Soaring prices for zircon are causing end users
to evaluate cheaper substitutes for a range of
applications, including foundries (pictured) where
chromite sand can replace its costlier counterpart
The world market for zircon and downstream zirconium materials
represents a $3.5bn industry, which has witnessed dramatic
changes in demand and supply during the past few years. The
future forecast shortage in zircon supply has been brought
forward due to strong demand in China, and has caught many
people by surprise as they adjust to the reality of the current
situation. Across all applications worldwide, the issue now is
how to allocate approximately 1.3m. tpa of zircon when demand
exceeds supply by more than 100,000 tpa in 2011.
Though the immediate concern is
zircon supply in 2011, supply in future years is even more
uncertain. TZ Minerals International Pty Ltd (TZMI) is
forecasting that zircon supply will stay at current levels for
the next several years (Figure 1).
Figure 1: Zircon supply outlook to 2020
Source: TZ Minerals International
New zircon production capacity will only offset falling
production from existing mining operations. To make matters
worse, the poor financial returns of recent years have deterred
any new investment in mineral sands operations. Higher
production costs and unfavourable currency exchange rates have
only added to the problem. It has only been the result of sharp
increases in zircon prices that investment in new mining
capacity is starting to look attractive in terms of domestic
currencies such as the Australian dollar or South African
Yet even for new mining projects
which have completed feasibility studies and have financing in
place, output from these mines are not expected to contribute
to zircon supply for another two or three years. Complicating
the supply situation, these new mineral sands projects contain
moderate to very low ratios of zircon to titania minerals, thus
reducing their contribution to future zircon supply.
Beyond this, it typically takes
7-10 years from the time a new mineral sands deposit is
discovered to it achieving full commercial production. In this
category, new Eucla Basin type developments (South Australia)
have been announced. But, by the time these mines are fully
operational, output from existing mines will have declined and
no net gain in world zircon supply will be achieved. This is
why total world zircon supply is not likely to increase
significantly from current levels for many years. So, zircon
end users will continue in their struggle to secure adequate
supply in the years to come.
The present response of mineral
sands companies to the shortage has been to allocate zircon to
customers based on their consumption in 2010 rather than
forecast demand for 2011. This is an important distinction as
forecast demand for 2011 is very different for mature markets
in Europe and North America, compared to high growth economies
in Asia and South America.
Various sources have estimated
Chinas zircon consumption was between 600,000 and 650,000
tonnes in 2010. With a zircon growth rate close to 20%, and
China consuming about 50% of world output, Chinas 2011
demand for zircon will increase by 120,000 to 130,000
Chinas high growth rate is
not a sudden phenomenon, as annual growth rates have been
approximately twice the rate of growth in GDP for the past 20
years. The end uses in China with the highest growth have been
ceramics, and this rate of growth has now slowed during the
past two years. Growth has continued for zirconium chemicals
and fused zirconia, as well as for glass and steelmaking
refractories. This is directly related to the urbanisation of
China, wherein all construction materials have experienced
In addition, a significant
percentage of zircon consumed in 2010 was supplied from stocks
built up by mineral sands companies during the global financial
crisis, or due to the drawdown of stocks by end users. Zircon
supply is now coming from existing production, so supply in
2011 will be less than last year.
The relationship between mineral
sands companies and end users has also become an important
supply factor. The loyal, long term zircon customers recognise
that, while prices are important, supply is more critical to
maintaining operations. Consistent zircon quality is also
important, and is also likely to come under pressure as miners
seek to maximise output. Zircon specifications requiring low
impurities, such as alumina, iron, or titania, may reduce
zircon production yields by 10% or more.
The difference between premium and
other grades of zircon sand is also an important distinction.
Under prevailing conditions, true premium grade zircon will
become very scarce like gold, but leading companies
will find ways to utilise sub grades without compromising end
product specifications and performance.
Traditionally, Australia and South
Africa have supplied approximately 75% of zircon and titania
minerals worldwide, but there is increasing recognition of the
strategic significance of these minerals and the value adding
opportunities. South Africas National Empowerment Fund
has just announced plans to invest $2.2bn to set up a
vertically integrated rare metals facility to transform
minerals sands such as zircon and titania minerals into value
added chemicals, pigments and metals to add value to natural
resources and to create much needed employment.
Zircon, for example, can be
processed into zirconium chemicals and powders, or all the way
to zirconium metal for nuclear and industrial applications.
China has done this for many years, with its rare earths
industry being a prime example.
End users of zircon and zirconium
materials are now seeking to substitute alternative materials,
but are finding there are few options which provide equivalent
or similar performance. In general, zircon (Zr) is
irreplaceable due to its specific and unique chemical and
physical properties in almost all applications. It is also
likely that wider industrial applications of Zr are yet to be
discovered and understood in years to come. Any assessment of
the potential to substitute for zircon requires an analysis of
the main end uses for zircon, and the main attributes needed
for each application.
TZMI has compared the main end uses
for zircon between 2000 and 2008, plus a forecast for 2012 as
shown in Figure 2. Ceramics remains the largest end use at 56 %
for zircon, followed by zirconia and zirconium chemicals which
have doubled from 9% in 1990 to a forecast 18% in 2012, which
would require about 250,000 tonnes of zircon.
There is often confusion in
understanding which zirconium materials are being discussed due
to the different names which are used across the industry to
describe each of the main zirconium intermediates or end
products. Table 1 describes the main forms of zirconium
materials and alternative sources of zirconium.
At present, naturally occurring
zirconia, or baddeleyite, is the only commercially available
source of zirconium apart from zircon. However, total
baddeleyite production is only 7,000-8,000 tpa and is a
by-product of iron ore from Kovdor Mining on the Kola Peninsula
Other sources of zirconium are
found in complex polymetallic ore bodies, with major deposits
discovered in Australia and Canada. The most advanced project
of this type is the Dubbo zirconia project held by Alkane
Resources Ltd, which is expected to produce 6,000-15,000 tpa of
zirconium chemicals and powders, niobium, as well as light and
heavy rare earths (see panel). This is a strategically
significant project because the zirconium chemicals and powders
are independent of both the zircon supply chain, and
Chinas zirconium chemicals industry, which supplies over
90% of world supply. Similarly, it provides a strategic
alternative to China for rare earths.
Finding and defining an economic
polymetallic resource with access to good infrastructure and
services is the first step, but separating and recovering the
valuable metals is the real challenge. This is because it is
difficult to put the metals in solution without dissolving the
host rock as well.
Alkanes Dubbo project is one
example where the separation into zirconium, niobium, plus
light and heavy are earth streams has been successfully
achieved by using a sulphuric acid roast and subsequent leach.
The Dubbo ore body is also large and consistent throughout,
which simplifies processing to ensure stable quality products
to be produced.
Figure 2: Zircon usage by application
Source: TZ Minerals International
Analysis of the major end uses for zircon shows that there is
no readily available substitute for zircon in over 80% of
applications. Table 2 shows the potential to substitute zircon
in the top four applications for zircon which account for 96%
of total consumption.
Where substitution is possible,
this is mainly due to the use of other zirconium-derived raw
materials, such as naturally occurring zirconium dioxide,
baddeleyite, or zirconium from complex polymetallic ores.
Substitution in this discussion refers to alternatives to
Table 2: Potential to substitute for zircon in major
|Zirconia & chemicals
*2012 zircon market: 1.4m. tpa. No zircon substitutes
for over 80% of demand.
Sources: TZ Minerals International & TCMS
Table 3: Zircon substitutes in ceramics
||World production m. tpa
|Tin oxide SnO2
Sources: Ceramic Glazes-Parmelee,
LME, and USGS
The main use for zircon is in ceramics as an opacifier in floor
tiles, sanitaryware, and tableware. Gres porcellanto tiles also
consume significant quantities of zircon. In total, ceramics
applications are responsible for over 50% of total zircon
consumed. Finely milled or micronised zircon imparts a high
degree of whiteness due to its high refractive index. Zircon
also has a low solubility in silicate melts, and is
commercially available in large volumes. Zircon has substituted
for tin oxide in ceramics since the 1950s due to the favourable
combination of properties, cheap price, and ready
Some European opacifier producers
threatened to stop using zircon as an opacifier as prices moved
higher over the past two decades, but a rational analysis of
the alternatives shows that this was a myth, driven by
commercial considerations to maintain low prices. Table 3 lists
the key properties for ceramic opacifiers and potential
alternatives. Tin oxide is recognised as a superior opacifier
to zircon, but world production is very limited and its price
is nearly ten times that of zircon. Alumina is often quoted as
an alternative to zircon due to its lower price, but has a
lower refractive index and produces a matt glaze.
Thrifting of zircon has resulted in
specific consumption halving during the past 20 years to the
present level of about 80g/m2, so further gains
appear to be limited. Sensitivity to the zircon price for
ceramic tiles also remains low, with the cost of zircon
opacifier being approximately $0.16/m2 compared to
ceramic tile production costs of around $6/m2 in
China. Even with higher zircon prices in 2011, the cost of
zircon opacifier is less than 3% of the cost of a ceramic tile,
so end users can continue to absorb price increases.
White tiles are the standard of the
industry (like white is the standard colour for motor cars) and
they may simply cost a little more. It is also worthwhile to
consider the relationship between titanium dioxide pigment
prices and opacifier prices; historically the latter has always
followed the former.
Zircon is also used in the
production of coloured zircon pigments, where approximately
40,000 tpa of zircon is converted into either fused zirconia or
chemical zirconia to produce praseodymium yellows, vanadium
blues, or iron reds. South African baddeleyite from Palabora
was used extensively for zircon pigments until 2001 when the
open cut mine went underground and production of baddeleyite as
a by-product effectively ceased.
Russian baddeleyite has only met
with limited success in zircon colours. Substitution of zircon
from polymetallic sources is likely for zircon pigments where
zirconium chemicals and powders are used, while their use in
ceramic opacifiers is also a longer term opportunity.
Zirconium materials represent the next largest market for
zircon, with TZMI forecasting this segment to consume 18% of
total zircon by 2012, which has doubled during the past decade.
Figure 3 shows the diverse end uses for zirconium, which are
used in everyday items.
In most applications, the use of
zirconium materials provides superior properties and
performance in each application, with no alternative material
to take its place. For most applications, the cost of the
zirconium material is a very minor part of the total production
cost as only a small percentage is used, or parts are very
small. As highlighted in Table 1, the two alternatives to
zircon for a source of zirconium are baddeleyite and complex
Most high purity zirconium
chemicals and powders are based on the use of zirconium
oxychloride (ZrOCl2.8H2O), commonly
referred to as ZOC. With China producing over 90%
of world output, the dearth of zircon has resulted in shortages
of ZOC, as well as zirconium chemicals and chemical zirconia.
This has resulted in downstream zirconium products increasing
in price by more than twice the zircon increase.
Chinese ZOC prices have doubled
from $1,400/tonne in mid-2010 to about $2,800/tonne, FOB China
by the end of March 2011. During the same time, zircon prices
have increased from around $900/tonne to $1,600-2,000/tonne,
CIF China as end users scramble to purchase zircon from trading
companies on the spot market.
Using $1,800/tonne as a reference
price, there has been a $900/tonne increase in the price of
zircon. As approximately 0.65 tonnes of zircon is needed to
produce 1 tonne of ZOC (36% ZrO2), the additional
ZOC price due to zircon is approximately $585/tonne. The
additional profit of $815/tonne reflects the shortage of
zircon, as well as increased chemical and environmental
The shortage of ZOC has also caused
a reduction in the production of chemical zirconia powders in
China, with prices increasing higher than the ZOC price
increases. Chemical zirconia prices are now
$10,000-14,000/tonne, FOB China. Reduced exports of ZOC are
also having a significant impact on all zirconium chemicals
users worldwide, where supply issues have become critical for
many end users.
Figure 3: Applications for zirconium materials
Source: Alkane Resources
Zircon was one of the key refractories raw materials used in
steelmaking until the end of the 1980s when it was replaced by
superior alumina-spinel compositions. Today, zircon
refractories have been mostly replaced by fused zirconia
refractory materials produced from zircon, which are used
extensively for glassmaking and steelmaking refractories.
In glassmaking refractories,
monoclinic fused zirconia is added with zircon to form
alumina-zirconia-silica (AZS) refractories used to line glass
tanks for flat glass manufacture. Most liquid crystal display
(LCD) and plasma display panels (PDP) use high zirconia
refractory blocks in the furnace linings where minimal
impurities are desirable (see IM April 2011: Fused-cast for
Steelmaking refractories also use
monoclinic fused zirconia as the main raw material for
producing stabilised zirconia refractory materials. Zirconia is
stabilised by either calcia, magnesia, or yttria.
One of the main uses for stabilised
zirconia is for flow control nozzles used in slide gates.
Some of the key performance
requirements for zirconia refractories are shown in Table 4. It
is estimated that approximately 100,000 tpa of zircon is used
to produce fused zirconia products. Fused zirconia has
traditionally been used in refractories due to its low cost
compared to chemical zirconia materials. However, it is
expected that increased zircon prices will allow zirconia
derived from polymetallic ores to be competitive as an
alternative to fused zirconia when new sources of production
The use of zircon in foundries, sand casting and investment
casting applications is one of the oldest uses for zircon since
it was first used in the 1930s. Zircon is unique in these
applications as it is not consumed in the process. This allows
zircon to be recycled to remove binders and separate other
Zircon possesses many favourable
properties which make it the first material of choice for
foundry applications, and a list of the main attributes are
shown in Table 5. Approximately 150,000 tpa of zircon is
consumed in foundry and metal casting applications, which has
remained relatively constant during the past twenty years,
despite large fluctuations in supply and availability.
The main competitor to zircon is
chromite, which has enjoyed a rapid growth in demand for
foundry applications, and chromite consumption is estimated to
be about 700,000 tpa. It is also estimated that chromite could
substitute for zircon in up to 50% of foundry applications, and
with zircon now costing four to five times more than chromite,
there will be increased efforts to replace zircon.
The zircon shortage will force end users to critically review
the need for its usage in each of the major applications.
However, in most cases, there are no obvious alternatives to
zircon. Therefore, substitution is largely a myth, while the
zircon supply chain is virtually empty with no recovery in
sight for the near to medium term.
Sensitivity to substitution is
generally low, with other minerals or polymetallic ore bodies
needed as a source of zirconium. The trend of increasing zircon
prices is set to continue, with no significant zircon supply
coming on stream for the immediate future. Supply of zircon and
downstream products has become a significant strategic issue
for many companies, with prices for downstream zirconium
chemicals and powders increasing by much more than the zircon
price alone. No immediate relief is in sight, however
polymetallic ores offer a significant new source of material
for the high growth rate zirconium chemicals and chemical
zirconia segment from late 2013 onwards.
Contributor: Alister MacDonald is the director of
Technical Ceramic Marketing Services Pty Ltd, with over 25
years experience in zircon and zirconium materials. This
article is adapted from the paper, The myth of zircon
substitution, presented at the TZMI Asia in Focus
Congress in Hong Kong, November 2010.
Table 1: Zirconium nomenclature and alternatives
Zircon (ZrSiO4): zirconium silicate mineral
from which most zirconia, and zirconium materials are
Zirconia (ZrO2): zirconium dioxide exists in three
Monoclinic, tetragonal, and cubic;
Stabilised by rare earths such as yttria or ceria.
Alternative zirconium sources include natural zirconia,
baddeleyite, or complex ores, but current supply is limited or
is under development:
- Russian baddeleyite: ~7-8,000 tpa;
- Alkanes Dubbo Zirconia Project: 6-15,000k tpa.
(Zr): produced from zircon or zirconium
Zirconium materials: including
chemicals, oxides, and metals.
Spotlight: Dubbo zirconia project
The Dubbo zirconia project (DZP) in New South Wales, Australia,
is one of the worlds most advanced developments for
zirconium, niobium, yttrium and rare earth production and is
based upon a world class resource. This large resource has over
100 years open minable life at a 1m. tpa production rate.
Mineral concentrations at the Toongi
A demonstration pilot plant (DPP) at ANSTO (Australian Nuclear
Science and Technology Organisation) has been operating
continuously since 2008 and has proven the flow sheet for the
DZP. Apart from zirconium, the DZP offers a new source for
heavy rare earths, particularly yttrium, gadolinium, dysprosium
Production output from the Dubbo zirconia
||400,000 tpa (Base Case)
|ZBS, ZOH, ZBC, ZrO2
||15,000 tpa (6,000 tpa ZrO2)
||37,000 tpa (15,000 tpa ZrO2)
|Nb -Ta concentrate
|| 2,000 tpa (1,400 tpa Nb2O5)
||5,000 tpa (3,500 tpa Nb2O5)
||1,980 tpa (REOs)
||4,950 tpa (REOs)
||600 tpa (REOs)
||1,500 tpa (REOs)
*ZBS = zirconium basic sulphate; ZOH = zirconium hydroxide; ZBC
= zirconium carbonate; ZrO2 = zirconia ; equivalent
~99% ZrO2 + HfO2 basis. Nb-Ta concentrate
= ~70% Nb2O5; 1.0%
Ta2O5 calcined basis.
LREE = lanthanum, cerium, neodymium and praseodymium. YHREE =
yttrium, gadolinium, dysprosium and terbium. (70% rec)
A detailed feasibility study is to be completed in mid-2011,
with construction expected to commence in early 2012. First
production is expected late in 2013, with potential to expand
beyond 1m. tpa annual production due to the large ore body
which is open at depth.
Source: Alkane Resources