A growing global population is boosting demand for materials
for building and technology, sectors in which mineral sands
play a key role - predominantly through ceramics for zirconium
minerals and pigments for titanium minerals.
Emerging countries - where economic growth tends to outpace
global gross domestic product (GDP) - present the biggest
opportunity for growth in titanium and zirconium demand.
And given very low recycling rates - zero, in the case of
TiO2 pigment - long-term demand for companies looking to
produce mineral sands looks very healthy.
But the depletion of easy-to-access resources to meet that
demand raises questions about where and when the next Eneabba,
Jacinth Ambrosia or Richards Bay might be found.
The finite nature of mineral resources has influenced the
titanium pigment industry’s development. For
example, while the preferred feedstock of chloride pigment
producers is natural rutile, they have in the past made various
upgraded products such as titania slag and synthetic rutile
from ilmenite when rutile sources were scare.
The perceived shortage in some mineral sand minerals,
particularly rutile, has driven innovation in pigment
processing technology, particularly in chloride pigment. This
innovation is likely to continue for as long as rutile supply
One element of this innovation is the blending of
feedstocks. Some producers can use a combination of feedstocks
(with variable TiO2 and other elements) in their processes;
others are able to use a lower-grade titanium feedstock. Only
Chemours uses ilmenite with TiO2 content of more than 55% TiO2
in its chloride process.
Currently, natural rutile, synthetic rutile, upgraded and
coarse slag (>85% TiO2) are suitable for chloride-route
pigment production, which is more environmentally friendly and
produces much less waste.
A balance must be achieved between a perceived shortage in
high-grade titanium feedstocks and the need to preserve the
environment. This is evident in China, where chloride pigment
production is growing, albeit very slowly.
The growth rate of chloride and sulfate pigment production
was a hot topic at the Australian Informa 2018 Mineral Sands
conference earlier this year in Perth, Western Australia, for
Doubts were cast as long ago as 2009 about the pace at which
this change would take place, particularly in China. Since
then, though, China has managed to build a combined 250,000
tonnes per year of chloride pigment capacity between Lomon
Billions, Citic Titanium Industry, Yunnan Xinli Non-Ferrous
Metals (although operations there are reported to be
suspended), Luohe Xingmao Titanium (likewise), and Pangang
Group, which has a trial production line in operation.
Capacity for chloride pigment elsewhere is set to rise,
particularly if the much-anticipated Tronox-Cristal merger
takes place. Cristal built its Saudi Arabian Yanbu chloride
pigment production facility in 1989 only for it to have
continually suffered from low operating rates ever since.
Similarly, the company has not yet reached the production
stage with its Jazan titanium slagger, despite millions of
dollars of investment since 2015 in the hope of producing
If Tronox is able to bring the Yanbu works to full operating
capacity, and bring Jazan online with its in-house expertise
following the merger, it will require ilmenite as a feedstock
for Jazan and perhaps even rutile to help feed Yanbu.
Tronox operates the Cooljarloo mine in Australia, as well as
the Namakwa and KZN mines in South Africa. Presumably,
production at these mines will be enough to feed the Cristal
smelter and pigment operations, although these mines will
ultimately run down and new mines will have to be found to
Despite some setbacks, then, it seems that overall chloride
route production is favored, particularly thanks to its
environmental sustainability. But what can current and future
producers do about resource scarcity?
The answer is: not much in the short term. While Chemours
has the greatest flexibility in terms of switching feedstocks,
not all pigment producers have the same ability.
Factors such as impurities, size distribution, density and
even the shape of slag, rutile, synthetic rutile and ilmenite
make it hard for producers to switch from rutile to a chloride
ilmenite, for example, or even from a sulfate ilmenite to a
sulfate slag, since these can affect the performance of the
The choice of feedstock depends on factors such as the
process plant design; the economics of the process due to
differences in price of feedstocks and various impurities; any
loss in production due to process and equipment downtime in
testing a new feedstock; the cost of waste treatment and solid
waste disposal; and quality of the TiO2 pigment product.
Switching feedstocks has physical, chemical and economic
implications for users.
Many market participants have tipped Kronos, a major global
pigment producer, to be affected most by the dwindling
availability of high-grade titanium feedstock. Because its
Belgian plant requires a predominantly rutile feedstock, it
will be forced to pay a higher price to its suppliers, one
market source said.
One short-term solution will come from Iluka Resources,
which is planning to bring online in the first half of 2019
around about 200,000 tpy of synthetic rutile production, fed by
around 370,000 tpy of chloride ilmenite from Cataby at its SR2
While this will provide some relief, it will not help all
pigment producers and cannot help some other parts of the
sector such as welding.
|Iluka is looking to complete a DFS into the
of Jacinth Ambrosia, which would result in a ~30%
increase in ore throughput to offset declining ore
In the long term
There are several possible long-term solutions for the
perceived shortage of high grade titanium feedstocks.
For example, global chloride feedstock capacity could
increase via the discovery and development of some large
high-quality rutile or ilmenite deposits, as well as the
possibility of adding some new slag or synthetic rutile
For ilmenite, this means deposits that can either be used
directly in pigment production or that can be upgraded. For
ilmenite used directly in pigment production, the chemistry for
sulfate or chloride route production should be considered;
sulfate-suitable ilmenite tends to more primary in nature and
has more FeO and fewer Fe2O3 phases in the iron content, making
it more soluble in sulfuric acid for the sulfate pigment
Chloride grade ilmenite, though, is more tertiary in nature
so it contains more Fe2O3 and minimal FeO, which makes it
easier to chlorinate in a chloride route plant.
Where ilmenite undergoes upgrading via slag production, a
specific type of ilmenite is also required. This is because,
just as in direct use, there are elements such as chrome that
carry across and make the slag unsuitable for pigment
production. Chrome, for example, will typically affect sulfate
and chloride slag production methods.
During the slagging process, the slag bullets or pigs that
are produced are smelted, crushed and screened. The resulting
coarse particles are chloride grade while the fine particles
are sulfate grade. While there tends to be some quality
segregation between the particle sizes, they are usually close
for titanium content and other elements; both grades are
normally made at the same time, from the same ilmenite
(regardless of whether that be a sulfate or chloride grade
In fact, sulfate ilmenite is considered the best feedstock
for slag production and chloride grade ilmenite for Becher
process synthetic rutile production, which is again due to the
FeO/Fe2O3 ratio. High FeO is best for pig iron formation - it
can be tapped off separately in the slag furnace to leave the
titanium slag. FeO does not reduce with coal in a synthetic
rutile kiln, however, whereas the Fe2O3 reacting with CO from
the coal to leave metallic iron on the ilmenite grains and CO2
is relatively rapid in comparison.
So although not every ilmenite is suitable, it is the most
widespread titanium mineral on earth, which gives explorers a
very good chance of finding something useable.
The vast majority of the world’s ilmenite
resources are found in Australia, South Africa, India, Brazil,
Madagascar and the United States, in mineral sand deposits but
also in primary hard rock deposits such as Tellnes in Norway
and Allard Lake in Quebec, Canada.
In 2017, the United States Geological Survey (USGS)
estimated world ilmenite reserves at 870 million tonnes, with
production amounting to 6.2 million tonnes in that same year.
This includes the ilmenite produced in Canada and South Africa,
which is primarily used in the production of slag.
An alternative to finding and using ilmenite and, in some
cases, to upgrading it is to find naturally occurring rutile,
which unlike rutile does not need to be upgraded. But in
contrast to ilmenite, world reserves of rutile are concentrated
in Australia, Kenya and South Africa. In 2017, the USGS
estimated global rutile production at 900,000 tonnes from a
global reserve of 62 million tonnes.
Other titanium feedstock-using industries, such as welding,
add another layer of complication. The welding industry cannot
use synthetic rutile but only natural rutile (TiO2 of 94%
purity and better is preferred) or the higher grades of
leucoxene (88% and over), slag and sometimes reduced
It is not only the chloride pigment industry that requires
more rutile. But what if none is forthcoming?
There are multiple ways in which plentiful supply of
ilmenite can be upgraded into chloride pigment production as
well as sulfate pigment production, even if the volume of
suitable ilmenite is unknown.
And there is a very good case for human ingenuity,
particularly for the welding industry, in that it will find
ways to work with the deposits that are available.
Rio Tinto produces titanium slag at Sorel in Canada as well
as at Richards Bay Minerals in South Africa. TiZir produces
titanium slag at Tyssedal in Norway and Lomon Billions at its
Chinese operations. Richards Bay, Sorel and TiZir produce slag
suitable for both the chloride- and sulfate-processing
Tronox produces titanium slag at its operations in South
Africa using its own proprietary technology. It is suitable for
both chloride and sulfate processing.
Synthetic rutile producers
Iluka and Tronox produce most of the world’s
synthetic rutile at their plants in Western Australia (Tronox
is also a large consumer of synthetic rutile in its pigment
production process). Other plants in India and Malaysia use a
different processing technique.
Maoming Ubridge Group is reported to be working on a
synthetic rutile operation in China. It has 100% of Strandline
Resources’ future ilmenite production under
offtake agreement, presumably as feedstock for this