects, there is provided a deposition method for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition method comprising:
providing an in-line continuous flow of material comprising flocculated oil
sand
fine tailings;
simultaneously reducing the velocity of the flow and cascading the material
over
a plurality of baffles within a cascade compartment; and
releasing the material from the cascading compartment onto a deposition
surface, wherein the flocculated fine tailings released onto the deposition
surface are formed prior to the cascading compartment.
In some aspects, there is provided a deposition device for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition device comprising:
an inlet for receiving a continuous flow of material comprising flocculated
oil
sand fine tailings;
a chamber delimited by walls, the chamber comprising:
a lower region in fluid communication with the inlet, the walls being
positioned, shaped and sized to allow a reduction in velocity and mixing of
the material entering the lower region;
an upper region located above the lower region and interfacing with the
same so as to receive the material therefrom; and
CA 02705058 2014-12-10
11C
an overflow area for allowing the material to spill out of the upper region,
the overflow area being configured to be spaced relative to the deposition
surface so as to avoid overshear of the flocculated fine tailings when the
material is spilled thereon; and
a cascading compartment having:
a base and side walls defining a channel adapted to receive the material
from the overflow area; and
a plurality of baffles projecting upwardly from the base into the channel to
cause a cascading flow of the material toward the deposition surface.
In some aspects, there is provided a deposition method for improving the
depositing of flocculated oil sands fine tailings into a deposition
containment area
having a deposition surface, the deposition method comprising:
adding a flocculant to an oil sand fine tailings material to form flocculated
oil
sand fine tailings;
providing an in-line continuous flow of material comprising the flocculated
oil
sand fine tailings;
simultaneously reducing the velocity of the flow and cascading the material
over
a plurality of baffles within a cascade compartment; and
releasing the material from the cascading compartment onto a deposition
surface;
wherein additional flocculant addition is avoided during and after deposition.
CA 02705058 2014-12-10
,
,
11d
The objects, advantages and other features of the present invention will
become more apparent upon reading of the following non-restrictive description
of
preferred embodiments thereof, given for the purpose of exemplification only,
with
reference to the accompanying drawings.
Brief description of the drawings.
Figure 1 is a front perspective view of a deposition device according to a
first
preferred embodiment of the present invention.
Figure 2 is rear perspective view of what is shown in Figure 1.
Figure 3 is a front perspective view of a housing according to a preferred
embodiment of the present invention.
Figure 4 is an elevational view of a side wall of a housing provided with a
pair
of lifting components according to a preferred embodiment of the present
invention.
Figure 5 is a top view of what is shown in Figure 3.
Figure 6 is a rear view of what is shown in Figure 3.
Figure 7 is a perspective view of a base according to a preferred embodiment
of the present invention.
Figure 8 is a side devotional view of what is shown in Figure 7.
Figure 9 is top view of what is shown in Figure 7.
______--------__
CA 02705058 2010-05-20
12
Figure 10 is a perspective view of a lifting component according to a
preferred
embodiment of the present invention.
Figure 11 is a side view of what is shown in Figure 10.
Figure 12 is a front view of what is shown in Figure 10.
Figure 13 is a top view of what is shown in Figure 10.
Figure 14 is a front view of a lifting lug of the lifting component shown in
Figure 10.
Figure 15 is a top view of what is shown in Figure 14.
Figure 16 is a perspective view of a partitioning wall having opposite side
edges removably mounted onto corresponding opposite slots each being defined
by
a pair of corresponding guides according to a preferred embodiment of the
present
invention.
Figure 17 is a front view of what is shown in Figure 16.
Figure 18 is a top view of what is shown in Figure 16.
Figure 19 is a schematic representation of a base of a housing of a deposition
device provided with at least one reinforcement component according to a
preferred
embodiment of the present invention.
Figure 20 is a side view of the reinforcement component shown in Figure 19.
Figure 21 is a front view of what is shown in Figure 20.
CA 02705058 2010-05-20
,
13
Figure 22 is a perspective view of a flange connection intended to be used
with an inlet of a deposition device according to a preferred embodiment of
the
present invention.
Figure 23 is a side view of what is shown in Figure 22.
Figure 24 is a front view of what is shown in Figure 23.
Figure 25 is a perspective view of a deposition device according to another
preferred embodiment of the present invention.
Figure 26 is a top view of what is shown in Figure 25.
Figure 27 is a side view of what is shown in Figure 25.
Figure 28 is a front view of what is shown in Figure 25.
Figure 29 is a partial cross-sectional view taken along a longitudinal axis of
the deposition device shown in Figure 25.
Figure 30 is a top perspective view of a deposition device according to yet
another preferred embodiment of the present invention.
Figure 31 is a side elevational view of what is shown in Figure 30.
Figure 32 is a top plan view of what is shown in Figure 30.
Figure 33 is a front view of what is shown in Figure 30.
Figure 34 is a top perspective view of the vertical pipe, corresponding feed
pipe and supports, shown in Figure 30.
CA 02705058 2010-05-20
,
14
Figure 35 is a side elevational view of what is shown in Figure 34.
Figure 36 is a front view of what is shown in Figure 34.
Figure 37 is a top plan view of what is shown in Figure 34.
Figure 38 is an enlarged front view of a portion of what is shown in Figure
34.
Figure 39 is another top perspective view of what is shown in Figure 34, the
cut-out portion of the vertical pipe being now shown provided with a
corresponding
spill box according to a preferred embodiment of the present invention.
Figure 40 is an enlarged perspective view of the spill box shown in Figure 39.
Figure 41 is a cross-sectional view taken along a central line of what is
shown
1.0 in Figure 40.
Figure 42 is a front view of what is shown in Figure 40.
Figure 43 is a top view of what is shown in Figure 40.
Figure 44 is a perspective view of the ramp assembly shown in Figure 30.
Figure 45 is a side elevational view of what is shown in Figure 44.
Figure 46 is a top plan view of what is shown in Figure 44.
Figure 47 is a front view of what is shown in Figure 44.
Figure 48 is a top plan view of a ramp assembly according to a preferred
embodiment of the present invention.
CA 02705058 2010-05-20
Figure 49 is a side view of a deposition device according to yet another
preferred embodiment of the present invention.
Figure 50 is a top plan view of what is shown in Figure 49.
Figure 51 is an enlarged front view of a portion of what is shown in Figure
49.
5 Detailed description of preferred embodiments of the invention:
In the following description, the same numerical references refer to similar
elements. The embodiments, geometrical configurations, materials mentioned
and/or
dimensions shown in the figures are preferred, given for exemplification
purposes
only.
10 Moreover, although the present invention was primarily designed for
improving deposition of flocculated mature fine tailings (MFT) into a
deposition
containment area, for example, it may be used with other types of substance(s)
and/or liquid(s), for other purposes, and in other fields, as apparent to a
person
skilled in the art. For this reason, expressions such as "depositing",
"flocculated",
15 "MFT", etc. used herein should not be taken as to limit the scope of the
present
invention and includes all other kinds of pipelines, cylinders, items and/or
applications with which the present invention could be used and may be useful.
Moreover, in the context of the present invention, the expressions "device",
"kit", "unit", "cascade", "box", "slide", "ramp", "apparatus", "mechanism",
"assembly",
"system", "set" and any other equivalent expression and/or compound word
thereof
known in the art will be used interchangeably. Furthermore, the same applies
for any
other mutually equivalent and/or complementary expressions, such as "MFT",
"fluid
flow", "material", "medium" and "fluid", as well as "polymer" and
"flocculating agent"
CA 02705058 2010-05-20
16
for example, or even "deposit", "discharge", "overflow" and "release", as well
as
"mixed", "reacted" and "used", as also apparent to a person skilled in the
art.
In addition, although the preferred embodiment of the present invention as
illustrated in the accompanying drawings comprises various components and
although the preferred embodiment of the deposition device as shown consists
of
certain geometrical configurations as explained and illustrated herein, not
all of these
components and geometries are essential to the invention and thus should not
be
taken in their restrictive sense, i.e. should not be taken as to limit the
scope of the
present invention. It is to be understood that other suitable components and
cooperations thereinbetween, as well as other suitable geometrical
configurations
may be used for the deposition device and corresponding parts according to the
present invention, as well as corresponding conversion kit or set, and/or
resulting
pipeline or fitting, as briefly explained herein, or as can be easily inferred
herefrom,
by a person skilled in the art, without departing from the scope of the
present
invention.
List of numerical references for some of the corresponding preferred
components
illustrated in the accompanying drawings:
1. deposition device
3. deposition cell
5. inlet
7. fluid flow
9. accumulation chamber
11. overflow interface
13a. predetermined height
13b. lower height
15. descent assembly
15i. cascading assembly
CA 02705058 2010-05-20
17
15ii. ramp assembly
17a. upper region
17b. lower region
19. step
19b. integrated step (of housing 25)
21. riser
21a. uppermost riser
21b. integrated riser (of housing 25)
23. partitioning plate
23a. drainage hole (of partitioning plate 23)
25. housing
25a. left side wall (of housing 25)
25b. right side wall (of housing 25)
25c. end wall (of housing 25)
25d. bottom wall
27. slot
27a. first guide
27b. second guide
29. reinforcement component (of partitioning plate 23)
31. top edge (of uppermost riser 21a)
33. base
35. flange connection
37. reinforcement component (of housing)
39. lifting component
41. skid base
43. top portion (of ramp assembly 15ii)
45. bottom portion (of ramp assembly 15ii)
47. ramp (of ramp assembly 15ii)
49. ridge (of ramp assembly 15ii)
CA 02705058 2010-05-20
,
18
51. longitudinal axis (of ramp assembly 15ii)
53. containment wall (of ramp assembly 1511)
55. vertical pipe
57. upper cut-out portion (of vertical pipe 55)
59. spill box
61. pin (of spill box 59)
63. hole (of top portion of ramp 47)
65. abutment flange(of spill box 59)
67. feed pipe (of vertical pipe 55)
69. inside portion (of vertical pipe 55)
71. support (of vertical pipe 55)
73. apertures (of vertical pipe 55)
73a. first set of apertures
73b. second set of apertures
A. angle
Broadly described, as exemplified in the accompanying drawings and as can
be easily understood herefrom by a person skilled in the art, the present
invention
relates to a deposition method for improving the depositing of flocculated oil
fine
tailings, hereinafter referred to also as flocculated "mature fine tailings"
(MFT), into a
deposition containment area having a deposition surface, such as a deposition
cell,
for example. Indeed, it is well known in the art that in the case of tailings
reduction
operations, extra mixing of the MFT and flocculent agent, such as a polymer
for
example, are often required at a point in the process where the fluid medium
is
highly sensitive to shear forces, namely just prior to cell deposition.
Typical in-line
mixing devices introduce high amounts of shear forces which tend to break up
the
flocculated MFT in their attempt to provide mixing, such break up being very
disadvantageous and undesirable for obvious reasons. Therefore, the present
CA 02705058 2010-05-20
19
invention aims to provide an improved mixing of un-reacted polymer while
minimizing additional shear forces on the existing flocculated material.
According a preferred aspect of the invention, the method is intended for
additionally mixing mature fine tailings with residual flocculating agent
which may still
be left in the fluid flow (7) of the pipeline carrying the flocculated mature
fine tailings
prior to depositing, in order to not only advantageously use such residual
flocculating
agent which would normally go unused and end up in the deposition cell, but
also for
providing additional flocculation of the mature fine tailings via a mixing
with the
residual flocculating agent for improved dewatering purposes, MFT drying, etc.
The method according to the present invention preferably comprises the steps
of: a) receiving a fluid flow (7) of flocculated mature fine tailings and
residual
flocculating agent from an in-line feed, such as a pipeline for example; b)
reducing
the fluid velocity of the fluid flow (7) and accumulating said fluid flow (7)
inside a
chamber (9) (or a vertical pipe (55), etc.) up to a certain predetermined
height (13a);
and c) allowing the fluid flow (7) to flow down a descent assembly (15) so as
to
descend from the starting predetermined height (13a) to at least one lower
height
(13b), and preferably a plurality or a "cascade" of such lower heights (13b),
the
descent assembly (15) being configured so that residual flocculated agent
which
may be present in the fluid flow (7) is additionally mixed with mature fine
tailings from
said fluid flow (7) when the fluid flow (7) travels down the descent assembly
(15)
from an upper region (17a) to a lower region (17b), the descent assembly (15)
being
further configured for preventing overshearing of the flocculating mature fine
tailings,
thereby enabling to have a gentle mixing of the mature fine tailings with the
flocculating agent, such as a polymer for example, which would otherwise be
wasted
with conventional methods of operation. Indeed, as will be better appreciated
in
greater detail hereinbelow, the present invention is intended namely to
prevent
overshearing of flocculated MET/polymer mixture at the cell deposition point,
and
also reduce unmixed polymer from entering the deposition cell.
CA 02705058 2010-05-20
It is worth mentioning at this point that although a polymer has been given as
a way of an example for a possible flocculating agent for the mature fine
tailings, a
person skilled in the art would understand that various other types of
flocculating
agents, solutions, elements, compounds and/or the like, may be used according
to
5 the present invention in order to provide an additional mixing (reaction,
flocculation,
etc.) of the mature fine tailings with a corresponding suitable flocculating
agent,
depending on the particular applications for which the present method is
intended
for, the factors in place and the desired end results.
Preferably, step a) of the present invention comprises a step of exposing the
10 fluid flow (7) to atmospheric pressure, and steps b) and c) can be done
either
separately, or simultaneously, as apparent to a person skilled in the art.
Preferably
also, the present method further comprises the step of: d) subsequently
depositing
the fluid flow (7) into a deposition cell, for example. It is worth mentioning
that
although the present deposition device (1) could be designed to be operated in
a
15 closed system, it is preferable to have the deposition device (1) open
to atmosphere
because this provides different advantages. Namely, it allows for an easier
cleanout.
Furthermore, it also provides for an aeration of the material which is
believed to aid
in dewatering. Moreover, having a deposition device (1) which is open to
atmosphere allows for the different components thereof to be more easily
20 accessible, inspected, maintained and/or replaced, if need may be.
According to another aspect of the present invention, there is also provided a
deposition method for improving the depositing of flocculated oil fine
tailings into a
deposition containment area having a deposition surface, the deposition method
comprising: a) providing an in-line continuous flow of material comprising
flocculated
oil sand fine tailings; b) providing a chamber comprising a lower region, and
an
upper region located above and interfacing with the lower region; c)
introducing the
material into the lower region of the chamber to allow reduction in velocity
and
mixing of the material therein; and d) allowing the material to fill and spill
out of the
CA 02705058 2010-05-20
,
21
upper region of the chamber so as to avoid overshear of the flocculated fine
tailings
when the material is spilled onto a deposition surface.
The present invention also relates to corresponding a deposition device (1)
which may come in various suitable shapes and forms for carrying out the
different
methods briefly described herein. For example, the present description
describes
three main embodiments of a deposition device (1) and corresponding descent
assembly (15) according to the present invention, the first one being
exemplified in
Figures 1-29 and hereinafter referred to also as a "cascade box", the second
one
being exemplified in Figures 30-48, and hereinafter referred to also as a
"deposition
slide", and the third one being exemplified in Figures 49-51, and referred to
hereinafter also as "stand pipe". The following description will provide more
insight
as to the various aspects, possible variants and resulting advantages of each
one of
these preferred embodiments of the present invention.
Generally speaking, and according to a first given preferred aspect of the
present invention, the deposition device (1) is intended for additional mixing
of
mature fine tailings with residual flocculating agent prior to depositing into
a
deposition cell. As can be easily understood by a person skilled in the art in
view of
the accompanying drawings, the deposition device (1) preferably comprises an
inlet
(5), an accumulation chamber (9), an overflow interface (11) and a descent
assembly (15). The inlet (5) is intended for receiving a fluid flow (7) of
flocculated
mature fine tailings and residual flocculated agent from an in-line feed, such
as a
pipeline carrying the fluid flow (7) to be treated and processed with the
present
deposition device (1) prior to depositing into a deposition cell, for example.
The
accumulation chamber (9) is intended for accumulating the fluid flow (7) from
the
inlet (5), and is preferably configured for reducing the flow velocity of the
fluid flow
(7) and for raising said fluid flow (7) up to a certain predetermined height
(13a).
Preferably also, the overflow interface (11) is provided at the predetermined
height
(13a) for allowing the fluid flow (7) to overflow (exit, release, discharge,
go over, etc.)
CA 02705058 2010-05-20
22
from the accumulation chamber (9). The descent assembly (15), which may take
on
various shapes and forms, as will be explained in greater detail hereinbelow,
is
intended for receiving the fluid flow (7) coming from the accumulation chamber
(9)
via the overflow interface (11), and for allowing said fluid flow (7) to
descend to at
least one lower height (13b) and preferably a plurality or a "cascade" of such
lower
heights 13b), the descent assembly (15) being configured so that residual
flocculating agent from the fluid flow (7) is thereby additionally mixed or
reacted with
mature fine tailings from said fluid flow (7) when the fluid flow (7) is
travelling down
such a descent assembly (15) from an upper region (17a) to a lower region
(17b),
the descent assembly (15) being further configured for preventing overshearing
of
the flocculated mature fine tailings prior to depositing into the deposition
cell.
As mentioned earlier, the descent assembly (15) may take on various suitable
embodiments in order to provide the structural and functional benefits of the
present
invention. Indeed, referring to the general embodiment exemplified in Figures
1-29,
the descent assembly (15) may comprise a cascading assembly (15i) having at
least
one step (19) and at least one corresponding riser (21), for providing a
cascading
effect to the fluid flow (7) trickling down said cascading assembly (15i) so
as to
additionally and gently mix the mature fine tailings with any remaining
residual
flocculating agent in the fluid flow, and/or for further promoting
flocculation of the
already flocculated mature fine tailings in the fluid flow, without causing
overshearing
prior to deposition, which is advantageous for MFT drying purposes, etc.
Indeed, because an objective of the present invention is to provide mixing of
unreacted flocculating agent (i.e. polymer, etc.) while minimizing additional
shear
forces on the existing mixed material, the provision of a cascading assembly
(15i)
with components being adjustable for different types of fluid flows, different
types of
mature fine tailings to be treated, and/or other considerations, provides a
simple, yet
effective solution that enables to overcome various problems associated with
conventional techniques.
CA 02705058 2010-05-20
23
According to a preferred aspect of the present invention, the at least one
step
(19) of the cascading assembly (15i), is wider than the inlet (5), so as to
namely
slowdown the fluid flow (7) as it passes over each step (19) of the deposition
device
(1) so as to help minimize unwanted shear forces. Indeed, because the cascade
box
opens the flow onto steps (19) which are preferably far wider than the feed
pipe (67)
itself, velocity through the cascade box is substantially lower than what the
fluid
would normally see going through an in-line static mixer of the same feed pipe
size.
As a result, fluid shear forces are minimized as the flow passes over the
descent
assembly (15), which in the case of the main preferred embodiment exemplified
in
Figures 1-29, consists of a series of steps (19) and corresponding risers
(21).
Preferably also, and as can be easily understood by a person skilled in the
art, in
view of the present description and the accompanying drawings, each step (19)
and
each riser (21) is configured to be adjustable, or at the very least
interchangeable.
More specifically, and as will be explained in greater detail hereinbelow,
each step
(19) may be adjustable in length, and adjustable in width, and similarly, each
riser
(21) may also be adjustable in height, as well as adjustable in width.
Indeed, although the preferred embodiments of the cascading assembly (15i)
exemplified in Figures 1-29 illustrate variants of the present deposition
device (1)
where each step (19) has a width substantially equal to that of a
corresponding
adjacent riser (21), it is worth mentioning that depending on the particular
applications for which the deposition device (1) is intended for, the desired
end
results and other considerations, each subsequent step (19) could have a shape
and
a dimension being different from that of a preceding step (19), in that each
subsequent step (19) could have, for example, a width or a length being
different
from that of a preceding step (19), in order to further slowdown a fluid flow
(7)
travelling down the cascading assembly (15i). Similar modifications could also
be
made to a given riser (21) with respect to a subsequent or a preceding riser
(21), so
as to adjustably and selectively vary the height of "fall" from one riser (21)
to another.
CA 02705058 2010-05-20
24
According to a particular embodiment of the present invention, each riser (21)
is defined by a corresponding partitioning plate (23) which is preferably
intended to
be removably mountable onto a pair of opposite side walls (25a,25b) of the
deposition device, each slot (27) being defined by a pair of guides (27a,27b),
as can
be easily understood when referring to Figures 1 and 16-18, each partitioning
plate
(23) preferably extending in a substantially traverse manner with respect to
the fluid
flow (7) travelling down the cascading assembly (15i), as better shown in
Figure 1,
for example. However, it is worth mentioning that although the partitioning
plates
(23) shown in the accompanying drawings extend in a substantially traverse
manner
with respect to the fluid flow (7), that is, in a substantially traverse
manner with
respect to a longitudinal axis (51) of the deposition device (1), the
partitioning plates
(23) may be configured so as to be extendable at a given suitable angle with
respect
to the fluid flow (7), or at the very least, with respect to the longitudinal
axis (51) of
the cascading assembly (15i), if deemed appropriate, depending on the desired
end
effects intended with the deposition device (1), as apparent to a person
skilled in the
art. In such a case, instead of having a given partitioning plate (23) being
slidably
insertable into opposite slots (27) of the side walls (25a,25b) of the device
(1), then
either the side edges of the partitioning plates (23) or the corresponding
slots (27)
could be modified so that a first side edge of the partitioning plate (23)
would be
removably insertable into a first given slot (27) on a first given side wall
(25a,25b),
and the opposite side edge of the same partitioning plate (23) would be
removably
insertable into a second slot (27) being at an angle on the opposite side wall
(25b,25a), that is, not oppositely positioned, with respect to the first slot
(27). In such
a case, the kit to be used with the present deposition device (1) could be
provided
with a suitable number of different partitioning plates (23) which could be
interchanged, placed and displaced at different locations of the deposition
device (1)
in order to provide different operating configurations and capabilities for
said
deposition device (1). It is worth mentioning however that various other
suitable
means and dispositions are intended with the present invention so that the
partitioning plates (23) may be positioned either substantially perpendicular
to the
CA 02705058 2010-05-20
longitudinal axis of the deposition device (1), or at an angle with respect
thereto,
depending on the particular applications and the desired end results intended
with
the deposition device (1), as apparent to a person skilled in the art.
In either case, each partitioning plate (23) preferably comprises a
5
reinforcement component, such as an angle bar, as better shown in Figures 16
and
17, for providing structural reinforcement to the partitioning plate (23) in
order to
ensure that the partitioning plate (23) remains in a substantially rectilinear
and un-
deformed configuration. It is worth mentioning, as can also be easily
understood by a
person skilled in the art, that other suitable reinforcement components (ribs,
flanges,
10
etc.) could be used and mounted onto the partitioning plate (23) in order to
provide
such structural reinforcement.
Referring back to Figure 1, there is shown how according to this particular
embodiment of the present invention, the overflow interface (11) simply
consists of
the top edge (31) of an uppermost riser, and as will be explained in greater
detail
15
hereinbelow, the uppermost riser (21) may be either a corresponding
partitioning
plate (23), or an integrated riser (21b) provided by a base (33) portion of
the
deposition device (1). Indeed, according to a preferred embodiment, the
cascading
assembly (15i) is contained within a housing (25) having at least one side
wall
(25a,25b,25c), and a corresponding base (33), as can be easily understood when
20
referring to Figures 1-9. More specifically, and according to the embodiment
shown,
the housing (25) preferably comprises a pair of opposite side walls (25a,25b),
and a
rear end wall (25c), as well as a corresponding base (33) with integrated
components which are securely mounted (ex. welded, bolted, etc.) onto the
housing
(25) in order to form the structural framework of the deposition device (1).
25
Although the following components are not absolutely necessary for a minimal
and proper operation of the present deposition device (1), the base (33) of
the
housing (25) preferably comprises at least one integrated step (19b) and at
least one
CA 02705058 2010-05-20
26
corresponding integrated riser (21b), so as to minimally provide at least one
step
(19) and at least one riser (21) to the deposition device (1), for a minimal
cascading
effect, should no partitioning plates (23) be used, as can be easily
understood by a
person skilled in the art. However, as shown in Figures 1-29, these particular
embodiments of the present invention intend to have at least one partitioning
plate
(23) being removably extendable across at least one integrated step (19b) of
the
base (33) of the housing, and preferably also, said at least one partitioning
plate (23)
is intended to extend along a distal edge of each integrated step (19b).
However, it is
worth mentioning also, that the present invention is not necessarily limited
to the
113 presence of such integrated steps (19b) or risers (21b) provided by the
base (33) of
the housing, and that even in such an event, the present deposition device (1)
is not
limited to the presence of a single partitioning plate (23) per integrated
step (19b).
Indeed, various other alternatives of the present invention may include a
plurality of different partitioning plates (23) being removably extendable
across a
same integrated step (19b) of the base (33) for selectively defining a
plurality of
corresponding sub-steps along said same integrated step (19b). For example,
when
referring to Figure 1, one could easily understand that instead of having a
single pair
of slots (27) disposed at the distal end of the uppermost integrated step
(19b) of the
base (33) of the housing (25), that a suitable number of corresponding slots
(27)
may be provided between said distal edge of such integrated step (19b) and the
uppermost riser (21) shown so as to be capable of receiving either one, or a
plurality
of intermediate partitioning walls (23), which would define corresponding
sub-chambers into which the fluid flow (7) may accumulate, rise, and then
overflow
onto a subsequent sub-chamber downstream (progressive cascading effect, etc.).
Moreover, it could also be easily understood that an upper surface of each sub-
chamber would define a corresponding liquid sub-step (19) for the system.
Indeed, when referring to the accumulation chamber (9) shown in Figure 1 for
example, a person skilled in the art may appreciate that although a first step
(19) is
CA 02705058 2010-05-20
27
not structurally defined by a corresponding physical component, the upper
fluid
surface of the fluid flow (7) accumulated therein, and which overflows over
the top
edge (31) of the uppermost first physical riser (21) could be considered as
being the
very "first" step (19) of the cascading effect provided by the deposition
device (1).
Furthermore, according to the embodiment exemplified, the accumulation
chamber (9) is defined within the housing (25) adjacent to the uppermost riser
(21) of
the deposition device (1), as briefly explained earlier, but it is worth
mentioning also
that other suitable accumulation chambers (9), such as a vertical pipe (55),
or any
other suitable structure where the fluid flow (7) can be substantially reduced
in terms
3.0 of velocity, when received from the inlet (5), and accumulated up to a
desired
starting height, from which a cascading effect can be undertaken, could also
be
appropriate according to the present invention. Moreover, the inlet (5) of the
deposition device (1) is preferably provided with a flange connection (35) for
removably connecting the inlet (5) to a source of fluid flow (7), such a
pressurized
in-line feed coming from a corresponding pipeline, or any other suitable
source of
fluid flow (7), as apparent to a person skilled in the art. As can be easily
understood
by a person skilled in the art, the flange connection (35) at the bottom of
the cascade
box provides the easiest entry point, and although different variations of the
designs
could have the feed pipe entering the top of the cascade box, as exemplified
in
Figures 25-29, this would require additional pipe and fittings.
The present deposition device (1) is preferably manufactured to be
structurally
rigid, and to be able to withstand the different loads and parameters in
cause, and if
need may be, may be provided with at least one reinforcement component (37),
such as a structural crossbar, or any other suitable component which could
provide
structural rigidity to the overall housing structure of the deposition device
(1), as
apparent to a person skilled in the art. Similarly, the deposition device (1),
or at the
very least, its housing (25), preferably comprises at least one lifting
component (39),
such a lifting lug or corresponding bar assembly, as exemplified in Figures 1,
2, 4,
CA 02705058 2010-05-20
28
and 10-14, for allowing the deposition device (1) to be conveniently raised
and
carried over to another location, for corresponding operation. Alternatively,
or in
addition thereto, the deposition device (1) could also be provided with a skid
base
(41), as better shown in Figures 25-28, for allowing the deposition device (1)
to be
dragged from one location to another, as also apparent to a person skilled in
the art.
Indeed, the skid base (41) allows for the cascade box to be dragged around on
site
with ease which is required when using a single cascade box for multiple
deposition
cells. Alternatively, the lifting lugs can also be used at the top of the box
to lift and
move it as needed, instead of dragging. This is likely a most optimal way of
transport, as can be easily understood by a person skilled in the art.
Referring now to the second main preferred embodiment of the present
deposition device (1), as exemplified in Figures 30-48, there is shown how the
descent assembly (15) may consist of a ramp assembly (15ii) having a top
portion
(43) and a bottom portion (45), the ramp assembly (15ii) having a ramp (47)
being
provided with at least one ridge (49) for additional mixing of the mature fine
tailings
with residual flocculating agent as the fluid flow (7) travels down the ramp
(47) and
corresponding ridges (49).
As can be easily understood, each ridge (49) may be disposed in a
substantially traverse manner with respect to a longitudinal axis (51) of the
ramp
(47), but for certain applications, it might be more advantageous to have each
ridge
(49) being disposed at an angle with respect to said longitudinal axis (51).
According
to a preferred embodiment of the present invention, as better shown in Figures
30
and 33, the ramp (47) comprises a plurality of pairs of ridges (49) disposed
crossways with respect to the ramp (47), and each ridge (49) can simply be
defined
by an angle stitch welded onto the ramp. It is worth mentioning also, as can
be easily
understood by a person skilled in the art, that other suitable dispositions,
geometric
configurations, components to be used for defining the ridges (49), are
intended
according to the present invention. For example, the expression "ridge" (49)
is not
CA 02705058 2010-05-20
29
intended to be interpreted in a restrictive way (i.e. protruding, etc.), and
may include
a given "recess" with which the fluid flow (7) may operate, in order to obtain
desired
end results. Indeed, instead of having corresponding ridges (49), one could
provide
a plurality of corresponding longitudinal recesses disposed about the ramp
(47)
where fluid flow (7) traveling down said ramp (47) would cooperate with such
recesses which would provide the mixing of flocculated MFT with the polymer
without overshearing, etc.
Figures 44-48 exemplify how the ramp assembly (15ii) according to a
preferred embodiment of the present invention is tapered, the bottom portion
(45)
being wider than the top portion (43), namely so as to further reduce the flow
velocity
of the fluid flow (7), so as to provide an ideal mixing of un-reacted
flocculating agent
with the mature fine tailings while minimizing additional shear forces on the
existing
mixed material, as explained earlier. Preferably, the ramp assembly (15ii) is
provided
with a pair of containment walls (53) for containing the fluid flow (7) above
the ramp,
and between said containment walls (53), as better shown in Figures 44 and 47.
However, as can be easily understood by a person skilled in the art, other
suitable
dispositions could be used for guiding the fluid flow (7) down along the ramp
assembly (15ii).
According to this main second preferred embodiment of the deposition device
(1), the accumulation chamber (9) is preferably a vertical pipe (55), as
exemplified in
Figures 30-38, the vertical pipe (55) having a diameter which is bigger than
the
diameter of its corresponding inlet (5). Preferably also, the top portion (43)
of the
ramp assembly (15ii) is removably connectable to the overflow interface (11)
of the
device (1), and such an overflow surface (11) is provided by an upper cut-out
portion
(57) of the vertical pipe (55), the upper cut-out portion (57) of the vertical
pipe (55)
being preferably provided with a spill box (59), as better shown in Figures 39-
43.
CA 02705058 2010-05-20
Preferably also, the spill box (59) comprises a pin (61), and a top portion
(43)
of the ramp assembly (1511) comprises a corresponding hole (63), said hole
(63)
being insertable about the pin (61) for removably connecting the ramp assembly
(15ii) onto the spill box (59), as can be understood when referring to Figures
30-33
5 and 39-46. Preferably also, the spill box (59) may further comprise a
bottom
abutment flange (65) for abutting against a peripheral surface of the vertical
pipe
(55) when the spill box (59) is mounted onto the upper cut-out portion (57) of
the
vertical pipe (55), for providing additional stability to the overall design
of the
deposition device (1). As can be easily understood by a person skilled in the
art,
10 aside from the components that are intended to be removably connectable
onto one
another, other suitable components of the deposition device (1) according to
this
particular embodiment could be suitably connected onto one another, via
appropriate
affixing means, such as welding, bolting, and the like.
The inlet (5) of the deposition device (1) according to this particular
15 embodiment is preferably provided on a bottom portion (45) of the
vertical pipe and
provided by a feed pipe (67) mountable to said bottom portion (45) of the
vertical
pipe (55), the feed pipe (67) being fluidly connected to an inside portion of
the
vertical pipe (55) for feeding the vertical pipe (55) with fluid flow (7), and
the feed
pipe (67) being further fluidly connectable to a pipeline carrying the fluid
flow (7). As
20 may be appreciated, the bottom portion (45) of the vertical pipe (55) is
preferably
provided with at least one support (71), for providing a corresponding support
to the
overall deposition device (1), and according to the embodiment illustrated in
the
accompanying drawings, the at least one support (71) preferably comprises at
least
one supporting pipe (71), and preferably, three such supporting pipes (71)
disposed
25 in an equally spaced manner about the vertical pipe (55) along with the
feed pipe
(67). However, it is worth mentioning that other suitable means could be used
for
providing a corresponding support (71) to the vertical pipe (55), and thus to
the slide
deposition device (1), such as, for example, a corresponding plate, whether
rectangular, circular or the like, which could be welded onto a bottom end of
the
CA 02705058 2010-05-20
31
vertical pipe (55). According to the embodiment illustrated in the
accompanying
drawings, each supporting pipe (71) which is preferably welded on to a bottom
portion of the vertical pipe (55) is closed ended, so that no fluid flow (7)
enters into
any of the supporting pipes (71), therefore, a fluid connection is only
preferably
provided between the feed pipe (67) and the inside portion of the vertical
pipe (55).
It may now be better appreciated that various different types of embodiments
may be used for the different components and features of the present
invention. For
example, when referring to the third main preferred embodiment of the
deposition
device (1) illustrated in Figures 49-51 for example, there is shown how the
accumulation chamber (9) may consist of a vertical pipe (55) and where the
overflow
interface (11) may simply consist of at least one aperture (73) defined about
the
vertical pipe (55), at suitable locations around said vertical pipe (55). More
specifically, according to this embodiment, there is a plurality of apertures
(73) at
different heights, levels, offsets and angles of the vertical pipe (55), and
preferably,
there is a given set of apertures (73) for each level, so that, a minimal
amount of two
sets of apertures (73a,73b) are required for carrying out a corresponding
descent
assembly (15), the first set being lower than the second set, and spaced apart
such
that fluid flow (7) is spilled out of the first set until mature accumulates
above the first
set sufficient to block the first set of apertures (73a) and cause the fluid
flow (7) to
flow upward the vertical pipe to the second set to be spilled out from said
second set
of apertures (73b), as can be easily understood by a person skilled in the
art.
Therefore, one may now better appreciate that, according to the present
invention, the descent assembly (15), corresponding structural and functional
features, and resulting advantages, may consist of different alternatives,
depending
on the particular applications for which the present deposition device (1) is
intended
for, and the desired end results, as well as the degree of sophistication with
which
the mature fine tailings is to be treated, and the adaptability and/or the
adjustability
of the deposition device (1) being desired, as apparent to a person skilled in
the art.
CA 02705058 2010-05-20
32
According to the present invention, the deposition device (1) and
corresponding parts are preferably made of substantially rigid materials, such
as
metallic materials (stainless steel, etc.), hardened polymers, composite
materials,
and/or the like, whereas other components thereof according to the present
invention, in order to achieve the resulting advantages briefly discussed
herein, may
preferably be made of a suitably malleable and resilient material, such as a
polymeric material (plastic, rubber, etc.), and/or the like, depending on the
particular
applications for which the deposition device (1) and resulting pipeline,
fitting or
deposition cell are intended for and the different parameters in cause, as
apparent to
1.0 a person skilled in the art.
It may now also be better appreciated how the present invention is a
substantial improvement over the prior art in that, by virtue of its design
and
components, the deposition device (1) is simple and easy to use, as well as
simple
and easy to manufacture and/or assemble, and provide for a much more simple
and
cost effective manner of processing MFT, namely in order to recover flocculent
agent
not having been used and/or in order to aid in the water release of the
flocculated
mature fine tailings before deposition, for improving MFT drying purposes,
etc.
Indeed, it is well known in the art that flocculated MFT is typically fed into
a
deposition cell via a pipeline. Very often, extra mixing of the fluid is
required to bring
the material to the optimal point for water release and subsequent drying
time,
Instead of having typical in-line mixing devices which introduce high amounts
of
shear force which in turn break up the flocculated MFT in their attempt to
provide
mixing, which is disadvantageous for obvious reasons known in the art, the
present
deposition device (1), such as for example, as cascade box, is placed at the
head
end of the drying cell with the feed pipe entering the lower back side of the
box, in
order to overcome several of the disadvantages associated with the prior art.
Typically, and as explained herein, fluid fills the back chamber of the box
thus
elevating the fluid to the first cascade step, which is approximately six feet
in height,
CA 02705058 2010-05-20
33
the fluid then, by force of gravity, spills over a series of steps set to a
predetermined
height. As the fluid passes over each step, gentle mixing of the fluid is
achieved until
it flows out of the bottom and into the deposition cell.
Thus, the present deposition method and corresponding deposition devices
(1) provide an ideal balance when mixing un-reacted polymer with mature fine
tailings while minimizing additional shear forces on the existing mixed
material. Tests
having been carried out have shown to provide an improved mixing of
flocculated
MFT while minimizing shear forces. This is believed to be due to the design of
the
deposition device (1) (for example, the cascade box, etc.) which opens the
flow to
1.0 atmosphere and allows the fluid to flow over a series of steps (19) by
force of gravity.
This is a much more different approach than what is done with a typical mixer
which
is done in-line and under pressure at much higher velocities. In contrast, the
present
invention not only enables for a gentle mixing while minimizing shear forces,
but
after the last step (19) in the cascade box, the flocculated MFT flows
directly into the
deposition cell, helping to control flow into the cell and also to avoid high
velocity
discharges which would normally add more shear forces and potential safety
hazards.
The present invention is also advantageous in that because according to a
given embodiment, namely the cascade box, the deposition device (1) opens the
flow onto steps (19) which are far wider than the feed pipe (67) itself,
velocity
through the cascade box is substantially lower than what the fluid would
normally
see going through an in-line static mixer of the same feed pipe size. As a
result and
as previously explained, fluid shear forces are minimized as the flow passes
over the
descent assembly (15), which according to the embodiments illustrated in
Figures 1-
29 for example, take the form of steps (19) in a cascading box. Because the
material
will have the proper mixing and the flocculation is optimized, the deposition
is set up
for maximum water release and subsequent minimal drying time, one of the key
performance indicators for tailings reduction operations. The present
invention is
CA 02705058 2010-05-20
34
also advantageous in that by virtue of its design and components, the
deposition
device (1) enables excess and un-mixed polymer (due to inefficient injection
into the
fluid flow, etc.), to be re-introduced into the stream thus creating the
greatest
potential for MFT drying.
The present invention is also advantageous in that, as previously explained
hereinabove, the deposition device (1) comprises components and means for
implementing some adjustability in the number of steps (19) and risers (21)
for a
given scenario, and also for varying the spatial and dimensional
characteristics of
these steps (19) and risers (21), as explained earlier. For example, if only
minimal
mixing is required, then one can only use a single step (19), whereas if for a
given
fluid, due to process parameters, this requires a large amount of mixing, then
one
could use several or all of the steps (19) attainable or possible with the
present
deposition device (1), for obtaining maximum mixing.
As also briefly outlined above, the present invention is also advantageous in
that the deposition device (1) provides mobility, being able to be picked up
and
moved around for transport or drainage purposes via its lifting components
(39), or
skid base (41), which is always very beneficial for operations and maintenance
staff.
The present invention is also advantageous in that the feed connection point,
which
is preferably a flange connection (35) at the bottom of the cascade box for
example,
provides an easy connection, particularly for tailings reductions operations
where
assets are continually being relocated. The width of the steps (19) also
ensures that
this lowers the velocity of the fluid and provides a gentle cascading effect
where fluid
shear is minimized. The fact that the steps (19) may be removable, in the
event that
the steps (19) are too high, or that a suitable number of steps (19) need to
be
changed, it is also advantageous in that the steps (19) and risers (21) can be
removed and replaced with different types of steps (19) and risers (21) if
deemed
necessary, or replaced by another suitable number of steps (19) and/or risers
(21),
as explained earlier.
CA 02705058 2010-05-20
Furthermore, it is worth mentioning that if need may be, the deposition device
(1) may be configured so as to be provided with proper drainage means for
allowing
remaining fluid flow (7) inside the deposition device (1) to be evacuated. For
example, the embodiment of the deposition device (1) illustrated in Figure 1,
that is,
5 the cascade box, may be simply tilted about 90 degrees forward by a loader
using
the lifting lugs and a sling in order to drain the fluid out of the front, for
example.
Alternatively, or in addition thereto, the system could also be modified so as
to add a
large drain on the feed line just before entering the box. Another solution
could
simply involve an access hatch near the bottom that would offer a large
opening for
10 fluid to drain. Yet another solution would be to have at least one
drainage hole (23a)
on a bottom portion of each partitioning plate (23), as exemplified in Figure
17 for
example, so that if no new feed of fluid flow (7) is brought to the deposition
device
(1), then any remaining fluid flow (7) inside the deposition device (1) could
drain
naturally by gravity by passing through the drainage hole (23a) of each
partitioning
15 plate (23), as can be easily understood by a person skilled in the art.
Of course, numerous modifications could be made to the above-described
embodiments without departing from the scope of the invention, as defined in
the
appended claims.
