Note: Descriptions are shown in the official language in which they were submitted.
CA 02948019 2016-11-08
AUTOMATED METHYLENE BLUE INDEX ANALYSIS OF MATURE FINE TAILINGS
TECHNICAL FIELD
[0001] The technical field generally relates to automated methylene blue
index (MBI)
analysis of mature fine tailings (MFT), and more particularly in the context
of MFT
flocculation and dewatering operations.
BACKGROUND
[0002] Tailings derived from mining operations, such as oil sands mining,
are often
placed in dedicated disposal ponds for settling. The settling of fine solids
from the water
in tailings ponds is a relatively slow process. Over time, a layer of mature
fine tailings
(MET) having relatively high solids and clay content can form in the pond. MFT
has slow
consolidation rates and can be challenging to dewater.
[0003] Some techniques have been developed for treating MFT. For example,
MFT
can be retrieved from the pond and subjected to flocculation followed by sub-
aerial
deposition for dewatering. The flocculant added to the MFT can be doses on a
clay basis
to enhance performance of the dewatering process. Measuring clay content of
the MFT
can be a useful step on which to base flocculant dosage.
[0004] Methylene blue index (M131) is a titration test result that can be
useful as an
indication of clay content or activity in a sample. MBI has been used to
provide
information about certain clay-containing materials.
SUMMARY
[0005] In some implementations, there is provided an automated methylene
blue
index (MBI) analyzer for analyzing mature fine tailings (MFT) samples,
comprising: a
sample holder configured to receive and hold the MFT sample; a methylene blue
(MB)
container configured to receive and contain MB; an addition mechanism for
adding MB
increments obtained from the MB container into the sample holder to produce an
MB-
MFT titration sample; a mixer for mixing the MB-MFT titration sample; a
dispenser for
dispensing a drop of the MB-MFT titration sample; an absorbent material
arranged with
respect to the dispenser to receive the drop of the MB-MFT titration sample
from the
dispenser, to form a spot on the absorbent material; a digital camera
positioned relative
CA 02948019 2016-11-08
2
to the absorbent material and configured to acquire a digital image of the
spot, the digital
image comprising color properties including hue and chroma; and an image
processor
coupled to the digital camera and configured to: receive the digital image of
the spot;
determine hue and chroma of a central region of the spot, an outer dye region
of the
spot, a water mark region and a background region; identify transition points
of the hue
and chroma between the central region of the spot and the outer dye region of
the spot,
between the outer dye region of the spot and the water mark region, and
between the
water mark region and the background region; determine transition point values
for each
of the identified transition points; compare the transition point values with
corresponding
calibration values; provide a signal to continue MB titration of the MFT
sample if the
transition point values do not substantially match the calibration values; and
provide a
signal to cease MB titration of the MFT sample if the transition point values
substantially
match the calibration values which indicates that the titration is complete,
thereby
providing MBI data for the MFT sample.
[0006] In some
implementations, there is provided an automated methylene blue
index (MBI) analyzer for analyzing mature fine tailings (MFT) samples,
comprising: a
sample holder configured to receive and hold the MFT sample; a methylene blue
(MB)
container configured to receive and contain MB; an addition mechanism for
adding MB
increments obtained from the MB container into the sample holder to produce an
MB-
MFT titration sample; a mixer for mixing the MB-MFT titration sample; a
dispenser for
dispensing a drop of the MB-MFT titration sample; an absorbent material
arranged with
respect to the dispenser to receive the drop of the MB-MFT titration sample
from the
dispenser, to form a spot on the absorbent material; a digital camera
positioned relative
to the absorbent material and configured to acquire a digital image of the
spot, the digital
image comprising color properties; and an image processor coupled to the
digital
camera and configured to: receive the digital image of the spot; determine
color
properties of a central region of the spot, an outer dye region of the spot, a
water mark
region and a background region; identify transition points of the color
properties between
the central region of the spot and the outer dye region of the spot, between
the outer dye
region of the spot and the water mark region, and between the water mark
region and
the background region; determine a first value for the transition point
between central
region of the spot and the outer dye region of the spot, a second value for
the transition
point between the outer dye region of the spot and the water mark region, and
a third
CA 02948019 2016-11-08
3
value for the transition point between the water mark region and the
background region;
average the first and second values to produce a first averaged value, and
compare the
first averaged value with a corresponding first calibration value; average the
second and
third values to produce a second averaged value, and compare the second
averaged
value with a corresponding second calibration value; generate a signal to
cease the MB
titration if the first and second averaged values substantially match the
corresponding
first and second calibration values; and generate a signal to continue MB
titration of the
MFT sample if the first and second averaged values do not substantially match
the
corresponding first and second calibration values.
[0007] In some implementations, there is provided an automated methylene
blue
index (MBI) analyzer for analyzing mature fine tailings (MFT) samples,
comprising: a
sample holder configured to receive and hold the MFT sample; a methylene blue
(MB)
container configured to receive and contain MB; an addition mechanism for
adding MB
increments obtained from the MB container into the sample holder to produce an
MB-
MFT titration sample; a mixer for mixing the MB-MFT titration sample; a
dispenser for
dispensing a drop of the MB-MFT titration sample; an absorbent material
arranged with
respect to the dispenser to receive the drop of the MB-MFT titration sample
from the
dispenser, to form a spot on the absorbent material; a digital camera
positioned relative
to the absorbent material and configured to acquire a digital image of the
spot; and an
image processor coupled to the digital camera and configured to receive the
digital
image of the spot, determine whether titration is complete, and provide a
signal to cease
or continue MB titration of the MFT sample, thereby providing MBI data for the
MFT
sample.
[0008] In some implementations, the sample holder comprises a cup, a vial
or a
sealed vessel. In some implementations, the sample holder is configured to
receive the
MFT sample from a pipeline flow of the MFT. In some implementations, the
sample
holder is configured to receive the MFT sample from a tailings pond. In some
implementations, the MB container comprises a cup or a sealed vessel.
[0009] In some implementations, the addition mechanism comprises a robotic
arm
configured to engage the MB container and to dispense the MB increment from
the MB
container into the sample holder. In some implementations, the addition
mechanism
comprises an MB titration line in fluid communication between the MB container
and the
CA 02948019 2016-11-08
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sample holder to provide flow of the MB increment into the sample holder. In
some
implementations, the addition mechanism further comprises pump coupled to the
MB
titration line for pumping the MB increment there through. In some
implementations, the
MB container is positioned above the sample holder to enable gravity to induce
the flow
of the MB increment into the sample holder. In some implementations, the
addition
mechanism further comprises an MB valve disposed on the MB titration line.
[0010] In some implementations, the mixer is configured to engage with the
sample
holder to provide pre-titration mixing to the MFT sample. In some
implementations, the
mixer comprises a robotic arm configured to engage the sample holder and
provide
mixing energy to the MFT sample.
[0011] In some implementations, the analyser includes a sonication unit
configured
to provide sonication to the MFT sample prior to titration. In some
implementations, the
sonication unit is configured to engage the sample holder to provide the
sonication to the
MFT sample within the sample holder.
[0012] In some implementations, the analyser includes a heater configured
to
provide heating to the MFT sample prior to titration. In some implementations,
the heater
is configured to engage the sample holder to provide the heating to the MFT
sample
within the sample holder.
[0013] In some implementations, the dispenser comprises a syringe. In some
implementations, the dispenser is configured to be engaged by a robotic arm in
order to
retrieve a portion of the MB-MFT titration sample from the sample holder and
then
dispense the drop onto the absorbent material.
[0014] In some implementations, absorbent material comprises filter paper.
In some
implementations, the filter paper comprises a strip of filter paper dispensed
from a roll
mounted to a spool and being rotatable to provide fresh sections of the filter
paper below
the dispenser for receiving respective drops; or wherein the filter paper
comprises a
circular disk-shaped paper that is rotatable to provide fresh sections of the
circular disk-
shaped paper below the dispenser for receiving respective drops.
CA 02948019 2016-11-08
[0015] In some implementations, the digital camera is positioned and
oriented to
capture the digital image of the spot moving the absorbent material from a
location
where the spot was initially formed.
[0016] In some implementations, the analyzer includes a light source for
illuminating
the spot for the digital camera. In some implementations, the light source is
configured to
illuminate each spot so that the digital image of each spot has a generally
constant
lightness. In some implementations, the light source comprises a camera flash
unit.
[0017] In some implementations, the camera is configured such that the
digital
image of the spot includes color properties comprising at least hue and
chroma.
[0018] In some implementations, the image processor is configured to
determine the
hue and chroma of a central region of the spot, an outer dye region of the
spot, a water
mark region and a background region. In some implementations, the image
processor is
configured to identify transition points of the color properties between the
central region
of the spot and the outer dye region of the spot, between the outer dye region
of the spot
and the water mark region, and between the water mark region and the
background
region. In some implementations, the image processor is configured to identify
the
transition points based on inflection points of the color properties. In some
implementations, the image processor is configured to identify the transition
points along
an x-axis and a y-axis from a center of the spot.
[0019] In some implementations, the image processor is configured to
compare the
transition points with corresponding calibration values, and to determine
whether titration
is complete based on such comparison. In some implementations, the image
processor
is configured to determine a first value for the transition point between
central region of
the spot and the outer dye region of the spot, a second value for the
transition point
between the outer dye region of the spot and the water mark region. In some
implementations, the image processor is configured to average the first and
second
values, and compare the averaged value with a corresponding calibration value.
In some
implementations, the image processor is configured to determine a third value
for the
transition point between the water mark region and the background region. In
some
implementations, the image processor is configured to average the second and
third
values, and compare the averaged value with a corresponding calibration value.
In some
CA 02948019 2016-11-08
6
implementations, the image processor is configured to generate a signal to
cease the
MB titration if the averaged values substantially match the corresponding
calibration
values.
[0020] In some implementations, the image processor is configured to
generate a
signal to pause to allow drying of the spot, so that a dry-spot digital image
is acquired
and processed. In some implementations, the image processor is configured to
analyse
the dry-spot digital image in according to a corresponding methodology as the
spot, and
to generate a signal to cease the MB titration if the averaged values for the
dry-spot
digital image substantially match the corresponding calibration values.
[0021] In some implementations, the analyzer also includes a controller for
controlling at least one of the following: quantity of each MB increment that
is supplied
from the MB container to the sample holder; activation and energy of the
mixer;
activation of the dispenser; location of the absorbent material relative to
the dispenser;
activation of the digital camera; activation of each round of the titration
based on the
signal generated by the image processor; cessation of the titration based on
the signal
generated by the image processor; and coordination of movement and timing of
components and fluids.
[0022] In some implementations, the analyzer also includes at least one
robotic arm
configured to manipulate the sample holder, the MB container, the addition
mechanism,
the mixer, the dispenser, the absorbent material, the digital camera, and/or
the image
processor; and/or to act as the mixer, the addition mechanism and/or the
dispenser.
[0023] In some implementations, the analyzer also includes a transmitter
configured
to receive the MBI data from the image processor, and to transmit the MBI data
to a
receiver that is part of a downstream system.
[0024] In some implementations, the downstream system comprises an MET
flocculation unit and the MBI data is transmitted to a flocculent injector.
[0025] In some implementations, the analyzer also includes a support frame
that is
relocatable to at-line positions along an MET pipeline.
[0026] In some implementations, there is provided a system for dewatering
mature
fine tailings (MET), comprising: a flocculent addition unit for adding
flocculent into the
CA 02948019 2016-11-08
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MFT on a clay basis to produce flocculated tailings; a dewatering unit
receiving the
flocculated tailings; and the automated MBI analyzer as defined or described
herein,
configured to receive MFT samples upstream of the flocculant addition unit;
wherein the
flocculation addition unit is controlled at least in part based on the MBI
data generated
by the automated MBI analyzer.
[0027] In some implementations, there is provided method for dewatering
mature
fine tailings (MFT), comprising: adding floccuant to the MFT according to a
clay-based
dosage to produce flocculated tailings; dewatering the flocculated tailings;
adjusting the
clay-based dosage based on MBI data generated by the automated MBI analyzer as
defined or described herein.
[0028] In some implementations, there is provided an automated methylene
blue
index (MBI) analyzer for analyzing clay-containing samples, comprising: a
sample holder
configured to receive and hold the clay-containing samples; a methylene blue
(MB)
container configured to receive and contain MB; an addition mechanism for
adding MB
increments obtained from the MB container into the sample holder to produce a
titration
sample; a mixer for mixing the titration sample; a dispenser for dispensing a
drop of the
titration sample; an absorbent material arranged with respect to the dispenser
to receive
the drop of the titration sample from the dispenser, to form a spot on the
absorbent
material; a digital camera positioned relative to the absorbent material and
configured to
acquire a digital image of the spot; and an image processor coupled to the
digital
camera and configured to receive the digital image of the spot, determine
whether
titration is complete, and provide a signal to cease or continue MB titration
of the clay-
containing sample, thereby providing MBI data for the clay-containing samples.
[0029] It should be noted that the analyzer for analyzing clay-containing
samples
can have one or more features as described or defined herein.
[0030] In some implementations, there is provided automated methylene blue
index
(MBI) analysis method for analyzing clay-containing samples, comprising:
subjecting a clay-containing sample to automated methylene blue (MB)
titration,
comprising:
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adding MB increments into the sample holder to produce a titration
sample;
mixing the titration sample;
dispensing a drop of the titration sample onto an absorbent material to
form a spot; and
assessing color properties of the spot to evaluate the titration, wherein
assessing the color properties comprises:
acquiring a digital image of the spot; and
processing the digital image of the spot to determine whether
titration is complete; and
providing a signal to cease or continue MB titration of the clay-containing
sample.
[0031] In some implementations, there is provided a system for dewatering a
clay-
containing aqueous material, comprising: a flocculant addition unit for adding
flocculant
into the clay-containing aqueous material on a clay basis to produce
flocculated tailings;
a dewatering unit receiving the flocculated tailings; and the automated MBI
analyzer as
defined or described herein, configured to receive clay-containing samples
upstream of
the flocculant addition unit; wherein the flocculation addition unit is
controlled at least in
part based on the MBI data generated by the automated MBI analyzer.
[0032] In some implementations, there is provided a method for dewatering a
clay-
containing aqueous material, comprising: adding floccuant to the clay-
containing
aqueous material according to a clay-based dosage to produce flocculated
tailings;
dewatering the flocculated tailings; adjusting the clay-based dosage based on
MBI data
generated by the automated MBI analyzer as defined or described herein.
[0033] Implementations of the automated MBI analyzer and associated methods
can
provide various advantages, some of which are the following: increasing
repeatability
and reliability of results compared to manual methods; accelerating titration
procedures
to obtain results more rapidly; reducing intervention by operators to limit
operator-
sensitivity and labour involved; and enhancing input of MBI data into the
flocculation and
9
dewatering process which can reduce flocculant usage and improve dewatering
efficiency.
[0033a] In some implementations, there is provided an automated fluid
analyzer for
analyzing fluid samples, comprising:
a sample holder configured to receive and hold the fluid samples;
a container configured to receive and contain a titration compound;
an addition mechanism for adding increments of the titration compound
obtained from the container into the sample holder to produce a titration
sample;
a mixer for mixing the titration sample;
a dispenser for dispensing a drop of the titration sample;
an absorbent material arranged with respect to the dispenser to receive the
drop of the titration sample from the dispenser, to form a spot on the
absorbent material;
a sensor positioned in spaced-apart relation relative to the absorbent
material and configured to acquire digital information regarding the spot;
and
a processor coupled to the sensor and configured to receive the digital
information regarding the spot, determine whether titration is complete, and
provide a signal to cease or continue titration of the fluid sample, thereby
providing titration data for the fluid samples.
[0033b] In some implementations, there is provided an automated fluid
analysis
method for analyzing fluid samples, comprising:
subjecting a fluid sample to automated titration, comprising:
adding increments of a titration compound into a sample holder to produce
a titration sample;
Date Recue/Date Received 2021-06-23
9a
mixing the titration sample;
dispensing a drop of the titration sample onto an absorbent material to form
a spot;
acquiring digital light-based information regarding the spot; and
processing the digital light-based information regarding the spot to
determine whether titration is complete; and
providing a signal to cease or continue the titration of the fluid sample.
[0033c] In some implementations, there is provided a system for
dewatering a
slurry material, comprising:
a flocculant addition unit for adding flocculant into the slurry material
produce flocculated tailings;
a dewatering unit receiving the flocculated tailings; and
the automated fluid analyzer as defined herein, configured to receive slurry
samples upstream of the flocculant addition unit;
wherein the flocculation addition unit is controlled at least in part based on
data generated by the automated fluid analyzer.
[0033d] In some implementations, there is provided a method for
dewatering a
slurry material, comprising:
adding flocculant to the slurry material to produce flocculated tailings;
dewatering the flocculated tailings; and
adjusting a dosage of the flocculant based on data generated by the
automated fluid analyzer as defined herein, or based on data generated by
the automated fluid analysis method as defined herein.
Date Recue/Date Received 2021-06-23
9b
BRIEF DESCRIPTION OF DRAWINGS
[0034] Fig 1 is a process flow diagram showing an MFT dewatering
operation.
[0035] Fig 2 is a process flow diagram showing an MBI analyzer for
analyzing MFT.
[0036] Fig 3 is a process flow diagram showing two potential locations for
an MBI
analyzer.
[0037] Fig 4 illustrates steps for automated MBI analysis of MFT.
[0038] Fig 5 is a schematic of an MBI analysis system.
[0039] Fig 6 is a schematic illustrating digital spot images.
[0040] Fig 7 is a process flow diagram showing MBI analyzers and multiple
tailings
ponds.
[0041] Fig 8 is a process flow diagram showing MBI analyzers and multiple
tailings
pipelines.
[0042] Fig 9 is a process flow diagram showing an MBI analyzer and
multiple tailings
pipelines.
[0043] Fig 10 is a schematic of an MBI analyzer that is at-line and
upstream of a
flocculant injection unit.
DETAILED DESCRIPTION
[0044] Automated MBI analysis of MFT samples facilitates enhanced
reliability,
consistency and speed in acquiring MBI data that can be used to provide
information for
an MFT flocculation and dewatering operation, such as informing clay-based
dosage of
flocculant added to the MFT.
Date Recue/Date Received 2021-03-17
CA 02948019 2016-11-08
General process overview and implementations
[0045] Referring to Fig 1, an MFT dewatering operation 10 can include an
MFT
source 12, such as a tailings pond, from which MFT is retrieved as an in-line
MFT
flow 14. The MFT flow 14 can then be supplied to one or more pre-treatment
units (not
shown) to produce a pretreated MFT stream. The pre-treatment units can include
various different units for screening, diluting, pre-shearing and/or
chemically pre-treating
the MFT. The MFT stream 14 is then supplied to a flocculant injection unit 16
for
injecting a flocculant stream 18 into the tailings. The resulting flocculation
material 20
can then be subjected to conditioning, which may include pipeline shear
conditioning, to
form a conditioned material. The conditioned material is then sent to a
dewatering
unit 22, which may for example be a sub-aerial deposition area, a dewatering
device, or
an aquatic storage structure. Release water 24 separates from solids-enriched
flocculated material 26 and can be used a recycled water for addition to
certain pre-
treatment units, the flocculant stream, or other unit operations in the
associated mining
facility.
[0046] Fig 1 also illustrates that the MFT can be monitored using an
automated MBI
analyzer 28. The automated MBI analyzer 28 can determine MBI data from MFT
samples 30 that are obtained from the MFT in-line flow 14, from a holding
tank, and/or
from the tailings pond. The MBI data obtained from the automated MBI analyzer
28 can
then be used to control one or more unit operations. For example, flocculant
dosage is a
relevant parameter for enabling consistent and efficient performance of the
flocculation
and dewatering of the MFT. Process parameters, such as flocculant
concentration in the
flocculant stream 18 and the composition of the MFT stream 14 supplied to the
injector 16, are relevant to flocculant dosage and thus can be controlled
based on the
MBI data to provide a desired clay-based flocculant dosage.
[0047] Fig 2 illustrates a scenario where the automated MBI analyzer 28
obtains a
sample from a tank 32, and Fig 3 illustrates the scenario where two automated
MBI
analyzers 28A, 28B obtains samples from different points in the process. Fig 3
in
particular illustrates that the automated MBI analyzers can be provided on
upstream and
downstream sides of a pre-treatment unit 34 (e.g., dilution unit or another
unit that may
impact the active clay content of the MFT) to obtain MBI data for the input
MFT 14 and
the pre-treated MFT 36. Various other configurations are possible where
multiple
CA 02948019 2016-11-08
11
automated MBI analyzers 28 are provided at different locations in the process
upstream
of the flocculant injector.
[0048] Automated MBI analysis of MFT samples can be particularly
advantageous in
the context of flocculating the MFT. As MFT that is, for example, retrieved
from a pond
or another source can have a variable composition including clay content and
the clays
in MFT have an impact on the flocculation process, MBI data can be used as an
input
variable to enhance flocculation. Control of polymer flocculant dosing into
thick fine
tailings (e.g., MFT) is advantageously done on a clay basis, and thus the MBI
of the
tailings can provide a useful input for controlling flocculation. Manual
methods for
acquiring MBI are time consuming and labor intensive and as such cannot easily
be
implemented at-line for process control, thus reducing the operational
efficiency of
tailings flocculation and dewatering operations. The automated MBI analyzer
instrument
can facilitate the capability to control polymer flocculant dosing in
flocculation and
dewatering operations, by providing reliable and rapid analysis that can be
conducted at-
line of the tailings pipeline which transports the tailings from the source
(e.g., pond) to
the flocculation and dewatering operations.
[0049] MBI testing determines the capacity of clay to absorb cations from a
solution,
and therefore provides an indication of the clay activity. Clays are found in
a variety of
materials and fluids, including drilling fluids, fracking fluids, binder
materials, and a
number of mining streams (e.g., mined ore, slurries, underflows, overflows,
middlings,
and various tailings or byproduct streams) and in situ recovery streams or
materials
(e.g., production fluid, oil and water streams which are separated at surface,
core
samples, and blowdown streams from OTSGs or evaporators). The MBI test is
based on
the cation-exchange capacity of clays, which can vary depending on the type of
clay.
MBI is thus an estimate of cation exchange capacity (CEC), although MB
capacity and
CEC are not equivalent with MB capacity being typically less than CEC. The
reactive or
active component of the clays that are involved in cation exchange in the
context of the
MBI test. The active clay particles/sheets which are negatively charged are
coated with
the cationic MB dye molecules, which results in a distinct dark blueish color
until cation
exchange capacity has been reached. Once the cation exchange capacity has been
reached, excess MB that is not bound to clay remains in solution and results
in a blue-
green color that forms a "halo" around the dark blueish spot. Formation of a
persistent
blue-green halo indicates that the clays have reached their absorption
capacity of the
CA 02948019 2016-11-08
12
MB dye. The MB titration is thus complete and the MBI value can be calculated
as
follows:
(meg \ ,mls MB x Normality of MB
Mal __________________________________________ X100
100g) mass of dried sample (g)
[0050] In the above equation, "mls MB" is the volume of MB used in the
titration in
milliliters; Normality of MB is the concentration of the MB solution used
(e.g., typically
0.006 M); and the units of MBI are milliquivalents (mEq) per 100 g of solids.
[0051] Other clay-related properties can be calculated based, in part, on
MBI. For
example, surface area of clay particles and weight percentage of clay can be
calculated based on certain equations. For example, an equation to estimate
surface
area of clay particles is:
( 7712 \
Sur face Area ¨ = 14131 X 130 X 0.06022
g 1
[0052] An equation to estimate weight percentage of clay is:
rraLs MB X 0.006 N 0.04
Wt% Clay¨ _____________________________________ X100
14
[0053] It should be noted that the MBI values can be used directly in
process
control and/or can be used to compute or estimate other properties of the MFT
in
order to generate variables (e.g., wt% clay, clay surface area) that can be
used for
process control and/or assessment.
Automated MBI analyzer implementations
[0054] Referring to Fig 5, the automated MBI analyzer 28 can include
several
components for automatically titrating MFT samples using image acquisition and
processing to provide consistent and rapid MBI data.
CA 02948019 2016-11-08
13
[0055] Fig 5 illustrates that the automated MBI analyzer 28 includes a
sample
holder 38 which receives the MFT sample 30. The sample holder may be a
container
that may be sealable or open. There may be multiple sample holders for holding
multiple
samples, dividing a primary sample into multiple sub-samples, and/or
transferring a
sample to different holders, if desired. The sample holder can include
measurement
indicia (e.g., for volume) and may be composed of glass or another transparent
material.
[0056] The automated MBI analyzer 28 also includes a mixer 40 that is
adapted to
engage the sample holder 38 in order to mix the sample and contribute to
dispersion of
the clays throughout the sample. Dispersion is an important factor in
obtaining accurate
MBI data. The mixer 40 may include an agitator that is insertable within the
sample
holder 38 and/or a shaking mechanism that grasps the sealed sample holder and
provides back-and-forth movement in order to mix the MFT sample. The mixer 40
can be
configured and operated in order to provide a pre-determined mixing time and
energy to
fully disperse the clays.
[0057] The automated MBI analyzer 28 can also include additional components
to
contribute to dispersion of the clays throughout the sample. For example, the
automated
MBI analyzer 28 can include a sonication unit 42 and a heater 44 that are
configured
and positioned to engage the sample holder 38 to provide sonic waves and heat,
respectively. Sonication and heat can help to lower the time required to
disperse the
clays, and can be particularly advantageous when the MFT sample is cold or has
been
stagnant. The mixer 40, sonication unit 42, heater 44 can be configured and
positioned
with respect to the sample holder 38 to be able to engage and disengage when
required.
The heater 44 can take the form of a hot plate, a heating jacket, or various
other heater
constructions.
[0058] Fig 5 also illustrates that the automated MBI analyzer 28 can
include a
methylene blue (MB) container 46 which has MB container therein. The MB
container 46
can be a receptacle that may be sealable or open, and is fluidly connected to
the sample
holder 38 via an MB titration line 48. The MB titration line can have an MB
valve 50 that
can be automatically activated to dispense a pre-determined increment of MB
from the
MB container 46 into the MFT sample in the sample holder 38. The MB container
can
also have a separate mixer or can be engaged by the mixer 40 for ensuring that
the MB
is uniform and homogeneously mixed. Various types of dispensers can be used.
CA 02948019 2016-11-08
14
Alternatively, a robotic arm can be used to engage the MB container and
dispense the
desired quantity of MB into the sample holder, e.g., by picking up the MB
container,
holding it over the sample holder, and pouring a pre-determined MB increment
into the
sample holder; or by using a robotic arm fitted with a volumetric syringe,
that can draw a
pre-determined volume of MB and dispense it into the sample holder. In another
example, the robotic arm can manipulate a dip stick or a syringe which is
dipped into the
sample and then placed against the filer paper so that a drop of the mixture
touches the
filter paper and forms the spot. Various other types of dispensers and
dispensing
methods can also be used.
[0059] The
automated MBI analyzer 28 can also include a syringe 52 or another
type of dispensing device in fluid communication with the sample holder 38.
The
syringe 52 is configured to receive a MB-titrated sample 54 (i.e., a mixture
of the sample
and one or more increments of the MB) from the sample holder 38 and dispense
the
MB-titrated sample 54 onto an underlying absorbent display material 56, which
may be
filter paper. The filter paper 56 may be provided as a strip that is dispensed
from a
roll 58 of filter paper 56 mounted to a spool 60 which is controlled to
dispense filter paper
when needed. Alternatively, the filter paper arrangement could include a
circular disc of
absorbent material on which the drop of MB-titrated sample could be deposited
at
different locations, where either the disc rotates or the dispenser moves
(e.g., circularly)
to provide drops at different locations around the disc of filter paper; and
the used filter
paper disc is removed to expose a new sheet.
[0060] Dispensing
of the MB-titrated sample 54 from the syringe 52 forms a
spot 62 on the filter paper 56. The spot 62 can then be analyzed automatically
using an
image acquisition and processing system that includes a camera 64 and an image
processor 66. The camera 64 can be positioned above the filter paper 56 to
acquire a
digital image 68 that includes the spot (i.e., "digital spot image"). The
camera 64 can
acquire the digital spot image 68 in the same location where the spot was
formed which
would typically be directly below the syringe 52, thus without moving the
filter paper 56,
or the camera 64 can acquire the digital spot image 68 after the filter paper
56 is
displaced to a location directly below the camera 64 and offset from the
syringe drop
path (as in Fig 5). The camera 64 can be oriented in the desired manner so
that its field
of view includes the spot 62 and surrounding unaffected filter paper 56. The
camera 64
can include a photosensor array made of a plurality of photosensitive elements
CA 02948019 2016-11-08
configured to generate the digital spot image 68 by detecting the intensity of
light
originating from within the field of view of the camera 64 and by converting
the detected
light intensity into electrical data. The photosensor array can be embodied by
a
complementary metal-oxide-semiconductor (CMOS) or a charge-coupled device
(CCD)
image sensor, but other types of sensor arrays could alternatively be used.
The
camera 64 can also include a color filter array overlying the photosensor
array and
configured to selectively filter incoming light according to wavelength to
capture color
information about the spot 62 and the surrounding unaffected filter paper 56.
[0061] The digital spot image 68 acquired by the camera 64 is sent to the
image
processor 66. The image processor 66 includes modules for processing the
digital spot
image 68 in order to determine whether or not the MB titration is complete. If
the titration
is incomplete, the image processor 66 supplies that information to a
controller 70 which
can activate further titration of the MFT sample. If the titration is
complete, the
controller 70 can terminate the titration and can also provide output MBI data
72 which
can be displayed, recorded and/or provided to another unit of the overall
process (e.g.,
flocculant dosage controller 74).
[0062] Still referring to Fig 5, the controller 70 can be coupled to a
number of
components of the automated MBI analyzer 28. The controller 70 can activate
the
components of the analyzer 28 during different stages of the titration to
perform different
tasks. For example, the controller 70 can be coupled to the mixer 40 to
activate mixing
prior to the initial addition of MB, and also after each increment of MB is
added into the
MFT sample. Similarly, the controller 70 can be coupled to the sonication unit
42 and the
heater 44 for sonification and heating of the ME sample, which would primarily
occur
prior to initial MB addition. The controller 70 can also be coupled to the MB
valve 50 to
control the amount of the MB increment and the timing of its addition into the
MFT
sample. The controller 70 can also be coupled to the syringe 52 to control the
amount of
the dispensed sample and the timing of discharging onto the filter paper 56,
which
should be coordinated with the control of the filter paper roll 58 to ensure
that fresh filter
paper section is provided for each spot. The controller 70 can also be coupled
to the
camera 64 to control the position, timing and characteristics of the image
acquisition
(e.g., lighting, focus, etc.), although such characteristics can be determined
and
controlled by the camera itself. The controller 70 can communicate with these
and other
components of the analyzer 28 in order to receive relevant information and
activate
CA 02948019 2016-11-08
16
components in a coordinated and timely manner. The controller 70 can be
configured to
provide fully automated operation of the analyzer 28.
[0063] If the image processor 66 provides information to the controller 70
that the
titration is incomplete, the controller 70 can initiate further titration of
the sample by
activating the MB valve 50 to provide an additional increment of MB into the
MFT
sample, activating the mixer 40 to mix the sample, activate the filter paper
mechanism to
provide a fresh section of filter paper 56 below the syringe 52, activate the
syringe 52 to
dispense some of the sample onto the fresh section of filter paper 56 to form
another
spot, and activate the camera to acquire another spot image 68. The additional
spot
image 68 will then be provided to the image processor 66 to determine, once
again,
whether the titration is complete.
[0064] In some implementations, the titration steps are performed serially
such that
an additional step is not performed unless and until the image processor
generates an
output that the titration is incomplete. In alternative implementations, a
subsequent
titration step can be initiated prior to the output regarding whether the
titration is
complete.
[0065] Referring still to Fig 5, various components of the analyzer 28 may
be
manipulated by a robotic arm 75 that may be mounted on a frame along with the
other
components. The robotic arm 75 can be configured and positioned to
automatically
engage with various components that may be moved with respect to each other,
such as
the sample holder 38, the mixer 40, the sonication unit 42, the heater 44, and
so on.
Multiple robotic arms can also be provided for making simultaneous component
manipulations. Alternatively, other mechanisms may be provided in place of the
robotic
arm to provide desired displacement or manipulation of the analyzer
components.
[0066] In some implementations, a single unit or component of the automated
MBI
analyzer 28 can perform multiple functions. For example, the mixer 40 can have
an
integrated heater 44 that can be actuated for the initial dispersion of the
clays in the MET
sample, rather than having two distinct mixer and heater components. In
addition, the
robotic arm 75 can be configured to provide the mixing and thus can act as a
displacement mechanism as well as the mixer 40.
CA 02948019 2016-11-08
17
[0067] It should be noted that the automated MBI analyzer 28 can include
various
other components. For example, the automated MBI analyzer 28 can include an
acidification unit (not illustrated) which adds acid (e.g., sulfuric acid) to
the MFT sample
to inhibit the influence of certain compounds that may be present and controls
pH
effects. Nevertheless, for MFT samples the clays have been substantially
dispersed due
to the processing of the oil sands ore in the bitumen extraction operations
generating the
MFT. Thus, for MFT samples, the pre-treatments required for ensuring adequate
dispersion and preparation of the clays are less demanding and extensive
compared to
other types of samples (e.g., mined oil sands ore). In addition, the automated
MBI
analyzer 28 can include an oxidation unit (not shown) to add an oxidizing
compound
(e.g., hydrogen peroxide) into the sample as a pre-treatment to reduce or
remove effects
of certain organic compounds that may be present in the sample. Furthermore,
the
analyzer 28 may include a dilution device (not shown) for adding water (e.g.,
deionized
water) to the sample.
[0068] It should be noted that the automated MBI analyzer 28 components
illustrated
in Fig 5 can be mounted with respect to support structure that can be
constructed as an
at-line unit that is relocatable to different points of an MFT flocculation
and dewatering
operation, particularly points upstream of flocculant injectors. Referring to
Fig 10, the
analyzer 28 can be mounted to a frame 76 which can have wheels 77 and/or a
structure
facilitating relocation via a vehicle, such as a forklift or truck (not
illustrated). In some
scenarios, the analyzer 28 can be set up on a skid and/or within an enclosure,
such as a
shipping- or office-type container (not illustrated).
[0069] Fig 10 illustrates a relocatable MBI analysis unit 78 that includes
the wheel-
mounted frame 76 on which the automated MBI analyzer 28 is mounted. The
relocatable
MBI analysis unit 78 can also include a cover 80, which may be removable, for
covering
all or part of the automated MBI analyzer 28, to facilitate protection from
the
environment. The relocatable MBI analysis unit 78 can also include a sample
support 82
that can be uncovered and can be used by an operator for placing tools,
containers, and
the like, which may be useful for the MBI analysis. There may also be an
external
receptacle 84 for receiving the MFT sample 30 from the source 12 or in-line
flow of
MFT 14, depending on the location of the relocatable MBI analysis unit 78.
Obtaining the
MFT sample 30 may include opening an MFT sample valve 86 and drawing an amount
CA 02948019 2016-11-08
18
of MFT that can be discharged into the receptacle 84 or directly into the MFT
sample
holder (not illustrated here) of the analyzer 28.
[0070] The analyzer 28 may also be configured and positioned to facilitate
visual
inspection of various components and compounds used in the analysis. For
example,
the sample holder may be composed of a transparent material to enable visual
inspection of the MFT sample by an operator and/or by the camera, in order to
inspect
the MFT sample for various characteristics such as clay dispersion, bitumen
separation,
segregation, and the like. The analyzer 28 may include an MFT sample analysis
component (not illustrated) for automated inspection of various properties of
the MFT
samples (e.g., composition, temperature, yield strength, viscosity, and so
on).
[0071] Referring still to Fig 10, the relocatable MBI analysis unit 78 can
also include
a transmitter 88 coupled to the analyzer 28 to transmit data to other control
units,
devices, and/or receivers, which are part of the MFT flocculation and
dewatering
operation and/or the bitumen extraction facility. The transmitted data
includes the MBI
data generated by the image processor, and can also include additional data
regarding
the MFT, environmental conditions, or analyzer functioning. The additional
data may be
obtained in automated fashion. In some implementations, the transmitter 88 is
configured to transmit the MBI data in various forms (e.g., wireless). In some
implementations, the transmitted MBI data is received by a flocculant control
unit 90
which controls the flocculant dosage into the MFT flow 14, for example by
regulating the
flow rate of the flocculant solution 18 injected into the MFT flow 14 or the
flocculent
concentration within the solution.
[0072] In some scenarios, where there are multiple MFT sources 12 and/or
feed
pipelines, as illustrated in Fig 7, there may be multiple automated MBI
analyzers 28 each
provided at a distinct location for analyzing a distinct MFT source or flow.
Fig 8 illustrates
a scenario where there is a single main MFT source 12 with multiple feed
pipelines that
supply MFT to different flocculant injectors (not illustrated here), and each
of the feed
pipelines can have its own automated MBI analyzer 28.
[0073] Fig 9 shows a scenario where a single automated MBI analyzer 28 is
used for
two different MFT sources 12 (e.g., from two different ponds). In such
configurations, the
automated MBI analyzer 28 can be equipped with multiple sets of certain
components
CA 02948019 2016-11-08
19
(e.g., multiple sample holders) to enable parallel analysis of two distinct
MFT samples.
The controller 70 can be programmed to enable the requisite timing, component
manipulation and coordination for parallel analysis. Alternatively, the
automated MBI
analyzer 28 can analyze samples in series, for example alternating between two
MFT
sources.
[0074] In some
implementations, the automated MBI analyzer can include an
automated cleaning mechanism (not illustrated) for cleaning components that
are in
contact with MB (which is a dye), MFT, and other fluids that may be used in
the titration.
The automated cleaning mechanism can include a cleaning fluid dispenser (e.g.,
for
water), a used cleaner receptacle, and optionally a brush or cleaning
implement.
[0075] Referring
to Fig 5, the automated MBI analyzer 28 can be viewed as
including two main units: a titration unit (T) and a digital image acquisition
and
processing unit (DIAP) which are integrated to provide MBI analysis. The
titration unit
includes the sample and fluid handling components, while the DIAP includes the
digital
camera 64 and image processor 66. The controller can be a separate control
unit or can
be integrated with the titration unit or the DIAP.
[0076] Now turning
to Fig 6, the automated image processing will be discussed in
greater detail. The image processor can be configured in various ways to
analyze the
digital spot images 68 generated by the camera during the automated titration.
In some
implementations, each digital spot image 68 is analyzed by taking into account
the hue
and chroma of the "halo" that is formed. As discussed above, digital spot
images are
acquired by the camera and represent the spots that are formed by the
discharged
samples that have been subjected to stepwise addition of MB.
[0077] Referring
to Fig 6, each digital spot image 68 includes at least a
background 92 (i.e., surrounding filter paper), a central blue spot 94 and a
water
mark 96. The digital spot image 68 is a digital color representation of the MB-
MFT spot
formed on the filter paper.
[0078] The image
processor can be configured to determine color property values
at multiple locations of the digital spot image 68, identify inflection points
of color
property values, compare color property values at the identified inflection
points to
reference color property values, and determine whether the titration is
complete based
CA 02948019 2016-11-08
on the comparison between the measured and reference values. In some
implementations, the color property values may include hue, saturation and
chroma, and
such properties are measured from a starting point within the central blue
spot 94 (e.g.,
center of the image) in distance intervals, passing through the blue spot 94,
the water
mark 96 until the background 92 is reached. The color property values (e.g.,
hue,
saturation and chroma) can thus be measured along a relatively linear path
from within
the blue spot 94 until the background 92. The color property values can be
measured
along multiple paths (e.g., both x- and y-axes). The measurements can be taken
in a
center-out fashion, or alternatively can be taken staring at the background
and moving
inward toward the center. The blue spot 94 can have a central brownish clay
region 98
and an outer blueish dye region 100.
[0079] The measured color and position information can be plotted in order
to
identify the inflection points that correspond to three main transition
points: (i) the inner
transition 102 from the clay region 98 to the outer blueish dye region 100,
(ii) the
intermediate transition 104 from the blueish dye region 100 to the water mark
96, and
(iii) the outer transition 106 from the water mark 96 to the background 92
(filter paper).
Fig 6 illustrates the different color regions and transition points of the
digital spot
image 68. These transitions correspond to inflection points when the color
properties are
converted to numerical values.
[0080] Determination of the inflection points can include various
techniques. When
certain changes in color are relatively stark or have step-change
characteristics, the
corresponding inflection point can be relatively straightforward to determine.
In some
scenarios, the changes in color may be more gradual, in which case there can
be a
mathematical algorithm provided to determine the actual inflection point for
color. There
are various known techniques for inflection point determination which can
include a
number of estimations and/or calculations, and can include numerical or
analytical
techniques.
[0081] The image processor can be configured to identify a blue-green halo
which is
the hallmark of the end point of MB titration. The numerical values for
identifying the
color properties of the digital spot image can be based on various color
systems, such
as the "Munsell" color system, a "Lab" color space (e.g. CIELAB), or color
appearance
models (e.g., CIECAM02). In the Munsell color system, colors are specified
based on
CA 02948019 2016-11-08
21
the three color dimensions of hue, value (lightness) and chroma (color
purity); and the
image processor can be configured such that the calibration value for the blue-
green MB
halo is within the hue range of 2.5G to 10BG on the color wheel, for example,
or a
narrower blue-green range. The implemented blue-green range can be based on
calibration of a particular instrument with MB dye. The chroma calibration
value can be
the same or different for different hues (e.g., minimum value of /4), and the
value
calibration value can be the same or different for different hues (e.g.,
minimum value of
3/). Narrower ranges can also be used. The implemented range for the hues and
any
other color properties can be based on calibration of a particular instrument
with MB dye.
[0082] In some
implementations, the image processor includes analysis modules
configured to perform at least the following steps:
(A) Measure the background 92 of the digital spot image 68 and translate it
into a
numerical value (based on the hue and chroma) for the background 92.
(B) Measures the center of the digital spot image 68 and translate it into a
numerical value (based on the hue and chroma).
(C) Starting from the center, measure the hue and chroma and translate the
values into a numerical value at distance intervals (e.g., 0.5 mm), on the
positive x-axis; and continue to do the measurements and save the data in a
table until the measurement match the value obtained in step (A). Note that
the intervals at which the hue and chroma are taken can be pre-determined
distance intervals (e.g., 0.5 mm or 1 mm) or can be a number of pixels (e.g.,
every pixel, every 50 or 100 pixels, etc.).
(i) Draw a curve based on the values determined in step (C), and
identify the inflection points. There will be three inflection points:
First, when the spot transitions from the clay color to blue color;
second, the change in color from blue to the water mark, due to
water blotting; and third, from water stain to background color.
(ii) Average the value obtained between the first and second
inflection points, and compare it with the value saved in the
calibration table of the program. This average value represents
CA 02948019 2016-11-08
22
the transition of color from the color of titrated clay to the color of
non-titrated MB solution.
(iii) Average the value obtained between the second and third
inflection points, and compare it with the value saved in the
calibration table of the program. This average value represents
the transition of color from the color of non-titrated MB solution
to the color of the water mark.
(D) Starting from the center, measure the hue and chroma and translate it into
a
numerical value at distance intervals (e.g., 0.5 mm or 1 mm), or a number of
pixels (e.g., every pixel, every 50 or 100 pixels, etc.)., on the positive y-
axis;
continue to do the measurements and save the data in a table until the
measurement match the value obtained in step (A). The distance intervals for
the y-axis can be the same or different compared to those used for the x-axis.
(i) Draw a curve based on the values determined in step (D), and
identify the inflection points. There will be three inflection points:
first, when the spot transitions from the clay color to blue color;
second, the change in blue color to watermark due to water
blotting; and third, from water mark to background color.
(ii) Average the value obtained between the first and second
inflection points, and compare it with the value saved in the
calibration table of the program.
(iii) Average the value obtained between the second and third
inflection points, and compare it with the value saved in the
calibration table of the program.
(E) The inflection point values for steps (C) and (D) are compared to the
calibration curve. The same or similar comparison can be done here as was
done for steps (C)(ii), (C)(iii), (D)(ii) and (D)(iii). The comparison can be
done
based on the calibration values stored in the memory of the image processor.
The y-axis inflection points can be determined notably in order to assess or
accommodate any irregularities in the drop shape. By performing the
CA 02948019 2016-11-08
23
determination along two axes of the drop (e.g., x-axis and y-axis), the
robustness and accuracy of the analysis can be enhanced.
(i) If the values for steps (C) and (D) match with the calibration
values, then the end point has been reached and a signal can
be sent to the titration components to pause to allow drying of
the spot, and then take another digital image after the prescribed
drying time. Step (F) is then performed.
(ii) If the values for steps (C) and (D) do not match with the
calibration values, then a signal is sent to the titration
components to continue the titration procedure, i.e., add a
further increment of the MB to the sample.
(F) After drying, the image processor again performs steps (A) to (D).
(i) If the repeat "dry" measurements and analyses match the
calibration values then a signal can be sent to the titration
components to stop the titration test and move to a next sample.
(ii) If the values in steps (C) and (D) for the "dry" image do not
match the calibration values, then a signal is sent to the titration
components to continue the titration procedure, i.e., add a
further increment of the MB to the sample.
[0083] It should be noted that the digital spot image can be processed
based on
various protocols in order to identify different color regions (e.g., based on
hue, chroma,
etc.) and transitions (e.g., based on changes in hue, chroma, etc., at
different locations
of the image).
[0084] The automated MBI analyzer can thus conduct MBI titration of MFT
samples
and uses digital image capturing and evaluation of color properties (e.g., hue
and
chroma) for customized determination of MBI on MET slurry samples.
[0085] In some implementations, the automated MBI analyzer uses color
properties
of at least hue and chroma for the titration. Alternatively, other sets of
color properties
could be used for the digital image analysis. In addition, depending on the
image capture
CA 02948019 2016-11-08
24
settings (e.g., the light intensity detected by the camera or emitted by a
light source, the
digitization and storage of the image, etc.), the image processor can be
configured to
analyze various types of color data and properties. In other alternative
implementations,
the digital camera is configured to capture wavelengths that are not
necessarily in the
visible spectrum to provide further potential enhancements over manual
operators in
terms of assessing the properties of the digital spot image. In this regard,
it should be
noted that the term "light" as used herein is intended to refer to radiation
in any
appropriate region of the electromagnetic spectrum and, in particular, is not
limited to
visible light, but can also include non-visible regions of the spectrum (e.g.,
infrared and
ultraviolet, etc.).
[0086] Various titration protocols can be implemented using the automated
MBI
analyzer. For example, in some implementations the volume of the MFT sample
can be
between 1 milliliter and 20 milliliters depending on the volume of MB required
to
complete the titration. A total titration volume of MB can be in the range of
0.5 milliliter to
milliliters, for example. The initial MFT sample volume is transferred to the
sample
holder and its mass and volume can be obtained by integrated mass and volume
measurement components.
[0087] The following is an example protocol for the automated MBI analyzer:
(a) Transfer a pre-determined volume (e.g., 5 milliliters) of MFT into the
sample
holder.
(b) Optionally, add pre-treatment chemicals (e.g., hydrogen peroxide and/or
sulfuric
acid) if desired.
(c) Heat the mixture, optionally to boiling on a hotplate, e.g., for 5 to 15
minutes
ensuring that the mixture retains liquid at the end of heating.
(d) Add water to dilute the mixture to a pre-determined volume (e.g., 50
milliliters).
(e) Mix the sample to ensure dispersion and homogeneity.
(f) Initiate MB increment addition to the mixed sample. Each MB increment can
be
of the same volume; however, if an approximate amount of MB necessary to
reach endpoint is known, based on previous tests or a value input by an
CA 02948019 2016-11-08
operator, then one or more large increments can be added at the beginning of
the titration and smaller volumes can be added closer to the approximate end
point. For each MB increment:
(i) Add a pre-determined volume of MB;
(ii) Mix the MB-MFT sample, e.g., for 15 seconds to 1 minute, by
shaking the sample holder.
(iii) Dispense at least one drop of the sample onto the filter paper,
and wait a short time until spot forms.
(iv) Acquire the digital image of the spot. The time delay between
drop contact with the filter paper and acquisition of the image
can be such that the spot has reached a maximum and stable
diameter. The time delay can be about 10 to 20 seconds.
(v) Process the digital image of the spot to determine whether end
point of the titration has been reached.
= If titration end point has been reached for the digital image of the
wet spot: send a signal to the titration unit to wait a pre-
determined drying time to allow the spot to dry (e.g., 2 minutes);
then perform steps (iv) and (v) again on the digital image of the
dry spot to determine whether end point of the titration has been
reached.
= If titration end point has not been reached for the digital image of
the wet spot, send a signal to the titration unit to perform the
next titration run of step (f), which can repeated on a closed-loop
basis until the end point of the titration is reached.
= If titration end point has been reached for the dry spot, send a
signal to the titration components to cease titration on the
sample.
CA 02948019 2016-11-08
26
= Optionally, if titration end point has been reached for the digital
image of the wet spot and/or the dry spot: send a signal to the
titration unit to perform at least one additional test on the same
sample mixture, i.e., step (f) without sub-step (i), and provide a
pre-determined amount of mixing/agitating and/or reaction time
(e.g., 1 to 3 minutes) for the sample prior to the additional test.
= Optionally, various characteristics of the digital image can be
obtained, including the diameter or size of different parts of the
spot, the shape of the spot, etc., which can be recorded for
analysis and refinement of the titration unit and/or the DIAP.
(g) Cease titration of the sample.
(h) Generate the MBI value based on input variables regarding volume of MB
added,
normality of MB solution used, and mass of dry sample, according to the
following equation:
(meg _Pas MB X Normality of MB
MBI ____________________________________________ X100
100gi mass of dried sample (g)
(i) Provide MBI value for display, transmission, and/or recording.
[0088] The calibration values can be determined based on previous manual
laboratory testing and correlations with the analyzer's image processing
results. In
addition, computer modelling can be done regarding the digital image in order
to provide
further information for accurate titration end point determination by the
image processor.
[0089] Referring now to Fig 11, a conceptual graph of the manipulated value
(obtained from the algorithm based on the measured color properties) versus
distance
(pixels) is shown. For example, the hue and chroma values are converted into a
numerical "color property value" which can then be charted against the
location and
compared to calibration curves. The chart indicates that where there is a
transition from
one color to another, there will be an inflection of the "color property
value" (CPV), which
itself can be determined based on the hue and chroma values read by the image
processing system. In some implementations, the "color property value" will be
a
CA 02948019 2016-11-08
27
function of hue and chroma variables, and may in some cases include additional
variables as well. The function, CPV = f(hue, chroma), can be determined
empirically,
analytically, or by combined analytical-empirical methods. In the example of
Fig 11, a
clear dip can be seen spanning from about pixel 220 to about pixel 300
indicating an
inflection point and thus the presence of a notable color change at that
region of the
digital spot image. The depth and length of the dip can be factors that are
considered in
determining whether a certain color change has occurred and thus whether
titration
should be terminated.
Alternative analyzer implementations
[0090] In some implementations, the automated analyzer can be adapted to
use
titration compounds other than MB and/or sensors other than a digital camera
to obtain
digital information regarding a titration sample spot.
[0091] For example, the automated analyzer can use a titration dye which
reacts
with clay or other components in the slurry such that titration can provide
useful
information regarding the composition of the slurry. When titration dyes are
used, the
digital information that is obtained can be digital color images that are
processed
according to certain color properties, such as hue and chroma as described
above.
[0092] In another example, the automated analyzer can use a titration
compound
which reacts with clay or other components of the slurry such that the
resulting titration
spot does not necessarily exhibit notable color characteristics. While it
would be difficult
for a human operator to ascertain any reliable information from such non-color
titrations,
the sensor and processor units can be configured and operated based on non-
visible
characteristics and may therefore leverage other types of light sources,
wavelengths,
acquisition techniques and processing techniques to yield useful information
regarding
the sample. For instance, while visible light may provide no meaningful
information
regarding progress of the titration, non-visible light (e.g., infrared,
ultraviolet, etc.) may
be able to demonstrate titration progress in order to provide information on
sample
composition.
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Clay-containing slurry implementations
[0093] In some implementations, the automated MBI analyzer is particularly
suited
for slurry samples that are obtained from a tailings pond and/or have been
previously
subjected to processing such that the clays are already substantially
dispersed in the
aqueous medium of the tailings. This highly dispersed state of the clays
facilitates
operation of the automated MBI analyzer since dispersion of the clays does not
require
elaborate assessment, time or operation. The automated MBI analyzer is thus
particularly advantageous for analyzing samples having minimal or no
preparation
requirements, as is the case for MFT, and within the context of a treatment
process of
the clay-containing material where clay content can both vary frequently and
have an
impact on process variables.
[0094] In alternative implementations, the automated MBI analyzer can be
adapted
for analysis of other clay-containing slurry samples that may require
dispersion pre-
treatments that include chemical addition, mixing, sonication, and so on. For
example,
drilling fluids, fracking fluids, core sample, slurry materials including
particulate mined
ore, slurry streams that are withdrawn from various pipelines or unit
operations (e.g.,
separator underflows, overflows, middlings, and/or feed streams) or in an
extraction
process (e.g., primary or secondary oil sands extraction, other mineral
extraction
process).
[0095] The automated MBI analysis can also be used to determine slurry MBI
in
order to regulate various downstream unit operations. In one example, as
discussed
above, the MBI of the MFT sample is used to control or inform downstream
flocculation
and dewatering operation, notably to adjust the flocculent concentration on a
clay basis.
In another example, the MBI of an oil sands slurry sample can be used to
control a
downstream bitumen extraction operation based. Such an oil sands slurry can be
various types of slurry, such as oil sands tailings which are processed to
recover
additional bitumen and/or other components (e.g., metals), oil sands
hydrotransport
slurry that is supplied to a flotation vessel, oil sands bitumen froth that is
supplied to
secondary extraction (e.g., that uses naphthenic or paraffinic solvent
extraction), or oil
sands slurry streams that are supplied to any secondary or tertiary separation
units (e.g.,
gravity settlers, flotation vessels, inclined plate separators, thickeners,
cyclones,
centrifuges, etc.).
CA 02948019 2016-11-08
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[0096] The automated MBI analysis can be used for various samples having
different approximate clay contents. MFT samples may have, for example, solids
concentrations between about 15 wt% and about 45 wt% (or higher), and the clay
content can be at least 50 wt% on a total solids basis. MFT samples can often
have clay
contents of at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90
wt%, or at least
95 wt% on a total solids basis, while the solids content is often between 20
wt% and
40 wt% or between 25 wt% and 35 wt%. Other clay-containing samples that have
such
high clay contents can also be used with the automated MBI analysis.
Automated analyzer use with MFT flocculation
[0097] As mentioned above, the MBI data generated by the automated MBI
analyzer
can be used for process control or assessment in MFT flocculation and
dewatering
operations.
[0098] In MFT dewatering operations where MFT is dredged from one or more
tailings ponds that have received extraction tailings from different sources
of the
extraction facility, the MFT feed that is subjected to flocculation and
dewatering can have
variable clay content and other components. In addition, flocculating the MFT
using an
anionic polymer (e.g., a sodium polyacrylamide polyacrylate co-polymer with
30%
anionicity and a molecular weight over 10,000,000) is advantageously performed
with a
flocculant dosage on a clay basis rather than on a total solids basis.
Conducting
automated, reliable and timely MBI analyses can provide notable benefits in
terms of
enhancing process control of MFT flocculation and dewatering operations, as
the MBI
can provide timely information for feed-forward control of flocculant dosing
and achieving
enhanced water release and drying of treated MFT.
[0099] It has been found that in MFT flocculation and dewatering operations
the clay
content in the MFT can vary by about 2% to 5% per day, which can have a
notable
impact on flocculant dosage. The automated MBI analyzer can generate MBI data
at a
frequency enabling the flocculant dosage to be controlled to account for the
clay
variations that tend to occur in the MFT feed. In some implementations, the
potential
benefit in terms of improved flocculation consistency and reduced polymer
dosage can
result in significant savings in terms of flocculant usage in addition to
higher production
rates of dried MFT. In addition, while typical variations in MFT clay content
may be in the
CA 02948019 2016-11-08
range of 5% per day, there may also be greater step-changes in clay content
when the
source of the MFT is changed or the dredging equipment is moved within the
tailings
pond, and thus the automated MBI analyzer can enable rapid adjustment of the
flocculant dosage in response to step-changes and thus avoid waste of
flocculant and
off-specification material that could result due to inaccurate flocculant
dosage.
[00100] Two notable parameters can be used in the control and optimization of
MFT
flocculation and dewatering operations: (1) flocculant dosage, and (2) mixing
of the
flocculant and MFT. Optimal polymer flocculant dosage is based on active clay
area in
the MFT feed, which can be indicated by MBI data. In some scenarios, the MBI
data
generated by the automated analyzer can be used to adjust mixing parameters
instead
of or in addition to flocculant dosage. For example, high clay content MFT may
benefit
from higher mixing energy, which could be provided by increasing the flow
rates or
providing mixing devices, or manipulation of the MFT feed properties which
could
include additional shear-thinning and/or dilution prior to flocculation to
reduce viscosity
and yield strength of the MFT that is mixed with the flocculant. Thus, the
automated MBI
analyzer can be used to enhance process control of various parameters of MFT
flocculation and dewatering operations.
Optional flocculation and dewatering features
[00101] Some implementations and features of MFT flocculation and
dewatering
operations have been described herein, but it should be noted that various
modifications
could be made to the particular implementations and features that have been
disclosed.
[00102] For example, it should be noted that other types of dewatering
chemicals can
be used instead of or in addition to the polymer flocculant, particularly
those that are
advantageously dosed on a clay basis. In addition, while the units illustrated
in Fig 1 may
be provided as part of an in-line pipe-based system in which the materials are
transported, treated and mixed in a continuous manner along a pipeline prior
to being
deposited, in some alternative implementations it is possible to use units
that are not in-
line pipe-based but are rather tank-based or batch-based, for example, to
perform
certain process steps. In some implementations, the flocculant comprises an
anionic
polymer flocculant, which may be a sodium salt of an anionic polymer, such as
a 30%
anionic sodium polyacrylamide-polyacrylate co-polymer. The polymer flocculant
may
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31
also have a desired high molecular weight, for instance over 10,000,000, for
certain
flocculation reactivity and dewatering potential. The polymer flocculent may
be generally
linear or not according to the desired shear and process response and
reactivity with the
given MFT.
[00103] It should further be noted that the MBI data can be used in
combination with
other data regarding properties of the MFT in order to control the
flocculation and
dewatering operation. For example, certain properties of the MFT (e.g.,
bitumen content,
sand content, yield stress, viscosity, clay-to-water ratio (CWR), sand-to-
fines ratio (SFR),
salt content, and various other chemical and rheological properties) can be
determined
by various methods and can be used in combination with the MBI data to control
the
process.
[00104] It is also noted that the flocculent injection unit can have
various designs,
such as an in-line co-annular injector or other types of injectors that
rapidly disperse the
flocculent solution into the MFT. The MBI data that is used for process
control can be
used in different ways that are tailored to the particular design of the
flocculent injection
unit. In addition, the downstream handling of the flocculation material can
include
pipelining and expelling into a deposition area for dewatering. The pipelining
can be
managed according to various techniques that have been previously described,
e.g.,
where the flocculation material is subject to sufficient in-line shear to be
within a water-
release zone upon deposition. The water-release zone can be where the
flocculated
material has passed a peak yield stress but is not over-sheared, such that the
water-
release characteristics of the material are in a maximum region. The design
and
operation of the pipeline can be conducted according to the Camp Number, for
example.
It is noted that other downstream handling equipment can be used to handle the
flocculation material in between flocculation and dewatering.
[00105] The dewatering can be performed by expelling the flocculated MFT onto
a
sub-aerial deposition area in thin lifts, or into a permanent aquatic storage
structure
where the flocculated material dewaters near the bottom of a lake-like
structure that has
an upper water layer. The dewatering can also include various dewatering
devices,
which may be used alone or in combination with the sub-aerial deposition area
or the
permanent aquatic storage structure. In this regard, the automated MBI
analyzer can
CA 02948019 2016-11-08
32
also enhance accurate tracking and estimation of quantity of clay material
that is treated
and ultimately reclaimed as part of a tailings dewatering and reclamation
efforts.
