One niche market is gaining more
and more attention from the industrial minerals industry: that
of carbon dioxide (CO2) sequestration or storage,
which aims to reduce greenhouse gas (GHG) emissions into the
Carbon capture and storage (CCS) is
the process of capturing, transporting and storing
anthropogenic CO2. The CO2 is sequestered
from large industrial sources such as coal, oil and gas
facilities before it is released into the atmosphere. It is
then transported through pipelines - similar to those used to
transport natural gas and oil - and permanently stored in
reservoirs or in other deep geological formations. The selected
storage sites are at depths of 1-5km below the surface and
exhibit the geologic conditions necessary to ensure that these
reservoirs can retain the CO2 for long periods of
time. Small volumes of CO2 can also be transported
as a liquid in ships, tanker trucks or rail tankers.
Carbon capture and storage is of
increasing interest to the raw materials industry as industrial
minerals rich in magnesium oxide (MgO) and calcium oxide (CaO)
- including brucite, olivine and wollastonite (see
table) - are naturally capable of sequestering
CO2 before transforming the gas into a geologically
and thermodynamically stable form, ie. carbonates, that can be
Olivine for instance, once milled
to expose additional surface area, breaks down in a few years
to form carbonates through the carbonation process. This
process of chemical weathering can be enhanced to increase
CO2 sequestration and suggests that olivine and
other similar minerals, once crushed and spread on fields to
expose them to high levels of anthropogenic CO2,
could be used to pick up carbon dioxide from the atmosphere in
addition to supply essential magnesium, calcium, silica and
iron to the growing plants.
Much of the research into mineral
carbon sequestration has looked at methods of speeding up the
carbonation process, which is inherently slow under natural
conditions, to create an industrially viable system owing to
the global reserves of suitable minerals.
The minerals can be processed to
particle sizes of less than 100 microns to expose a high
surface area for faster reaction that improves carbonation
rates. The resulting carbonated products could provide a useful
source of additional revenue, as they can be used in
construction applications or mine reclamation.
Minerals proposed for carbon sequestration
Source: George Hawley, consultant, George C. Hawley
Magnesium oxide is said to be more effective in reacting with
CO2 than calcium oxide as, in theory, one tonne of
brucite (containing MgO) can capture 0.75 tonnes of
CO2 while CaO-bearing wollastonite will sequester a
lower amount of 0.38 tonnes.
Sources of MgO, which is used in
basic refractories, could therefore be seen as good potential
materials for CCS. But at present, the application does not
seem to have yet attracted the attention of producers.
It is something that we have
been aware of however it is not something that we are following
with any great interest, just watching, a world-leading
magnesia producer told IM.
Basically we do not think the
science is developed well enough for this application to figure
in our current strategic marketing plan, the producer
Brucite, a natural magnesium
hydroxide mineral which has a content of 69.1% MgO, could be
seen as a good choice. Carbonate-hosted brucite deposits of
economic significance are found in Canada, Norway, Russia, and
the USA. Undeveloped or exhausted brucite deposits occur in
Arizona, USA; British Columbia, Canada; China, Ireland, North
Korea and the UK.
The white colour of brucite is an
advantage as the magnesium carbonate produced from the reaction
with carbon dioxide tends to be white, and thus could be
suitable for use as a white extender pigment to compete with
Newly-formed International Brucite
Corp. (IBC) became North Americas leading producer in
November 2010 following the bankruptcy of the deposits
former developer, Applied Chemical Magnesias Corp. (ACM), in
Olivine, with 45-51% MgO content, technically has a good
potential for CCS as it breaks down in a few years to form
carbonates when crushed and exposed to CO2.
World capacity in 2008 totalled
about 9m. tpa but actual output could be as low as 6.5m. tonnes
at present. The main producer is Norway, followed by Japan and
Globally, the largest olivine
producer is Norway-based Sibelco Nordic (formerly North Cape
Minerals A/S) whose three olivine mines in Norway - Aheim,
Bryggja and Raubergvik - have a combined capacity of 2.4m.
However, olivine price remains a
source of concern. A lot of people are asking about the
use of olivine in CO2 sequestration. But it is not
moving yet, a leading world producer of olivine commented
According to the Faculty of
Geosciences at Utrecht University in the Netherlands, about
140g olivine is needed to sequester 176g CO2. In a
report, the university recommend to spread large quantities of
milled olivine over the Earths surface.
To remove 1bn tonne of
CO2, 0.5% of the land surface (just over 5% of
Siberia) should be covered by a 0.4mm thick layer of olivine
grains, preferably by mixing them with fertilisers before
spreading, the university suggested.
A source from the industry
commented to IM that the use of olivine in a
country hosting the mineral could be possible as there would
not be much freight cost involved. Otherwise it would not
be worth it if the mineral has to be transported to be used for
CO2 sequestration, the source declared, adding
that freight prices to transport minerals have significantly
As reported by IM,
olivine prices have shown signs of increasing. Prices currently
range at $60-90/tonne but some prices were reported at up to
$100-200/tonne depending on the grade, meaning that it is not
economically viable to use the mineral.
At some point CO2
sequestration could have a great potential, perhaps within the
next 10 years. It is just a question of training the
industry, the source told IM.
US carbon dioxide emissions growth*
Source: Short-term energy outlook, September 2011,
* Change from previous year
Dunite, which is about 50% olivine and 50% serpentinite, is
increasingly used in refractory applications but could also be
used for CCS. The mineral is produced by Pasek SA in Galicia,
Dunite is a natural candidate
due its capability to react with CO2, fixing it as
bicarbonate as first step of dissolution of
CO2, Roberto Caballero, manager of
Paseks new division Pasek Technical Center (PTC), told
IM, adding that CCS is a new opportunity
for some industrial minerals such as dunite. As for all
mineral candidates for CCS, particle size and reaction
parameters such as pressure and temperature have a strong
Today, there is no dunite produced
for CCS but Pasek is pushing dunites CCS potential
from R&D and sales departments. Caballero revealed
that Pasek is in contact with several companies interested in
minerals for CCS.
We hope to start supplying as
soon as possible, Caballero said.
Wollastonite, thanks to its 48.3% CaO content, could be used in
CCS as it is high in purity. Although it is theoretically only
about half as efficient as brucite in sequestering
CO2, wollastonite is much more widely available.
According to the US Geological
Survey, estimated wollastonite crude ore production increased
in 2010 and was in the range of 550-575,000 tonnes in 2010
compared with 520-540,000 tonnes in 2009. The main producers
are China (300,000 tonnes in 2010), India (145,000 tonnes), the
USA (65,000 tonnes in 2009), Mexico (40,000 tonnes), Finland
(16,000 tonnes in 2009) and Spain (7,000 tonnes in 2009).
In addition, the by-products from
sequestration should be marketable and of reasonably high value
as wollastonite reacts with sulphuric, carbonic and
hydrochloric acids to produce calcium sulphate (gypsum),
calcium carbonate (calcite) and calcium chloride, respectively.
The first two are insoluble; calcium chloride is soluble and
will pass out in the liquid wastes.
Wollastonite can also remediate
flue gases containing sulphur, chlorine and carbon
NYCO Minerals Inc., a USA-based
leading producer of chemically modified wollastonite, believes
that wollastonite is being given serious
consideration as a material to be potentially used in the
[It] has been reported to be
one of the most reactive minerals in this process and the
availability of both calcium and silica from wollastonite are
of particular interest in the CCS process, NYCOs
technical marketing manager Sal LaRosa told
However, LaRosa pointed out that
the market potential for wollastonite is still in the
development stage and a commercial opportunity is not yet
If the conversion process
proves to be commercially viable, the potential for
wollastonite in this market could be significant, he
said, underlining that the development of the CCS process
will depend on cost, economics and the ability to create a
material out of the CCS process that has value.
As a consequence, NYCO which
is aware of the potential use of wollastonite in
CCS, plans to continue working with companies that have
an interest to evaluate wollastonite for this
Limestone in FGD
Many industrial applications, such as coal-fired power
stations, require the combustion of hydrocarbons and thus emit
sulphur dioxide (SO2) into the atmosphere. Other
processes, such as the incineration of waste, also generate
SO2 and other acidic gases such as sulphuric,
sulphurous and hydrochloric acids which increase the acidity of
the atmosphere and promote acid rain.
Limestone remains an important
mineral in the flue gas desulphurisation (FGD) market, as it is
used with lime to sequester SO2, which in many cases
produces gypsum as a by-product. About 600kg limestone is
needed to capture 1 tonne SO2, and generates almost
two tonnes of gypsum as a by-product.
Flue Gas Treatment (FGT) represents
the second largest market of the turnover of Carmeuse Group,
the world-leading limestone producer headquartered in
This market is an important
market, aligned with our target to be a reference supplier with
full technical support for our customers, Carmeuse CEO
Rodolphe Collinet told IM.
As Carmeuse explained, limestone
is the preferred sorbent and will remain in the
future owing to the volume needed, the proven
calcium-based technology and the limestone availability.
FGD market needs proven,
efficient and reliable solutions to comply with legislation
without risk. The technology is looking more like an evolution
than a revolution, Collinet said.
North America and Europe are
important markets for FGD. Although legislation is slightly
different, the goal and the customers needs are
comparable, Collinet believes. Volumes and logistics are
different because of local realities such as limestone
availability, the coal share in electricity production and the
Collinet believes that global FGD
market should be growing in the coming years in some regions
such as Eastern Europe or mid-west USA and in countries with a
strong growth potential.
This is highly dependent on
the coal share use in electricity. This topic is highly
strategic at state level in terms of mix, cost and safety of
electricity supply, Collinet commented.
In Jamaica, limestone producer
Lydford Mining Co. Ltd told IM that the
company, which focuses on whiting grade, high bright limestone
for paints, plastics, fillers and high purity limestone used in
food and pharmaceutical grades of limestone is entering the
market for FGD in coal-fired power stations.
We have the criteria in
place: quality limestone, port, shipping, and an expanding
market for FGD, explained CEO Leo Cousins, adding:
It is worth it if you gear for quantity and put the
equipment for volume output in place - 500,000 tpa to 1m.
In 2010, Lydford exported about
80,000 tonnes into the USA in partnership with TBS shipping
from New York, which operates a bulk carrier fleet of ships.
The company loads in 40,000-tonne carriers from the port of
Ocho Rios in Jamaica, discharging into barges at the port of
As Cousins highlighted, limestone
is a very low-priced commodity with the current market price
between $8-14/tonne FOB. In this usage, the price paid is
based especially on the purity and reactivity of the limestone
for trapping carbon dioxide. Sizing, volumes, moisture content,
port fees and geographical location to user, are other factors
considered. The abrasiveness of the limestone is another factor
in the grinding costs to be incurred, Cousins
FGD is dependent on environmental
laws in each country so the growth is dependent on political
considerations, the main challenge being geography - ie. the
distance from user to producer - and logistics.
However, Cousins believes that
food grade, lime, cement, and construction aggregate will
always be more profitable than FGD economically
CCS is expected to play a significant role in decreasing
industrial CO2 emissions around the world.
The US Energy Information Administration (EIA)
estimates that CO2 emissions from combusting fossil
fuels increased by 3.9% in 2010. Forecast fossil-fuel
CO2 emissions are estimated to fall by 0.7% in 2011,
as emission increases from higher natural gas consumption are
offset by declines in coal and petroleum consumption. Increases
in hydroelectric generation and other renewable energy sources
in 2011 will also help to mitigate emissions growth.
emissions in 2012 are forecast to remain stable as expected
declines in coal emissions are nearly equalled by the increases
in emissions from petroleum and natural gas.
According to the International
Energy Agency (IEA), global demand for energy will continue to
increase. This will be driven by emerging economies and
continued global prosperity. Forecasts suggest a 50% increase
in global energy demand by 2030, meaning that we will need all
sources of energy to meet this demand. This includes a
continued role for fossil fuels including coal, oil and gas,
along with emerging energy sources such as wind, solar, and
management actions will be needed by both energy producers and
energy consumers as environmental stresses are growing,
particularly around CO2 and global warming.
All technologies along the CCS
chain have been in operation in various industries for decades,
although in relatively small scale. IEA explained that
these technologies have only been put together in
industrial scale in a small number of installations. No
large-scale installations exist yet in electricity
IEA analysis suggests that CCS will
play a vital role in worldwide, lowest-cost efforts to limit
global warming, contributing around one-fifth of required
emissions reductions in 2050.
For CCS to reach this
potential, around 100 CCS projects would need to be implemented
by 2020 and over 3,000 by 2050, IEA pointed out.
Although the application does not
seem to be a major concern for mineral industry players yet,
the amount of industrial minerals used in CCS could increase
accordingly in the future as a result of this emerging market.
However, the process would take time and would depend on
various factors such as mineral prices, freight, and the
development of the technology.
This capability was probably
investigated in the past but, today, it appears to be
necessary. In my opinion, the market for mineral sequestration
of CO2 will take a long time and process will be
slow, Caballero from Pasek commented to
Caballero believes that
reaction technology would be guided to a universal
solution at room conditions, for example a layer of
mineral covering the whole Earth as mentioned by the university
of the Netherlands. On the other hand, really difficult
reaction technology would be focused on high performance
reactors to get instant sequestration, he added.
CCS being directly related to the
energy market, one important factor will be political as the
increase of CCS will depend on environmental laws and
regulations to be voted on in the future, in Europe as in the
rest of the world.
CCS is not a long-term solution but a transitional
solution, as one mineral producer explained.