Having announced plans to extract rare earths out of
everything from Siberian mountains to moon rocks,
Russia’s latest announcement that it plans to
exploit yet another obscure source material for the lanthanide
minerals is unlikely to set many tongues wagging in
anticipation.
But the tirelessness with which both Russian private and
state institutions fund and promote research into new ways of
producing rare earths provides an engagingly abstract backdrop
to rather miserable efforts elsewhere in the world to make a
profit from simply mining the minerals from commonly-occurring
ores like monazite and bastnaesite.
In the latest Russian project to come to the fore, a group
of scientific and commercial bodies have collaborated to
develop a process for extracting rare earths from
phosphogypsum, a form of gypsum formed as a byproduct from
treating phosphate ore with sulphuric acid to produce
fertiliser.
The project involved Russia’s National Research
Technological University (MISA), the Institute of Chemical
Technology, nuclear energy company Rosatom and chemical
engineering firm, Skygrad.
Rostec, Russia’s state-owned high tech company
and the largest consumer of rare earths in Russia, has also
expressed an interest in the project.
Estimates by the researchers suggest that Russia has
accumulated 320m tonnes of phosphogypsum waste from mineral
fertiliser production. This material typically consists of
80-98% gypsum and just 0.02% rare earths. In total, however,
this means there are 800,000 tonnes rare earths lying in
landfill around Russia.
At present, Russia consumes around 2,500 tpa rare earths of
which 1,500 tpa is imported. Russia’s industry
ministry forecasts that domestic rare earths demand will reach
5,000-7,000 tpa by 2020, while the most optimistic scenario
projects consumption could rise to 13,000 tpa. Meanwhile,
stocks of phosphogypsum are rising by 10-15m tpa.
According to MISA researchers, technology to recover rare
earths from phosphogypsum has proved successful in laboratory
scale tests and they are confident that the process will also
work at an industrial level.
"We have developed a closed-loop technology for processing
phosphogypsum using a sulphate leaching method to produce a
high-purity rare earths concentrate, containing minerals
including oxides of neodymium, dysprosium, terbium, cerium,
lanthanum and didymium," says Alexander Medvedev, one of the
leading researchers at MISA.
The rare earths concentrate is neutralised with ammonia and
separated into individual elements using special centrifugal
extractors. This step removes gypsum, phosphorus and fluorine
impurities. Calcium phosphate and fluoride byproducts from this
process can be recycled as components of chemical binders.
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Russian scientists hope to extract rare
earths from
phosphogypsum.
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Development history
Skygrad, which invented the phosphogypsum processing
technology, has been working on the process for almost a
decade. Five years ago, having produced its first batch of
mixed rare earths concentrate, the company attempted to sell
this material as a raw product.
Even though rare earths prices were at record levels in
2011, Skygrad’s efforts to commercialise the
concentrate were not successful.
"In our early studies, we really thought the production of a
rare earths concentrate was a good self-contained result,"
recalls Skygrad’s founder, Yuri Sobol. "However,
it turned out there was no market for this type of product in
Russia and foreign producers were setting the prices of rare
earths, so we had no control over what we could ask for the
material on the international market."
Skygrad therefore had to decide whether to abandon the
project or attempt to separate the rare earths from concentrate
– an entirely new research project. "Many expert
chemists, who had previously worked on rare earths processing,
tried to discourage us from embarking on this scheme, telling
us that it was impossible to extract rare earths using
centrifuges," says Sobol.
"Every kind of rare earths separation technology is
different, since it has to take into account the peculiarity
and the composition of the concentrate. We initially succeeded
in separating cerium, a low value abundant rare earth, but this
encouraged us to try for more elements," explains Yuri
Mikhailov, vice president of the Russian Academy of Science,
who worked on the project.
Skygrad’s aim is to create a
vertically-integrated business model which processes raw
phosphogypsum into pure, saleable rare earth materials. Initial
production capacity is targeted at 2,000-4,000 tpa from a new
production facility, which the company hopes to build in the
vicinity of the Volhovsky Chemical Plant, a fertiliser
manufacturing facility in Moscow Oblast, close to large
landfills of phosphogypsum.
However, according to Sobol, it has been difficult to
negotiate waste supply agreements with Russian fertiliser
companies.
"We once offered our technology to the CEO of a fertiliser
plant to recycle its waste. We asked if we could build our
facility on land belonging to the plant, which would save him
the headache of disposing of the waste, but all he was
interested in was profiting from the agreement – we
can’t do business with people who are only
interested in that," Sobol says.
Sobol claims that, once built, Skygrad’s
facility would be the first in Russia capable of separating
rare earths concentrate on an industrial scale. At present, all
Russia’s domestic rare earths supply is mined from
JSC Lovozero’s Lovozero mine on the Kola Peninsula
in northwest Russia. The mine produces 6,000 tpa loparite ore,
which is then processed at the OJSC Solikamsk Magnesium Plant
in Russia’s Perm region. This facility yields
around 1,500 tpa rare earth
concentrate, which is sent to be separated at JSC Silmet in
Estonia and LLP Irtysh Rare-Earth Co. in Kazakhstan.
"No matter how hard we’ve tried to produce
large amounts of separated rare earths domestically, without
establishing modern separation facilities in the country, the
industry will not be able to move forward," warns Sobol.
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Detractors say that logistics costs may
undermine the profitability of the venture if it is
built in Moscow.
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State support
MISA’s Medvedev is optimistic that the venture
with Skygrad will be eligible for subsidies from the Russian
government, since it offers both waste recycling and import
substitution. From 1 January 2017, the government will
introduce a new environmental tax on pollution-generating
businesses, which will be used to help fund clean technology
initiatives.
"Each application for subsidies is considered individually
and the [Skygrad project] has a good chance of qualifying for
support," says Sergei Sysoev, a spokesperson for
Russia’s Industry Ministry.
Additionally, the project could receive some support from a
Russian rouble (R) 145bn ($2.18bn*) government fund set up for
"special purposes", including providing backing for several
proposed rare earths mines in Russia.
This scheme is designed to encourage public-private
participation in Russian industry, however the
country’s faltering economy has so far scuppered
the implementation of this plan, since potential financiers are
wary of what are perceived as risky investments.
"There is no point embarking upon large-scale mining
projects in Republic of Yakutia, or in Murmansk Oblast in the
Arctic Circle where largest Russian rare earths deposits are
located, simply because they will require huge sums of money
which will take too long to repay," says Kirill Arhipov, a
Russian geologist and a member of Russian Academy of Science.
"I think the government should shift its focus to processing
projects, since these at the moment these appear much more
promising."
Skygrad’s Sobol also believes that state cash
should be targeted at the science behind rare earths
separation, to foster the development of new skills and
technology in Russia.
He suggests that the government can also help innovative
startup businesses by offering to lease them empty government
buildings, which could be converted into laboratories and test
centres.
Piloting phosphogypsum processing
A pilot project for processing phosphogypsum for rare earths
was launched earlier this year and the first batch of
commercial product should be received by the end of 2016. After
that, the team behind the project will work to optimise costs
and evaluate the potential for a large scale processing
plant.
"The pilot plant was designed to process 60 tpa
phosphogypsum, to produce rare earths concentrate and
construction-grade gypsum," explains Sobol. "The main
advantages of the proposed flowsheet are that it is a wasteless
technology and consumes relatively small amounts of reagents
and water, compared to existing technologies."
However, there are still a number of complications in
implementing the project. Several scientific observers have
warned that the new technology could be harmful to human
health, particularly for staff employed at the processing
facility, since rare earths waste can generate excessive levels
of radiation.
Other detractors have said that logistics costs are likely
to undermine the profitability of the venture if it is built in
Moscow Oblast, because once the area’s reserves of
phosphogypsum have been used up, large quantities will need to
be brought in from other parts of Russia.
The project’s supporters are nevertheless
determined to take their phosphogypsum processing technology
forward. The first batches of high-purity cerium oxide (CeO
≥99.5%) have been obtained and the researchers are working
to produce batches of other rare earth oxides which can be
offered to downstream consumers for testing.
Until this happens, however, Skygrad and MISA’s
ambitious scheme to turn mineral waste into a valuable
secondary source of rare earths is likely to be chalked up
among Russia’s growing list of metallurgical
curiosities.
*Conversion made July 2016