Can Critical Metals for Renewable Energy Products be Found in Existing
Mines? New Research Says Yes
Denver, Colo., USA: Ramping up renewable energy products will require a
range of critical metals. One of these elements, tellurium, is gaining in
popularity for use in photovoltaics, or solar panels. As global demand for
solar panels continues to increase, so is the need for critical metals like
tellurium.
Tellurium isn’t mined as a solo mineral. Currently, most tellurium is
collected as a by-product from copper mining. “The fundamental question is:
how much tellurium is out there?” says
Simon Jowitt, economic geologist at University of Nevada Las Vegas. He and coauthor Brian McNulty are
trying to find out where this tellurium is and how much metal could be
there. Jowitt is
presenting
their work at the Geological Society of America annual meeting tomorrow.
Unfortunately, the amount of tellurium in a mine is rarely reported. To
fill in the gaps and create estimates of critical minerals, Jowitt and
McNulty developed proxies to estimate tellurium content globally.
Their first proxy results from Resource and Reserve estimates. In these
reports, a mining company uses their own investigation data and estimates
that there are X-million tons of metal in the ground. These reports are
used to estimate the value of a mine site.
“We what we do is take that information—which tells us how big the deposit
is, how many million tons of ore or mineralization—and we combine that with
information that’s published elsewhere on the concentration of tellurium
and the deposit,” says Jowitt. The researchers can then calculate an
estimate for tellurium.
“The second proxy is where we know the size of the deposit,” Jowitt says.
In this case, the team uses the amounts of related tellurium minerals like
calaverite, a gold-tellurium metal. “We can estimate the amount of
tellurium in that mineral, combine that with the reported size of the
deposit, and again, develop a proxy.”
They looked at 518 mineral deposits in active mines in the U.S. and Canada
that are known to contain tellurium. Using their proxies, the researchers
calculated that 18 gold mines in the two countries could produce ~90
tons/year of tellurium from current mining, with another six copper, zinc,
and nickel mines in Canada having the potential to produce ~170 tons per
year of tellurium. Jowitt says this is a minimum estimate, because not
every gold, copper, and nickel mine in the U.S. and Canada had appropriate
data available.
By these estimates, they found that mines move around 260 tons of
tellurium, but they don’t collect it. “If you recovered that tellurium, you
could bump up global tellurium production by about 25%,” says Jowitt.
“That’s about seventeen and a half million dollars of tellurium that’s
being moved around by the minerals industry but is being lost to waste.”
Jowitt notes that their tellurium study is just one example for the
potential of extracting critical metals from existing mining operations.
“There’s a whole range of byproduct and co-product elements that are we
moving around when mining,” he says. “We need to do better making mineral
mining operations more sustainable by extracting what we can from existing
mineral deposits. And if we do that, it’s good for the environment, it’s
good for the minerals industry (the way it’s being viewed), and it’s good
for company bottom lines.”
While their study focused on active mines, Jowitt notes that extracting
critical metals from spoils piles in old mines can be another win-win
situation. “There’s a whole scope for extracting all sorts of metals from
mining waste,” he says. Old tailings and slag have potential for metal
extraction. “There’s potential for all sorts of wealth from waste,” he
says. While extracting metals from tailings can be economically profitable,
there’s also an environmental benefit.
“A whole load of these sites are environmentally problematic. So what you
do is essentially reprocess an environmentally problematic waste pile or
tailings pile, you remove the environmental problem, and use the revenue
generated from the process,” Jowitt explains. “It’s not-for-profit
mining—the value of the stuff you extract is being incorporated into the
mining operations and actually reducing the environmental harm.”
Jowitt says that as the need for carbon-neutral technologies increase,
companies will have to consider mining multiple critical metals at once.
“The demand estimates for some of these metals are just huge,” says Jowitt.
“Unless we start thinking about [mineral extraction] in these kinds of
ways, we’re going to end up with situations where metal prices start
skyrocketing and climate change mitigation starts slowing down.”
Contact: Simon Jowitt, University of Nevada Las Vegas, simon.jowitt@unlv.edu
Paper No. 212-3:
Can critical metal supply problems be solved using existing but hidden
materials flows? Tellurium and the USA-Canadian mining value chain
https://gsa.confex.com/gsa/2022AM/meetingapp.cgi/Paper/378325
Wednesday, 12 Oct. 2022, 8:35 a.m. MDT
Session 212-D1. Recent Advances in Economic Geology
https://gsa.confex.com/gsa/2022AM/meetingapp.cgi/Session/53718
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