METAKAOLIN STUDY
Pre-Feasibility Review of the Potential for
Developing Metakaolin from Oil Sands Operations
for Use in Concrete
Prepared for:
Action Plan 2000 on Climate Change – Minerals and Metals
Prepared by:
Michel de Spot, P.Eng.
Maggie Wojtarowicz, E.I.T.
November 2003
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Table of Contents
1. Executive Summary......................................................................................................1
2. Introduction....................................................................................................................1
2.1. Study Objectives.........................................................................................................2
2.2. Scope of Report ..........................................................................................................2
2.3. About EcoSmart..........................................................................................................4
3. Background.....................................................................................................................4
3.1. Definitions...................................................................................................................5
3.2. Use of Metakaolin in Canada...................................................................................6
3.3. Use of Metakaolin in the World...............................................................................6
3.4. Investigations of Metakaolin Production from Oil Sands Operations...............6
3.5. Research into the Use of Metakaolin as an SCM..................................................7
4. Technical Evaluation ....................................................................................................7
4.1. Extraction and Calcination Process.........................................................................7
4.2. Performance in Concrete as an SCM ......................................................................9
5. Economic Evaluation..................................................................................................10
5.1. Cost of Production of CMFT..................................................................................10
5.1.1. Cost of Extraction of MFT...........................................................................10
5.2. Cost of Testing CMFT for Use as SCM ...............................................................10
5.3. Cost of Transportation.............................................................................................10
5.4. Demand vs. Cost vs. Price ......................................................................................11
6. Environmental Evaluation........................................................................................14
7. Summary of Findings.................................................................................................15
7.1. Properties of Various SCMs and PC.....................................................................15
7.2. Benefits of CMFT Production and Usage as SCM.............................................16
7.3. Drawbacks of CMFT Production and Usage as SCM........................................16
8. Conclusions....................................................................................................................16
8.1. General.......................................................................................................................16
8.2. Oil Sands Industry....................................................................................................17
8.3. Cement/Concrete Industry......................................................................................17
8.4. EcoSmart Concrete Project.....................................................................................17
9. Future Work .................................................................................................................18
9.1. EcoSmart....................................................................................................................18
9.2. Research Community...............................................................................................18
9.3. Oil Sands Industry....................................................................................................18
9.4. Concrete Industry.....................................................................................................18
10. References......................................................................................................................18
11. Appendices.....................................................................................................................19
List of Tables
Table 1: Sample Calculation for Syncrude Kaolin Production Capability ...................4
Table 2: Relationship between Demand, Supply, Cost and Price of CMFT ...............12
Table 3: Comparison of the Properties of Various SCMs and PC.................................15
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List of Figures
Figure 1: Scope of the EcoSmart™ Metakaolin Study........................................................3
Figure 3: Tynebridge Extraction Process...............................................................................8
Figure 4: Distances between Production Site and Potential Market for CMFT........11
Figure 5: Relationship between Demand, Cost and Price of CMFT.............................11
Figure 6: Market Analysis Curve: Price vs. Demand........................................................13
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1. Executive Summary
The following report evaluates the potential of metakaolin recuperated from oil sands
tailing ponds in North Alberta, as a supplementary cementing material (SCM) for
concrete.
Oil sands operations produce vast quantities of tailings containing extremely fine clays
that prevent the reuse of process water from the tailings ponds. Preliminary research has
indicated that this fine material can be processed into a product similar to metakaolin
(MK). Metakaolin is a valuable product with many commercial uses, including as a high
performance SCM. Extracting the fine clay from the ponds to produce SCM would have
two benefits: clarifying the process water for reuse in the operations while producing a
valuable product from a by-product.
The study finds however that, while it is technically feasible, the concept is uneconomical
for many reasons. The material that can be produced from the pond – called calcined
mature fine tailings or CMFT – while similar to MK, has lower quality and performance
than the products currently on the market. Another shortcoming is that CMFT is grey
while metakaolin from virgin kaolin is white. Therefore, in performance and appearance,
CMFT cannot compare to MK. Rather, it is more like fly ash (FA), another SCM
abundantly available in Alberta, but at a much lower price than MK. Furthermore, the oil
sand region is isolated, landlocked and far from the market for concrete. Because of the
cost of extracting, drying, calcining, and transporting the material, CMFT cannot
compete against FA, and the study concludes on the non-feasibility of the concept.
The oil sand industry still wants to resolve its water and pond issues, and continues to
investigate ways to process the fine tailing. If this research is successful and CMFT with
improved quality, color and cost can be produced, then it will be worthwhile to re-
examine the case and see if the product can be used in concrete.
2. Introduction
The use of Portland cement (PC) in concrete has significant greenhouse gas (GHG)
implications, where the manufacture of each tonne of PC generates approximately 0.9
tonnes of CO
2
emissions
1
. The “GHG signature” of concrete can be reduced by partial
replacement of PC with supplementary cementing materials (SCM). Typical SCMs
include fly ash, ground granulated blast furnace slag, and silica fume, ground limestone,
natural pozzolans and metakaolin.
It has been discovered that the by-product of oil sands operations, namely the clay from
tailings ponds, can be processed into a material with similar properties to metakaolin for
use in paper making, ceramics, concrete, and other industrial applications. The oil sands
operations in northern Alberta produce vast quantities of tailings, which are stored in
gigantic tailings ponds. Fine clay, which represents a significant part of these tailings,
takes a long time to settle, and therefore makes it very difficult to recycle the process
water. Extraction and processing of this clay is a promising means of turning the by-
product into a value-added product and clarifying the process water for reuse in the
operations.
Starting from existing scientific and technical information produced by the oil sands
industry and the research community, this study investigates the validity and feasibility of
the concept of reclaiming and processing the tailings into a product that can be used as an
SCM in concrete. In the study, the EcoSmart™ Concrete Project has reviewed the
1
Malhotra, 1999.
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existing research and technical studies, has commissioned an independent pre-feasibility
study, and engaged the various stakeholders in the process and decision-making.
2.1. Study Objectives
The objectives of this study are:
1. to assess the potential for developing metakaolin from oil sands operations for
use as an SCM in concrete (on technical, economic, and environmental basis);
and
2. to determine whether further exploration of this technology is justified.
2.2. Scope of Report
This study was conducted as the first phase of a two-phase feasibility study for
developing this SCM technology, as indicated on Figure 1. This report reviews the
existing information and updates the technical, economic, and environmental
assumptions for calcination of the oil sands clay. The extraction process proposed in a
previous study by Syncrude
2
, one of the oil sands operators, was assumed technically
viable and was not re-examined. This report also includes the input of the cement and
concrete industry as well as the oil sands industry in terms of the current market for this
material and willingness to develop the product, and thus, the market. Finally, the role of
the Federal Government was also taken into account in developing this technology. The
outcome of the study is a compilation and summary of the existing and EcoSmart-
commissioned information, and a clear overview of the potential and the challenges of
the concept.
2
Tynebridge, 1998.
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Figure 1: Scope of the EcoSmart™ Metakaolin Study
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2.3. About EcoSmart
The objective of the EcoSmart™ Concrete Project (EcoSmart) is to minimize the GHG
signature of concrete by maximizing the replacement of Portland cement in the concrete
mixtures with SCMs while maintaining or improving cost, performance, and
constructability. EcoSmart is an industry-government partnership generating and
transferring knowledge on reducing the CO
2
emissions from the construction industry.
3. Background
Numerous research and technical studies have pointed to the great potential of metakaolin
(MK) as a supplementary cementing material with performance similar although slightly
inferior to silica fume (SF) (see Table 3 in Section 7.1).
MK is produced by thermally processing pure kaolinite. Main sources of kaolinite as
well as the key MK producers are located in clay deposits in Georgia, U.S. and Cornwall,
U.K. The price of MK in Canada is about the same as SF and ranges between $400 and
$600 per tonne depending on the location
3
. Besides concrete, other markets for kaolin
and MK include the paper, ceramics, and fibre-cement boards industries.
Oil sands operations produce vast quantities of fine tailings collected in gigantic tailings
ponds. Fine tailings comprise mainly of kaolinite, illite, and quarts. The details of the
composition of fine tailings are provided in Section 3.1. Currently, the oil sand fields
have a total of 400 million cubic meters of tailings, which contain up to 60 million tonnes
of kaolin
4
. According to one of the oil sands companies in Alberta, their operations could
produce up to 6 million tonnes of Calcined Mature Fine Tailing (CMFT) annually
5
, a
material similar but not equal in performance to MK.
Based on rough calculations by Syncrude alone, this oil sands operator could produce 3.3
million tonnes of kaolin during their 2003 production of 85 barrels of oil, as indicated in
Table 1.
Table 1: Sample Calculation for Syncrude Kaolin Production Capability
6
Product Conversion Factors Potential for
Kaolin
Production
1m
3
of MFT 1m
3
(1280kg) of MFT containing 30%
solids (clay) produces 384kg of clay
containing 40% kaolin
153.6 kg of kaolin
per m3 MFT
1 barrel (bbl) of oil It requires 1 m
3
of oil sand to produce 1
barrel of oil.
Removal of that oil produces 1.1 m
3
of
sand containing 0.25m
3
of MFT
[(1280kg MFT x 0.25) x 0.3 solids x 0.4
kaolin]
38.4 kg of kaolin
per bbl oil
2003 Production
85 M bbl oil per
year
85 M x 38.4 kg of kaolin per year 3.3 M tonnes of
kaolin per year
3
Personal Communication, Brad Pope, Pozzolanic, July 18, 2003.
4
Wong et.al., 2002, p.1.
5
NLK, 2002, p. 4-3.
6
Personal Communication, Ted Lord, Syncrude Research, August 29, 2003.
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3.1. Definitions
Portland cement (PC) is a hydraulic cement produced by pulverizing Portland cement
clinker, usually in combination with calcium sulphate (gypsum). Portland cement clinker
is a partially fused ceramic material consisting primarily of hydraulic calcium silicates
and calcium aluminates.
7
Supplementary cementing material (SCM) is a pozzolanic material that contains high
proportions of silica and in some SCMs, alumina. When used in concrete as partial
replacement of PC, it reacts with unreacted calcium hydroxide from the hydration of PC
to form calcium silicate hydrates – the desired end product of PC hydration. SCMs
include fly ash (FA), ground granulated blast furnace slag (GGBFS), silica fume (SF),
natural pozzolans (NP), and metakaolin (MK).
Metakaolin (MK) is produced by calcining virgin kaolin.
Kaolin is a clay mineral consisting of the mineral kaolinite with admixtures of quartz and
feldspar
8
.
Tailings are the by-product of the oil sands operations, namely a mixture of water and the
solid matter remaining after nearly all the oil is removed. Tailings include sand, clay,
silt, residual bitumen and water.
Fine tailings (FT) are the small particles in suspension (10% solids) in the tailings pond,
comprised mainly of clay and silt
9
suspended in water.
Mature fine tailings (MFT) are a gel-like substance (30% solids) composed of very
slowly settling fine clay particles, and is made up mostly of water
10
. MFT contains the
clay and silt particles remaining in suspension after 2-3 years of settlement
11
. The typical
mineral composition of MFT includes approximately 23% kaolin, 17% illite (mica), 30%
quartz, and small quantities of other minerals, including iron and titanium, as well as
some organics. The iron and titanium in the MFT contribute to the unwanted dark colour
in the material. The minerals in MFT comprise mainly of silica and alumina (at a ratio of
approximately 2:1 to 3:1)
12
. Kaolinitic component in MFT can be concentrated up to
65% by weight.
13
MFT is near or at its terminal density and will not densify further
under its own self-weight in the tailings pond.
Calcined mature fine tailings (CMFT) are produced by first separating out the finer
fraction (primarily kaolin) from MFT and then heating this fraction to drive off the
hydroxyl groups (
-
OH) from the component oxides, i.e., thermal decomposition
14
.
Unlike other SCMs, MK and CMFT are unregulated products. In addition, although MK
and CMFT have similar properties, CMFT is inferior to MK because of impurities such
as silica, illite, iron, and titanium. Research indicates that the effectiveness of MK from
MFT as an SCM is approximately 85-90% that of pure MK
15
.
7
ACI Manual of Concrete Practice, 2003, ACI 116R-12-14.
8
http://www.a-m.de/englisch/lexikon/kaolinit.htm, viewed on September 4, 2003.
9
Personal Communication, Ted Lord, Syncrude Research, August 29, 2003.
10
http://www.syncrude.com/research/04_03.html, viewed July 18, 2003.
11
Personal Communication, Ted Lord, Syncrude Research, August 29, 2003.
12
Omotoso, D. et.al., 2001 Presentation and Tynebridge, 1998, p. 1.
13
Omotoso, D. et.al., 2001 Presentation.
14
INSA, 2002 and Omotoso, D. et.al., 2001 Presentation.
15
University of Calgary and Syncrude, October 2001.
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3.2. Use of Metakaolin in Canada
Currently in Canada, metakaolin is only used in small quantities in British Columbia. It
is imported from the U.S. and is used primarily in architectural and specialty concretes.
The price of metakaolin in B.C. is approximately five times the price of Type 10 Portland
cement.
16
3.3. Use of Metakaolin in the World
The NLK study indicates that MK use in the concrete industry is very limited. In North
America, it is commercially available as MetaMax®, and is produced in Georgia, USA
by Engelhard Corporation. There is also a smaller source of MK in south-eastern USA.
In the USA, the Departments of Transportation of New York, Illinois, Florida, and
California approve the use of MK in concrete. There has also been some use of MK in
concrete in New Zealand and in the Amazon Basin.
17
3.4. Investigations of Metakaolin Production from Oil Sands Operations
In 1998, Syncrude Canada commissioned a study on clay recovery from MFT generated
in its oil sands operations. The study was carried out by Tynebridge Technologies
Limited. The study described a possible extraction process, the costs of production in a
pilot plant, and scale up factors based on a pilot plant configuration that would use the
smallest equipment available. The study defined the technology required to produce
CMFT, and provided a simplified cash flow analysis indicating that the economics were
reasonable, based on a selling price of $600/tonne
18
. However, the oil sands operators,
including Syncrude, were not interested in pursuing this business venture themselves, but
were receptive to making this opportunity available to an interested independent third
party.
During 2001 and early 2002, following preliminary investigations and discussions with
the oil sands industry, EcoSmart undertook as part of its mandate to follow up and further
investigate the technical, economic and environmental potential and challenges of
developing this source of metakaolin. Through this process, EcoSmart was to serve as a
means to identify the interested third party. Stakeholder meetings were held in Alberta
with representatives of three oil sands companies, the cement and concrete industry, the
Federal Government and the research community. The meeting minutes may be found in
the Appendices. As a result, it was decided to review, as part of a pre-feasibility study,
the Tynebridge study in order to refine the numbers with more accurate information.
In 2002, following further consultations to determine the scope, EcoSmart commissioned
a pre-feasibility study. NLK Consultants Inc. was retained to complete this work. The
study involved a market analysis, desktop research and industry interviews. The
technical aspects of production and use of CMFT as an SCM were investigated, updating
the economic analysis of the Tynebridge study, and incorporating environmental
considerations. The NLK study halved the price of the MK product from the selling price
identified in the Tynebridge study by refining the process costs, assuming that the
extraction technology proposed was feasible, and assuming that a partial replacement of
Portland cement by MK could reduce the total cementitious amount in a unit of concrete.
Following the completion of the report and into 2003, EcoSmart continued consultations
with industry and the research community, concluding with a second stakeholder meeting
in Alberta to identify the next steps in the technology exploration process. The minutes
16
Bouzoubaâ and Fournier, 2003, p. 5-6, 22-23.
17
NLK, 2002, p. 4-8.
18
Tynebridge, 1998, p. 8.
Figure 2: Fort McMurray,
Alberta Oil Sands
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from this meeting are included in the Appendices. This report presents the outcome of
the entire EcoSmart undertaking regarding this alternative SCM material.
The following sections of the report provide more details of the findings from the
EcoSmart initiative.
3.5. Research into the Use of Metakaolin as an SCM
The NLK report summarizes the findings on the use of metakaolin as an SCM available
from research literature. Overall, based on this literature review, the SCM potential of
this material is promising. As a follow-up to the NLK report, EcoSmart engaged the
world-renowned expertise of the Institut National des Sciences Appliqués de Lyon
(INSA) and the materials expertise of AMEC Earth & Environmental, Burnaby, B.C., to
provide additional insights into the technical potential of CMFT as an SCM.
ICON/CANMET in Ottawa, ON, has been engaged in assessing the requirements of a
concrete testing program for CMFT and has conducted a study into the current situation
of SCMs in Canada.
4. Technical Evaluation
4.1. Extraction and Calcination Process
The extraction process described in the Tynebridge study and illustrated in Figure 3
involves the addition of sodium silicate as a dispersant (attrition mill) and removal of
residual bitumen (primary clarifier) before further thickening (secondary thickener). The
silt from the thickener is returned to the tailings ponds, while the kaolin-rich overflow is
dewatered and spray dried. The clay (containing kaolinite, illite, iron, titanium, and
traces of bitumen) is then calcined (hydroxyl groups removed at temperatures in the order
of 600-800
o
C).
19,
20
19
Tynebridge, 1998, p. 5.
20
Wong et.al., 2002, p. 6.
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Figure 3: Tynebridge Extraction Process
INSA suggests that MFT be calcined without prior removal of the 2% bitumen typically
contained in the raw tailings. This would reduce the requirement for additional fuel for
the calcining process. In addition, INSA studies have shown that a benefit of this method
in the material’s performance in concrete.
21
The MFT needs to be dried and calcined, a process that generates approximately 0.43
tonnes of CMFT per tonne of MFT
22
.
INSA suggests that an existing multi-hearth furnace at Portland cement manufacturing
plants could be used to calcine MFT on a pilot scale. A pilot-scale test of this nature will
provide more realistic information for the commercial scale production than is currently
available from laboratory scale operations.
23
The optimum calcination temperature that produces the most reactive MK is in the range
of 600-800
o
C. One study found that calcination at 700
o
C produced a MK that resulted in
the highest concrete strengths. However, little difference in concrete strength was
noticed when using MK calcined at temperatures up to 790
o
C. Reactivity of the MK did
reduce at a calcination temperature of 850
o
C
24
. It is not clear whether these findings
apply directly to CMFT, although another study has shown that MFT calcined at 1000
o
C
had very little pozzolanic activity
25
.
21
INSA, 2002.
22
NKL, 2002, p. 5-3.
23
INSA, 2002.
24
Wong et.al., 2002, p. 6.
25
Wong et.al., 2002, p. 8.
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The oil and sands industry suggests that the advantages of producing CMFT for use in
concrete instead of MK include: elimination of mining costs, availability of partially
processed product, and use of vast quantities of waste product. This industry foresees
transportation costs, capital investment, and market forces to be the main hurdles.
26
4.2. Performance in Concrete as an SCM
Generally, MK improves most mechanical and durability properties of concrete, and thus,
CMFT is expected to exhibit similar benefits. However, the properties of both MK and
CMFT, and their performance in concrete, will be affected by the calcination temperature
(see section 4.1).
27,
28
To achieve the full benefits of using MK as an SCM in terms of improved concrete
properties, INSA experience shows that MK must replace at least 15-20% of the cement,
particularly when the material is not pure, as is the case with CMFT
29
. Wong et.al., 2002,
suggest that replacement levels in excess of 15% for both MK and CMFT would be
required for full removal of the calcium hydroxide formed during the hydration of
cement
30
.
The high specific area of MK relative to that of both Portland cement and fly ash
increases the rate of concrete strength development. This property may be beneficial in a
ternary blend of Portland cement, FA and MK, where the use of FA typically results in
lower rates of strength development. The drawback of this feature of MK is that it also
increases the water demand and the consumption of air-entraining agent, and reduces the
workability of concrete
31,
32
. Furthermore, to counteract the detrimental effects of
increased water demand, chemical admixtures (water reducing admixtures and/or
superplasticizers) may need to be introduced, thereby increasing the costs of a concrete
mix
33
. Additional work is required to ascertain these properties for CMFT, since it is a
somewhat different material from pure MK. For example, one study showed that the
specific surface of CMFT was nearly 2.5 times that of pure MK
34
.
MK has historically been used in similar concrete applications with similar performance
results as silica fume (SF). CANMET study has shown that MK concrete may require
less superplasticizer and have slightly better constructability characteristics (e.g.,
finishability) than SF concrete
35
. However, Wong et.al., 2002, indicate that research into
CMFT usage as a pozzolan is still in its infancy
36
.
The NLK study suggests that by replacing a portion of the cement in a concrete mix with
MK, the total cementitious material content can be reduced, thereby reducing the
economic impact of using this high-priced SCM on the price of the concrete mix
37
.
While this may be a feasible option for pure MK, which has a pozzolanic reactivity of
26
Ted Lord, Syncrude, January2003.
27
Benoit Fournier, CANMET October 2001 presentation of Zhang and Malhotra, 1995
results.
28
University of Calgary and Syncrude, October 2001.
29
INSA, 2002.
30
Wong et.al., 2002, p. 3.
31
NLK, 2002, p. 4-5 to 4-6, and 4-8.
32
Wong et.al., 2002, p. 2.
33
AMEC, 2003.
34
University of Calgary and Syncrude, October 2001.
35
Benoit Fournier, CANMET presentation of Zhang and Malhotra, 1995 results.
36
Wong et.al., 2002, p. 9.
37
NLK, 2002, p. 4-9
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1.15 compared to Portland cement
38
, INSA does not recommend this approach, especially
without concrete trial tests
39
. Furthermore, as indicated in Section 3.1, CMFT are only
85-90% as efficient as pure MK, bringing their pozzolanic reactivity down to the Portland
cement level.
Colour is also an issue: unlike pure MK, which is almost white, CMFT is medium to dark
grey, depending on the extent of carbonation, since the material becomes lighter with the
increasing calcination temperature
40
. The whiter the MK, the more valuable it is, and the
easier its introduction in the concrete industry
41
.
Other properties that tend to improve when MK is used include: resistance to sulphate
attack and alkali-silica reaction (ASR)
42
, durability under freezing and thawing
conditions, and resistance to cracking and surface deterioration
43
.
5. Economic Evaluation
5.1. Cost of Production of CMFT
5.1.1. Cost of Extraction of MFT
Syncrude is currently involved in a consortium conducting a three-year research study
between the oil sands operators, the University of Alberta and CANMET in Devon,
Alberta. This research is focused on the extraction of commercial grades of MFT-kaolin
as a value added resource. The study, which will demonstrate the technical and economic
feasibility of this process, will cost approximately $250,000.
5.2. Cost of Testing CMFT for Use as SCM
CANMET is often involved in testing of new materials for use in concrete. They
estimate that a study to optimize the MK content in concrete with respect to strength and
cost of concrete would cost in the order of $30,000. A performance-testing program at
CANMET of CMFT as an SCM in concrete was estimated to last approximately a year
and a half and cost in the order of $200,000.
44
5.3. Cost of Transportation
Remoteness of the Alberta oil sands is another major challenge for developing the CMFT
as an SCM for use in concrete. The NLK study indicates that transportation costs from
the production site at Fort McMurray to the market may range from $90 to $120 per
tonne of CMFT, depending on the size of production, total transport distance, and
availability of bulk transport
45
. This alone represents a major disadvantage for CMFT
compared to PC, which is typically produced near the market, or FA, which is produced
in the Edmonton region. FA also has a developed market, which allows the users to take
advantage of bulk transport. The distances between Fort McMurray and potential
38
AMEC, 2003.
39
INSA, 2002.
40
Figure in January 22, 2001 letter from George Jones
41
INSA, 2002.
42
Wong et.al., 2002, p.1
43
NLK, 2002, p. 4-6 and 4-7.
44
Personal Communication, Nabil Bouzoubaâ, CANMET, July 10, 2003.
45
NLK, 2002, p. 3-4.
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markets (including off shore markets) for CMFT as an SCM in concrete are illustrated on
Figure 4.
Figure 4: Distances between Production Site and Potential Market for CMFT
5.4. Demand vs. Cost vs. Price
The EcoSmart initiative on this source of MK has furthered the understanding of the
circular relationship between the demand, the cost and the price of CMFT. This point is
best illustrated by Figure 5 and Table 2.
Figure 5: Relationship between Demand, Cost and Price of CMFT
Vancouver
Prince
Rupert
Calgary
Fort McMurray
VancouverVancouver
Prince
Rupert
Prince
Rupert
CalgaryCalgary
Fort McMurrayFort McMurray
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Figure 5 demonstrates that Production Size (Supply) determines the Cost; the Cost of
production with the desired rate of return on investment plus transportation cost
determine the Price; and the Price of the product determines the size of the market, or the
Demand. However, in the end, the Demand drives the Supply, sets the Price, and
ultimately determines the Cost. If the Cost relative to the Price returns a favourable
interest on the investment, the feasibility of a venture is determined. The producer (in
this case either the oil sands industry or a third party) then decides if the rate of return
meets their expectations. Indeed, the ultimate variable in this “equation” – whether to
proceed with the venture or not – is the producer’s willingness and desire to take the risk
of making the initial investment. Table 2 presents several options for CMFT production
based on the NLK and Tynebridge studies.
Table 2: Relationship between Demand, Supply, Cost and Price of CMFT
Relative Size of
CMFT Production
Plant
Demand
(tonnes / year)
Supply
(tonnes / year)
Cost
($ / tonne)
Price*
($ / tonne)
N/A 0 N/A N/A 650-680
(current
price of
MK)
Smallest
(Tynebridge)
0 22,000 167 600
Smallest (NLK) 20-24,000 37,000 114 303
Medium 39,000 74,000 72 282
Large (based on a
given Price that sets
the Demand)
200,000 N/A N/A 130
Large (based on a
given Supply that
determines the
Price)
N/A 1,000,000 29 142
* Includes transportation costs, assuming delivery within Western Canada and North-
Western States
In summary, at the current price of MK ($650-680/tonne, which is comparable to the
price of silica fume) the demand for CMFT is virtually nil. There are four main reasons
for this:
1. the product is inferior to MK in its properties as an SCM, including its colour,
2. the demand for high-performance, white MK as an SCM is presently small and
the supply of pure MK is sufficient to meet the current demand,
3. the price in the best case scenario would be similar to Portland cement and
higher than FA, and
4. if CMFT aims to supply the demand for lower grade SCM, it cannot compete
against FA, which can be produced at near zero cost, without additional
processing, closer to the market, and with negligible environmental impact
associated only with its transportation.
At the $600/tonne price level as determined by the Tynebridge study for 22,000 tonnes of
CMFT supply annually, the demand can be assumed to be nil as well (for the same
reasons as above).
The NLK study calculates the price of $303/tonne for the production of 37,000
tonnes/year. The demand at this price within Western Canada by the concrete industry is
estimated at 20-24,000 tonnes. At the slightly lower price of $282/tonne when
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 13
production is doubled to 74,000 tonnes/year, the demand is estimated to increase to only
39,000 tonnes/year. The balance of the supply would need to find other markets (e.g.,
paper, tires, etc.) or the geographical market would have to be expanded (but this carries
additional transportation cost implications).
A production level of 1,000,000 tonnes/year lowers the price of CMFT to $142/tonne.
This production level assumes an extensive market for CMFT, both in the type of
application and geographical extent.
Since MK is currently used only in specialty concrete products, such as ultra strength
concrete, the price of MK is relatively very high and the market for MK is relatively
small. To create a large enough demand to keep the cost down and make the venture
profitable for a producer, the price of CMFT for use in concrete will have to be at most at
the level of Portland cement, if not lower. In Western Canada, the price of CMFT would
have to be at most $130/tonne. Therefore, based on a market analysis curve provided by
the NLK study in Figure 6, this price is expected to generate a demand for 200,000
tonnes/year. Detailed assumptions for these numbers may be found directly in the two
studies referenced.
Figure 6: Market Analysis Curve: Price vs. Demand
46
In the best case scenario, with the demand for CMFT at 220,000 tonnes/year at the
$130/tonne price comparable to PC in Western Canada, extraction of the corresponding
amount of MFT from the tailings ponds (approximately 11 million tonnes of tailings,
assuming tailings contain 10% clay, of which about 20% could be converted to CMFT
47
)
would not satisfy the need of the oil sand operators to clean up their tailings ponds. As
indicated in Section 3, there is potential to produce 6 million tonnes of CMFT per year.
The current SCM market could absorb a maximum of 220,000 tonnes of CMFT per year,
much less than the 6 million tonnes that could be produced.
The lower reactivity and darker colour of CMFT than of MK makes the value of CMFT
more comparable with that of FA. However, CMFT cannot compete with FA for the
following reasons:
• the production of FA in Alberta already exceeds the demand,
• the price of FA (FOB) at a power plant in Alberta is low (from $8 - $12 / tonne),
• FA does not require additional processing,
• FA is closer to the market, and
• the GHG benefit in concrete is greater with FA.
46
NLK, 2002, p. 2-9.
47
NLK, 2002, p. 4-3.
0
200
400
600
0 50,000 100,000 150,000 200,000
MK Demand (tonnes/year)
MK Price ($/t)
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 14
The use of yet another SCM by the ready-mixed concrete supplier requires additional
cost for a separate silo for CMFT.
Therefore, unless drastic change occurs in the current price or quality of FA, CMFT will
have difficulty penetrating the SCM market.
6. Environmental Evaluation
The NLK report calculated the CO
2
impact of using CMFT as an additional SCM in a
concrete mixture containing 300 kg/m
3
total cementitious materials content and 25% fly
ash (by weight), i.e., Portland cement at 225 kg/m
3
and fly ash at 75 kg/m
3
. NLK
suggested that by using CMFT as an additional SCM, the total cementitious materials
content could be reduced by up to 10%. However, the validity of this approach is
questioned by INSA
48
.
As an example, the CO
2
signature of concrete would be decreased by amounts in the
order of 0.08-0.20 tonnes/m
3
of concrete as a result of using 10% CMFT (by weight) in
the concrete mixture, for total cementitious materials contents reductions of 0-10%,
respectively
49
. This reduction may be compared with the CO
2
signature reduction of 0.13
tonnes per cubic meter of concrete when cement is replaced by an additional 10% fly ash
(i.e., in addition to the 25% already replaced in the baseline mix). Therefore, it is evident
that unless the total cementitious materials content is reduced (by at least 6%, according
to these calculations), there is no CO
2
advantage to using CMFT.
The NLK analysis assumes that 0.9 tonnes of CO
2
are generated per tonne of Portland
cement produced, and that the CO
2
emissions associated with the production of fly ash
are accounted for by the power generation sector, thus, only transportation-related CO
2
emissions need to be considered. The study calculated that 0.37 tonnes of CO
2
would be
generated per tonne of CMFT produced, and that transportation-related CO
2
emissions
would be in the order of 0.02 tonnes per tonne of CMFT delivered to the Vancouver
market
50
. The transportation emissions can be assumed to be roughly the same for
CMFT and FA transported from northern Alberta to south-western British Columbia.
Other environmental benefits of developing CMFT from the oil sands industry include:
• reduction of the volume of the tailings ponds;
• improved settling properties of tailings ponds for process water recovery; and
• improved oil recovery efficiency from the tar sands (if the 2% residual bitumen
is recovered from the tailings)
51
.
Some of the detrimental environmental impacts of this initiative include:
• additional natural gas requirements for the calcination and drying processes
(note: CO
2
emissions from the burning of this fuel have already been
incorporated in the calculations of the CO
2
signature of concrete containing
CMFT);
• some additional emissions of other contaminants from the calcination and drying
processes, e.g., CO, NO
x
, N
2
O, SO
2
, CH
4
, PM (filterable);
• emissions from transportation of CMFT from source to user (note: CO
2
emissions from the transportation of this material have also already been
included in the CO
2
signature of CMFT concrete)
52
.
48
INSA, 2002.
49
NLK, 2002, based on data used to generated graph on p. 5-9.
50
NLK, 2002, p. 5-10.
51
NLK, 2002, p. 5-9 and 5-10.
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EcoSmartMKReport 15
7. Summary of Findings
7.1. Properties of Various SCMs and PC
Examination of the various aspects of CMFT extraction, processing, and potential use as
an SCM in concrete can be summarized and the properties compared with those of other
SCMs and PC. Table 3 presents a summary of the main aspects that can be used for
comparison.
Table 3: Comparison of the Properties of Various SCMs and PC
Property CMFT MK SF FA PC
Performance Factor
(approximate
PC)
(a)
1.10 1.15 1.25 0.85 1.00
Colour Medium to
Dark
White Dark Light to
Medium
Medium
Cost in BC (on the
market) ($ / tonne of
product)
(unknown) $400 -
$600
$400 -
$600
$8 (at the
Alberta
plant)
$75 (with
transport)
$130-$150
Availability (in
Canada)
(tonnes/year)
Potentially: 6
million
53
Currently: for
small
laboratory
tests only
(unknown,
but
abundant)
20,000
54
2,200,000
55
14,000,000
capacity
CO
2
Generated by
Production (tonnes
CO
2
/ tonne of
product)
0.37 0
(b)
0 0 0.9
CO
2
Saved by
Partial Replacement
of PC (tonnes CO
2
/
tonne of product)
0.53
(0.37-0.9)
0.9 0.9 0.9 N/A
CO
2
Saved by
Partial Replacement
of PC (tonnes CO
2
/
m
3
of concrete)
0.08-0.20
(c)
0.13 0.13 0.13
(d)
N/A
(a)
Factors used in the work by Popovic
56
(b)
Emissions attributed to mining industry
(c)
10% CMFT in addition to 25% FA, total cementitious material content reductions by
0-10%
57
(d)
Additional 10% FA in addition to 25% FA
52
NLK, 2002, p. 5-10.
53
NLK, 2002, p. 4-3.
54
Bouzoubaâ and Fournier, 2003, p. 31.
55
Bouzoubaâ and Fournier, 2003, p. 31.
56
AMEC, 2003.
57
NLK, 2002, based on data used to generated graph on p. 5-9.
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 16
7.2. Benefits of CMFT Production and Usage as SCM
It has been shown that it is technically feasible to produce CMFT from the oil sands
tailings ponds. The benefits associated with the production of CMFT and its use as an
SCM in concrete include:
• extracting MFT from tailing ponds would allow oil sands operators to recover
the limited process water, reduce the size of the tailings ponds, increase the
capacity of the tailings ponds for future operations, and reduce the risk of a
breach in the banks containing the tailings ponds;
• the use of this by-product would displace the need for mining virgin material;
• there are huge reserves of this by-product in Canada; and
• use of CMFT as an SCM in concrete has GHG reduction potential.
7.3. Drawbacks of CMFT Production and Usage as SCM
The drawbacks associated with the production of CMFT from oil sands operations and its
use as an SCM in concrete include:
• CMFT is not the same as MK;
• the performance of CMFT as an SCM is inferior to that of MK, rather, it is more
comparable to FA;
• CMFT is a low-value product due to its dark colour;
• the transportation costs are high;
• capital investment is needed to initiate commercial production;
• the resistance of the construction industry needs to be overcome;
• CMFT cannot compete against fly ash; and
• the current SCM market is not large enough to generate the economies of scale
required to keep the price down.
8. Conclusions
8.1. General
Calcined mature fine tailings (CMFT) are a material with similar but inferior properties
to pure metakaolin (MK).
CMFT is dark in colour, which makes it a low-value product in most of the potential
markets identified to date (e.g., white concrete products, paper). It is less reactive than
pure MK (85-90% effectiveness), approximately as reactive as Portland cement, and only
somewhat more reactive than fly ash (FA) (18% more reactive). It is more energy and
labour intensive to produce than FA, where both materials are by-products of industrial
processes. Its energy intensity also makes CMFT less environmentally beneficial than
FA. Finally, under current market conditions, CMFT is at least four times more
expensive than FA.
The demand for MK, particularly CMFT, in Western Canada is not sufficient to justify
the capital expense of developing this SCM. However, the worldwide demand for SF and
the insufficient supply may provide the market needed to economically develop CMFT.
58
Additional research into the use of MK, and more specifically CMFT, is required to
determine the optimum temperature for calcination, the long-term performance in
58
Personal Communication, Phil Seabrook, Levelton, September 19, 2001. Comments
on NLK, 2002 report.
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 17
concrete, and quality control requirements and procedures
59
. Also, more information is
needed for the ready-mixed concrete producer as the user of CMFT, such as the price,
availability, additional testing requirements, risk management options, etc.
60
8.2. Oil Sands Industry
The oil sands industry is not interested in going into this venture if there is no identifiable
market for the CMFT product
61
. Their main interest presently lies in recovering the
process water for reuse in the operations. If the water recovery process generates a
concentrated and practical MFT as a by-product, it would be made available for further
processing by an interested third party. They consider production of CMFT as a
synergistic approach to fine tailings management, water recovery, environmental
protection, and waste product commercialization
62
.
The oil sands industry is interested in producing a new batch of MFT (uncalcined,
calcined, or partially calcined) for testing at a laboratory, such as CANMET, and for
experimenting at an interested ready-mixed plant.
8.3. Cement/Concrete Industry
The cement and concrete industry are not presently interested in taking on the
development of CMFT as an SCM. They would be willing to consider using CMFT if
the oil sands industry can provide the product at no cost at their plants. This industry also
raised the concern that presently there is no market for this material in concrete
applications or the ready-mixed concrete industry, and that the investments required to
make MK a viable SCM could be better spent elsewhere to reduce the CO
2
footprint of
concrete
63,
64,
65
. In addition, as was the experience with developing FA as an SCM,
specifiers and end users would have to be persuaded of the benefits of CMFT and would
have to be willing to accept any associated risks. As a rule, most Canadian industry
specifiers defer to CSA specifications when designing their projects. As such, there may
be a further hesitance to use MFT-based metakaolin, as it is not derived from a pure
natural kaolinite clay source
66
.
8.4. EcoSmart Concrete Project
The EcoSmart Concrete Project has ascertained that producing CMFT from the oil sands
industry is feasible, provided that all MK markets can absorb this product, including the
concrete, paper, tire, etc. markets. However, based on its mandate, EcoSmart’s focus is
only on the SCM application, and EcoSmart may revisit this application pending the
outcome of the investigation of the oil sands industry into other applications.
59
University of Calgary and Syncrude, October 2001.
60
Personal Communication, Phil Seabrook, Levelton, September 19, 2001. Comments
on NLK, 2002 report.
61
John Oxenford, Syncrude, January 14,2003.
62
Ted Lord, Syncrude, January 2003.
63
Personal Communication, Jim Caruth, Pozzolanic, October 11, 2001. Comments on
NLK, 2002 report.
64
Personal Communication, Ron Sills, Lehigh Inland Cement, October 11, 2001.
Comments on NLK, 2002 report.
65
Personal Communication, Tom Gibson, Lehigh Northwest Cement, September 23,
2001. Comments on NLK, 2002 report.
66
Personal Communication, Paul Masson, Lafarge Canada, January 14, 2003.
Metakaolin meeting.
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 18
9. Future Work
9.1. EcoSmart
Based on the findings in this study, it is recommended that no further work be done by
the EcoSmart™ Concrete Project on developing CMFT as an SCM at this time. When an
improved and feasible product is developed by the oils sands industry and research
community, it is recommended that EcoSmart initiate a case study project using this
material.
9.2. Research Community
CANMET, the University of Alberta, the University of Calgary, and other interested
parties are continuing their research work on the extraction of this source of kaolin. It is
also recommended that research be continued on the use of CMFT in concrete, to bring
the knowledge about the performance of CMFT to the level of other SCMs such as FA,
SF and MK. The oil sands industry should provide samples as required.
9.3. Oil Sands Industry
The oil sands industry is continuing to investigate economical ways to clean up the
tailings ponds, and conducting research into the extraction of quality kaolin that could be
used to produce quality CMFT, comparable to pure MK. Other uses for the MFT and
CMFT will be investigated, along with continuation of investigations into other third
party groups interested in producing CMFT. The oil sands industry will also try to find a
way to reuse the process water from the tailings ponds instead of continually drawing on
fresh water and increasing the size of the tailings ponds. This study will be completed by
2005.
9.4. Concrete Industry
Once successful results from the oils sands industry are established, the ready-mixed
concrete producers should experiment with CMFT in concrete and gain confidence in the
use of this SCM. The oil sands industry should provide sufficient samples to the ready-
mixed concrete producers for testing. It is further recommended that the concrete
industry adopt this material as an alternate SCM once the oil sands industry and the
research community have advanced the knowledge and quality of this material.
10. References
ACI Manual of Concrete Practice. ACI International. 2003.
AMEC Earth & Environmental Limited (Rusty Morgan). “Metakaolin Review Meeting
Edmonton – January 14, 2003: Summary of Presentation.”
Bouzoubaâ, N. Research Scientist, ICON/CANMET. [email protected]
Bouzoubaâ, N. and Fournier, B. "Current Situation of Supplementary Cementitious
Materials (SCMs) in Canada." CANMET Report MTL 2003-4 (TR), Natural
Resources Canada, Ottawa, April 2003.
Caruth, Jim. Formerly Fly Ash Manager, Pozzolanic International Limited (presently
with Lehigh Northwest Cement Limited). [email protected]
Fournier, B. Program Manager, Concrete Technology Program, CANADA.
“Presentation of Zhang and Malhotra, 1995 Results”, EcoSmart™ Metakaolin
Meeting, Edmonton – October 16, 2001.
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 19
INSA (Pera, Jean). “Analysis of the NLK Project EA 2860 – EcoSmart™ Concrete
Project Metakaolin Pre-Feasibility Study.” December 2002.
Lord, Ted. Syncrude Canada. Presentation on “Kaolin Clay Derived from Oil Sands
Fine Tailings – The Syncrude Perspective” to EcoSmart at Metakaolin
Stakeholder Meeting in Edmonton, Alberta, January 14, 2003.
Lord, Ted. Syncrude Research. (780) 970-6907, [email protected]
Malhotra, V.M. May 1999. “Making Concrete ‘Greener’ with Fly Ash.” Concrete
International, Vol. 21, no. 5, pp. 61-66.
Masson, Paul. Lafarge Canada Inc. (403) 225-5424, paul.masson@lafarge-na.com
NLK Consultants Inc. “EcoSmart Concrete Project Metakaolin Pre-Feasibility Study.”
September 2002.
Pope, Brad. Manager of Marketing and Technical Services, Pozzolanic International
Limited. (604) 946-3842, [email protected]
Omotoso, D., Hamza, H., Oliver, J. and Lord, T. Presentation by CANMET AST,
Devon, Alberta Research Council, and Syncrude Research on “Kaolin in Oil
Sand Tailings” to EcoSmart at Metakaolin Stakeholder Meeting in Edmonton,
Alberta, October 16, 2001.
Oxenford, John. Manager, Research Programs, Edmonton Research Centre, Syncrude
Canada. (780) 970-6810, [email protected]
Sills, Ron. Regional Marketing Manager, Lehigh Inland Cement.
Tynebridge Technologies Limited. “Syncrude Kaolin Recovery Project.” September
1998.
University of Calgary and Syncrude Canada. Research Update Presentation on “Potential
Use of Metakaolin from Oil Sand Tailing in Concrete.” October 16, 2001.
Wong, R.C.K., Gillott, J.E., Thomas, M.J., and Poon, C.S. “Calcined Oil Sands Tailings
as a Pozzolanic Admixture for Concrete.” Submitted to Cement and Concrete
Research for publication in November 2002.
11. Appendices
The appendices to this report are prepared separately from this document, and are
available at www.ecosmart.ca.
Appendix 1: AMEC Earth & Environmental Limited (Rusty Morgan). “Metakaolin
Review Meeting Edmonton – January 14, 2003: Summary of Presentation.”
Appendix 2: Bouzoubaâ, N. and Fournier, B. "Current Situation of Supplementary
Cementitious Materials (SCMs) in Canada." CANMET Report MTL 2003-4 (TR),
Natural Resources Canada, Ottawa, April 2003.
Appendix 3: EcoSmart Concrete Project, Minutes of Metakaolin Meeting in
Edmonton, October 16, 2001.
Appendix 4: EcoSmart Concrete Project. Minutes of Metakaolin Meeting in
Edmonton, January 14, 2003
Appendix 5: Fournier, B. Program Manager, Concrete Technology Program,
CANADA. “Presentation of Zhang and Malhotra, 1995 Results”, EcoSmart™
Metakaolin Meeting, Edmonton – October 16, 2001.
EcoSmart™ Metakaolin Study – Report for Action Plan 2000
EcoSmartMKReport 20
Appendix 6: INSA (Pera, Jean). “Analysis of the NLK Project EA 2860 –
EcoSmart™ Concrete Project Metakaolin Pre-Feasibility Study.” December 2002.
Appendix 7: Lord, Ted. Syncrude Canada. Presentation on “Kaolin Clay Derived
from Oil Sands Fine Tailings – The Syncrude Perspective” to EcoSmart at
Metakaolin Stakeholder Meeting in Edmonton, Alberta, January 14, 2003.
Appendix 8: NLK Consultants Inc. “EcoSmart Concrete Project Metakaolin Pre-
Feasibility Study.” September 2002.
Appendix 9: Omotoso, D., Hamza, H., Oliver, J. and Lord, T. Presentation by
CANMET AST, Devon, Alberta Research Council, and Syncrude Research on
“Kaolin in Oil Sand Tailings” to EcoSmart at Metakaolin Stakeholder Meeting in
Edmonton, Alberta, October 16, 2001.
Appendix 10: Tynebridge Technologies Limited. “Syncrude Kaolin Recovery
Project.” September 1998.
Appendix 11: University of Calgary and Syncrude Canada. Research Update
Presentation on “Potential Use of Metakaolin from Oil Sand Tailing in Concrete.”
October 16, 2001.
Appendix 12: Wong, R.C.K., Gillott, J.E., Thomas, M.J., and Poon, C.S. “Calcined
Oil Sands Tailings as a Pozzolanic Admixture for Concrete.” Submitted to Cement
and Concrete Research for publication in November 2002.
