RHI’s subsidiary Dolomite Franchi is one of the
few refractory dolomite producers with 0.5m. tpa
dolomite mined in the north of Italy
Being directly dependent on the steel industry, refractory
dolomite was significantly impacted by the financial downturn
which led to a necessary downsizing of the installed
capacities.
About 20% of dolomite produced is
used for specific applications in the steel and cement
industries, the main 80% being used for construction. There are
also some applications for agriculture as soil correction, but
it represents a very small portion (see Dolomite at a
glance).
Since the major part of dolomite
goes into the steel industry, the ups and downs of the steel
sector are reflected in the development of dolomite and demand
shows a parallel curve to standard magnesia-based
refractories.
During the crisis, intermittent
operations reduced demand as people stopped using dolomite
owing to the risk of hydration if the kiln was stopped for a
long period of time.
Even if “the industry is not
back to business as usual,” as head of RHI-owned Dolomite
Franchi Spa plant Alessandro Romano told IM,
stainless steel markets have shown some pick up, driving up
dolomite consumption.
Similarly to many other branches,
the dolomite industry has strongly concentrated on
environmental issues. Whether it was new ecologic binders for
shaped dolomite refractories or modernised plant equipment in
order to minimise gas, dust and noise emissions, all these
measures made dolomite refractories a very advanced
state-of-the-art product for the steel industry.
Meanwhile some of the strict
measures could be released again. But the industry is not yet
back to the bright days of the 1990s.
However, the refractory world is
opening its eyes for this type of raw material and specifically
to the products made with it. It has very interesting
advantages like good and reliable performance in addition to
attractive lower costs.
“The tendency is to have an
increase in the consumption,” Mauricio Pinho, Magnesita
Refrat‡rios SA’s raw materials global director,
explained to IM.
Dolomite production, particularly
for aggregates, is extremely widespread but refractory grade
dolomite production is relatvely limited.
World refractory dolomite producers
include Magnesita Refrat‡rios SA (USA, China, Belgium,
France and Germany), Carmeuse North America, USA, Calcinor SA,
Spain, Vardar Dolomite, FYR Macedonia, and RHI AG’s
subsidiary Dolomite Franchi in Italy.
Dolomite Franchi
Italy’s Dolomite Franchi Spa, 100%-owned subsidiary of RHI
AG since 2007, produces high grade dolomite for secondary
metallurgy in Brescia, Lombardia, in the north of Italy.
Refractory products based on dolomite are used almost
exclusively in steel production. Because of their extremely low
rate of impurities, the bricks are used primarily in ladles
(90%). They are also used in AOD converters (10%); monolithics
are used as hearth ramming and repair mixes in the electric arc
furnace (50%) and for the lining of ladles and converters
(50%).
Founded in 1919, Dolomite Franchi
started production of dolomite blocks for lining in electric
arc furnaces (EAF) in 1952. The company, one of the few
globally active dolomite producers, owns its own operation and
plant in the city of Marone, near Lake Iseo, for the production
of refractories materials and end products such as bricks and
monolithics. Having been impacted by the financial crisis,
Dolomite Franchi produced 96,800 tonnes in 2009, including
59,500 tonnes bricks and 37,300 tonnes monolithics, down from
121,000 tonnes in 2008, with respectively 75,000 tonnes bricks
and 46,000 tonnes monolithics. Total sales revenue of the
company was Û34.5m. ($46.6m.) down from Û42.2m.
($57m.) in 2008.
The raw material is mined in
Galarusso, above Marone, since the old mining operation,
located directly in Marone, closed down in 1980.
At full capacity, the dolomite
factory operates in 20 shifts per week, 24 hours a day. The
refractories are mixed by three fully-automated mixers, pressed
by three hydraulic presses into various shapes and formats, and
then finished in two tempering kilns.
Dolomite Franchi supplies its
products worldwide. About 40% (Û14.1m.) of the production
is sold in Italy directly, where the market share for dolomite
is more than 70% and for dolomite mixes is nearly 90%. About
30% (Û10.6m.) is sold in other parts of Europe, while
Asia (€4.5m.) and the Americas (€4.9m.) account for
27% of Dolomite Franchi sales. A very minor portion
(Û0.4m.) is sold to Africa, mainly to Tunisia and
Morocco.
Refractory properties
Dolomite, a niche product with an excellent cost-benefit ratio,
is a unique product that has some good properties for chemical
and mechanical resistance in extreme applications, namely
refractories. It also shows a convenient elasticity modulus
showing to be an ideal and environmentaly
friendly substitute for magnesia-chrome products in
cement.
Dolomite has a fantastic ability to
attract and hold a clinker coating which protects the lining in
a burning zone environment. This also helps to reduce the kiln
shell temperature which reduces energy loss and input,
saving costs.
The material also has a very good
ability to resist alkali attack. Although it can suffer
adversely from the attack of sulphur and sulphates, it is
possible to modify the product bonding system to combat this
attack mechanism. In addition, the increasing use of secondary
or alternative fuels does not cause a problem for dolomite
burning zone refractories.
However, one of the main concerns
is that dolomite is hydrophobic. If not used properly, the
mineral can hydrate and will decay if not protected from its
reaction with moisture in the atmosphere.
Thanks to its properties and its
lower cost compared to usual refractories minerals such as
magnesia and bauxite in the present economic climate, research
and development divisions have recently been focusing on
developing new dolomite-based products for refractories
applications.
Mauricio Pinho, from Magnesita
Refratorios revealed to IM that the Brazilian
dolomite producer and refractories manufacturer has worked to
develop some new dolomite products with enhanced properties as
increased thermo-cycling resistance for the cement kilns and
corrosion resistance, specially for steel applications.
A boom in China?
The search for cheaper raw material or alternative to most
strategic refractories minerals such as bauxite or magnesia has
become a primary quest in the present climate. As a
consequence, the popularity of dolomite for refractories has
significantly increased during the last few years.
In many countries in the
world regardless of the status of their
industrialisation dolomite refractories used in the steel
industry has the most potential. Being a refractory material
for many applications in a mild steel operation from
electric arc to steel ladles it has become the key
refractory mineral for its application in the stainless steel
sector due to its best price/performance ratio.
“We definitely see more
potential for dolomite in our end-markets, not only because of
a certain undersaturation, but also because of an increased
technical acceptance in sectors, which so far were more dealing
with magnesia-based products. An example might be the
development of dolomite in high alloyed steel production with
sophisticated production routes,” Alessandro Romano
explained to IM.
Although the mineral does not have
all the refractory properties of magnesite, it is of interest
for the industry as a cheaper source of magnesia as dolomite
prices are up to 40% lower (see panel).
Romano believes that dolomite could
become an alternative in the refractories industry to strategic
minerals such as bauxite; particularly in steel ladles, which
are still lined with high-alumina bricks but not so much in
special ceramics.
An interesting development is the
adoption of doloma refractories to application areas, where
dolomite has not been used so far.
However, overcoming the rivalry
between moisture and dolomite would be a great progress in the
field of electric arc furnaces (EAF) with water cooled
panels.
The steel industry seems to offer
significant opportunities in the future as plants all over the
world are continuously checking possibilities to lower their
production costs. In this context a possible application of
dolomite products must be discussed as well. Depending on the
supply situation of other refractories made from alumina or
magnesia, new markets could emerge quite quickly such as
China.
“Sooner or later the Chinese
steel industry will detect dolomite as a refractory material
for ordinary steel ladles and then create a boom for dolomite
in China,” Romano said.
The impact on refractories would be
positive. High grade magnesia raw materials, whose availability
is becoming less, could be further used exclusively for
sophisticated applications in the consumer industries, whereas
the commodity part can be taken over by dolomite.
Challenges
Freight costs, which have recently significantly increased,
remain a concern particularly in east and south Europe.
However, they can be much cheaper to East Asia in countries
such as Malaysia, Taiwan or Thailand. “It is sometimes
just a few dollars more than if you go to the CIS [Commonwealth
of Independent States] countries,” a source from the
industry explained to IM.
According to Romano, one of the
biggest challenges is to bring back dolomite to its reputation
“as the best refractory material for a clean steel
production”.
Due to the high affinity of
dolomite to alumina and silica oxides, these main oxidic
inclusions form phases with the lime (CaO) component of the
dolomite and thus get captured in the brick or at its surface.
“The risk of getting oxidic inclusions in the steel is
less with dolomite than with other refractory materials.
Therefore dolomite refractories contribute to a clean steel
production,” he explained.
Outlook
After having been significantly affected by the financial
downturn, the dolomite industry seems to now be back on track,
following the trends of the steel industry. On the short term,
2010 has shown some improvement and next year should be a good
year for dolomite.
“As we can see from incoming
orders, the situation is further improving and I expect that
already in 2011 we will see a very good year for
dolomite,” Romano confirmed. However, the industry is not
yet ready to pop champagne as it seems still premature to say
if dolomite is really getting back to normal levels yet.
On the long-term the little push
could result from the present raw material supply situation
which could help dolomite emerge from the shadows.
Although it has remained until now
a humble mineral compared to the usual star refractory
minerals, dolomite could see its potential growing in the
future as a cheaper alternative to magnesia, mainly supplied by
China, which is trying to preserve resources and to feed its
growing domestic demand.
“Despite of the decreasing
specific refractory consumption in the steel industry, dolomite
is expected to grow further because of an increasing
substitution of other refractory materials by dolomite in steel
ladles,” Romano forecast.
Pinho from Magnesita confirmed that
the stainless steel market has shown some pick up and that
dolomite consumption has increased. “We expect that the
market will continue with this tendency, especially in Europe
and Scandinavia as we see some consistent recovery in the
production,” he said to IM. Magnesita has
therefore planned to increase its present dolomite production
of 500,000 tpa by 5-10% within the next few years (IM 22
November 2010: Magnesita to increase dolomite output by 5-10%
within 3 years)
Reduced prices compared to minerals
such as magnesia are obviously one of the key drivers to
develop new dolomite-based products.
A very interesting development is the adoption of doloma
refractories to application areas, where dolomite had never
been used. “I would not see a big potential in tundishes
but could imagine a remarkable share in production facilities
of primary metallurgy,” Romano underlined.
Dolomite at a glance
-
World production (2008): 103m. tonnes
for dimension stone, including limestone, dolomite and
related materials.
-
US production (2009): 1.83m. tonnes
(dimension stone)
-
Value: $377m. in 2009 up from $324m. in
2008 (dimension stone)
Properties
-
Sedimentary carbonate rock, also known as dolostone,
consisting mainly of the mineral dolomite
-
Formula: Calcium magnesium carbonate
(CaMg(CO3)2); differs from calcite
(CaCO3) in the addition of magnesium ions to
make the formula CaMg(CO3)2
-
Found all over the world; quite common in sedimentary
rock sequences; can be found in massive beds several
hundred feet thick
-
Deposits are usually associated with limestone
-
Limestone partially replaced by dolomite is referred to
as dolomitic limestone or as magnesian limestone
-
Good chemical and mechanical resistance for extreme
applications (refractories)
-
Good elasticity
Uses
-
Construction as a replacement for limestone
-
Refractories as source of MgO
-
Flux for the smelting of iron and steel where calcite
limestone is uncommon or too costly
-
Float glass production
- Horticulture: dolomite and dolomitic limestone are added
to soils and soilless potting mixes to lower their acidity
and as a magnesium source
Prices: a 40% cheaper alternative to magnesia?
According to industry sources, dolomite prices for
finished product used in refractories range at an average of
€350/tonne ($475/tonne) in Europe which is still 30-40%
lower than price levels for magnesia carbon finished products
such as bricks. It is around $550-650/tonne according to
another world leading dolomite producer, depending on size,
quantities and properties.
At present, dolomite is far less in
the focus of the consumers than magnesia products. It is not
considered a strategic mineral like bauxite and to a certain
extent also magnesite. Therefore demand driven price
fluctuations did not occur in the dolomite sector. The price
development for dolomite was rather determined by
comprehensible cost drivers like manpower, energy, binders and
others. “Compared with the complexity of dolomite
production, the dolomite prices are generally too low. And also
ours,” Alessandro Romano from RHI ’s Dolomite Franchi
told IM.
However, refractories manufacturers
show an increased interest in dolomite as it is more and more
seen as a cheaper alternative in terms of costs compared to
usual refractories minerals such as magnesia.
As far as alumina based products are concerned, these are
not any longer competing against dolomite in its typical
application area in steel ladles. “In many cases,
especially in the western countries, these products have
already been substituted by dolomite,” Romano
explained.
IM visited
Dolomite Franchi which strip mines 0.5m. tpa in Galarusso,
above Marone (by means of blasting) over the entire year. The
deposit has a mine life of 35 years.
The crude dolomite is then
transported in special lorries to the crushing and sifting
plant before being conveyed by cable cars at 500 metres high to
the production plant.
The crude material is then processed in six sintering
furnaces into a refractory material which is processed into
bricks or used for the production of mixes. As dolomite is
hydrophobic, final products are then packaged with nine layers
of hermetic aluminium and plastic sheets in order to resist
humidity and avoid damage during transportation.
“Sooner or later the
Chinese steel industry will detect dolomite as refractory
material”
Alessandro Romano, head of Franchi
Dolomite’s plant, talked to IM about the
potential of dolomite for refractories
How is the market
performing for dolomite?
Alessandro Romano:
As far as demand is concerned, it shows a parallel curve to
standard magnesia-based refractories. Since the major part of
dolomite goes into the steel industry, the ups and downs of the
steel sector are reflected in the development of dolomite as
well.
What factors have most
impacted the industry lately?
AR: It was for
sure the economic crisis in 2008 and 2009, which led to a
necessary downsizing of the installed capacities. Meanwhile,
some of the strict measures could be released again. However,
the industry is not yet back to business as usual.
What has changed in the
industry?
AR: Similarly to
many other branches, the dolomite industry has strongly
concentrated on environmental issues. Whether it was new
ecologic binders for shaped dolomite refractories or modernised
plant equipment in order to minimise gas, dust and noise
emissions, all these measures made dolomite refractories a very
advanced, state-of-the-art product for the steel industry.
Where do you see emerging
markets for dolomite?
AR: I think that
steel plants all over the world are continuously checking
possibilities to lower their production costs. In this context,
a possible application of dolomite products must be discussed
as well. Depending on the supply situation of other
refractories made from alumina minerals or magnesia, new
markets could emerge quite quickly.
Sooner or later, the Chinese steel
industry will detect dolomite as refractory material for
ordinary steel ladles and then create a boom for dolomite in
China.
What are the new R&D
trends for dolomite?
AR: A very
interesting development is the adoption of doloma refractories
to application areas, where dolomite has not been used so far.
I would not see a big potential in tundishes, but could imagine
a remarkable share in production facilities of primary
metallurgy.
Particularily I think about a
revitalisation of its use in the big integrated BOF [basic
oxygen furnaces] steel shops. But also overcoming the rivalry
between moisture and dolomite would be a great progress in the
field of electric arc furnaces (EAF) with water cooled
panels.
What is your
forecast?
AR: I expect the
dolomite industry to grow further despite of the decreasing
specific refractory consumption in the steel industry, because
of an increasing substitution of other refractory materials by
dolomite in steel ladles.
As we can see from incoming orders, the situation is further
improving and I expect that already in 2011 we will see a very
good year for dolomite. Whether it will be already a year back
to normal or just a single flash will become apparent in the
future.