Zircon (zirconium silicate - ZrSiO4) is an important source
of zirconia (zirconium oxide - ZrO2) and zirconium
(Zr).
Due to its density of 4.68, economic quantities of zircon
are primarily contained within heavy mineral sands (HMS), a
type of sedimentary deposit. Additional small quantities are
also currently derived from baddeleyite mining in Kovdor,
Russia. Zirconium and zirconia may be derived from various
other minerals, with a notable example being eudialyte
contained within Alkane Resources’ Australian
Dubbo Project.
Zircon finds uses in various applications such as ceramics,
and in the foundry industry, mostly in the form of flour and
sand for casting and refractory purposes. Zirconia as fused
zirconia finds use in refractories, abrasives and ceramic
pigments, while zirconium chemicals finds use in gemstones,
technical ceramics, cosmetics, coatings and more. Zircon is
also used as zirconium metal, which finds use in nuclear
applications, space and aeronautic industries, as well as in
biomedicine.
According to the US Geological Survey (USGS), 2016 world
production of zirconium mineral concentrates amounted to 1.46m
tonnes. In that same year, Iluka Resources produced 347,000
tonnes of zircon.
Iluka Resources, the world’s largest producer
of zircon, estimates around 50% of its demand resides in
ceramics, around 30% in refractory and foundry applications,
and 20% of demand is from zirconia, zirconium chemicals and
metal in 2017.
These demand figures are broadly in line with global
estimates contained within The Zircon Industry
Association’s (ZIA) Technical Handbook on
Zirconium and Zirconium Compounds, published in 2015.
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Iluka Resource’s
Jacinth-Ambrosia deposit is capable of producing up
to
300,000 tpa zircon, with production levels
typically related to market demand
conditions. Indeed, Iluka announced in February 2016
that mining and
concentrating operations are to be suspended from 16
April "for a period
of 18-24 months".
Source: Iluka
Resources
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The ZIA states that the most important market for zircon and
zirconia is the ceramics industry, where it is used in the
production of "ceramic bodies, glazes, enamels, frits and
pigments applied to traditional ceramics, which includes wall
and floor ceramic tiles, porcelain tiles, sanitaryware,
washbasins, tableware, special porcelains and industrial tiles,
among others".
Zircon is commonly thought of as an opacifier in traditional
ceramics, while zirconia has an important role in the
production of ceramic pigments used in ceramic tiles, tableware
and sanitary ware, among other products.
Historically, the growth of consumption in ceramics has been
largely driven by tile demand. Growth in tile production can be
linked to construction activity, with the highest rates of
construction presently in Asia, especially China. The Chinese
construction sector is the largest and one of the most rapidly
growing in the world, despite several years of slow
development.
As part of a business briefing session in 2015, Simon Hay,
then general manager at Iluka, expanding on how the ceramics
industry is changing in its consumption of zircon, stated that
"over those past few years we’ve observed less
zircon being used in the ceramic body and more zircon being
used in frits, glazes and ceramic colour pigments, again
associated mostly with digital printing changes."
| Floor space of building under construction
and completed in China |
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Historically, the growth of consumption in
ceramics has been largely driven by tile demand.
Growth in tile production can be linked to
construction activity, with the highest rates of
construction presently in Asia, especially China. The
graph shows that while construction
in China appears to be rising, the amount of
buildings completed has remained relatively
stable.
Source: China
Statistical Yearbook,
2016
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The rise of tile digital printing has, according to Iluka,
led to an increase in the popularity of glazed porcelain and
glazed rustic tiles. This industry trend has resulted in "a
year-on-year increase in zircon loadings", Hay said at the
time.
Zircon may find further application in traditional ceramics
as a partial replacement for zinc oxide in sanitaryware,
according to a paper by Boudeghdegh et al. (2015) who also
concluded that 14.5 wt% of zircon and 2.5 wt% of ZnO, shows
better physical-mechanical properties and aesthetic whiteness
when compared with the reference sample containing 7-9 wt%
zircon.
Aside from traditional ceramics, zirconia can be turned into
an advanced ceramic by either 'stabilising’ it or
by mixing it with other compounds such as alumina zirconia. The
resultant materials can have a high strength, high fracture
toughness, high density and more, suiting it to a range of
specialised applications.
Zirconia can therefore find applications not only in casting
and moulding but in grinding media, piezoelectrics,
nanotechnology, optical materials, memory devices, fuel cells,
catalysts as well as biosensing and biomedical
applications.
The number of new uses for zirconia will continue to
increase thanks to its relative abundance in nature and mining,
as well as its innate characteristics. While low-grade
stabilised zirconia has been widely used in refractories,
pigment coatings and pottery colours for a number of decades,
it has only been during the past 40 years that technical-grade
zirconias have been produced for more advanced
applications.
A recent example is one from Zircoa GmbH, which in September
released its long-awaited Black Diamond product, used for
tooling, milling media, mud pump liners, wire drawings or
similar applications. A shift in the company’s
philosophy in 2014 meant that R&D became proactive rather
than reactive, resulting in a product that has a good fracture
toughness, is hard and dense, and compares favorably in most
aspects to the widely used material, Yttria Stabilized
Zirconia.
In his 2016 review on Solid Oxide Fuel Cells (SOFC) for the
21st Century, Kevin Kendall, Professor of Chemical Engineering,
University of Birmingham, makes a bold prediction for the
future of zircon demand. His quote is representative of the
potential demand to arise out of the swathe of research
currently going on across the world of zircon, zirconia and
zirconium: "there is little doubt that large quantities of
zirconia will be needed for the SOFC application in the years
to come, with annual production rising to more than 1m tonnes
(equivalent) a year in 2100, rather as titania expanded in the
last century for pigment applications".
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ZIA confident on zircon supply demand
trajectory
With questions on zircon’s
supply-demand trajectory, given the bold predictions by
the SOFC survey, Siobhan
Lismore-Scott, IM Consultant
Editor, speaks to Keven Harlow, executive
director of the Zircon Industry Association, about the
body’s expectations for the future
Have you/the association noted a shift in
demand?
We have seen that, overall, the underlying demand for
zircon is growing moderately; however, with some
regional differences: for example, after several
years of depressed consumption, Europe is improving
and the US is ready to recover, albeit timidly. India
is the bright spot in the zircon world, while China
remains flat due to plant closures following
environmental inspections that the government is
implementing strictly.
New sources of supply or different grades
needed?
ZIA believes that the market is in balance, but
current mines will progressively face grade and
production decreases over the next few years, so new
mining projects will always be necessary to avert a
shortfall as any remaining inventory is gradually
consumed.
Has the downturn in steel markets affected
the industry at all?
Zircon usage in the steel industry is much smaller
than for ceramics in total zircon consumption. That
said, zircon demand in foundry and refractory
applications has been negatively affected by the
downturn in steel markets. On a qualitative side, we
have seen that higher quality refractories, which
demand more zircon, are increasingly used to lengthen
the refractory life-time – an example of the
properties of zircon adding real value.
Where is growth expected (in terms of
location) and why?
The ZIA is constantly monitoring both R&D and the
industry, looking for opportunities that might
promote additional consumption of zircon. New
applications are being discovered all the time, but
ceramics will remain the main driver of global zircon
consumption. As more developing countries grow, their
middle class and infrastructure also develop, leading
to increased demand for ceramics. India currently
shows a high growth? level, and more nations in the
Middle East, Africa, and South East Asia are expected
to contribute positively, either through their own
local industry, or by importing ceramic products from
the existing exporting countries.
Are there concerns over substitution at
all?
Substitution is always a concern, but the ZIA
promotes zircon as having many attributes beyond
price, and as a product that delivers substantial
added value. Substitution occurred in the past
when price increased excessively; however, we are now
in a relatively low-price environment and producers
seem to show restraint. There will always be
adjustment of formulations depending on material
prices, but zircon has several unique properties
(opacity and whiteness, hardness, low thermal
expansion, high melting point, thermal conductivity,
chemically inert, low neutron absorption) that are
able to be valued through the life cycle.
Or about new sources of supply flooding the
market?
ZIA believes that currently the market is balanced
with sufficient inventory to meet any jump in demand.
Remember that there is a long lead time for new
projects to come on stream, so it is very unlikely
that the market will be flooded. We are also in an
economic environment that’s different
from the previous peaks and troughs of the zircon
cycle. If new entrants do enter the market, this will
temper any downstream user concerns of a possible
shortage of raw materials. And new production will be
required to replace mines that will gradually be
depleted.
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