This is geology B with Oliver's trampled.
The lithium-ion battery was invented about 40 years ago and
is now commonplace in a range of products from smartphones to
electric cars. But if we are to meet the carbon
emission goals, that governments are setting electrification and
with it, the need for electricity storage will
increase dramatically. Although many new electricity
storage methods are being developed.
None are as mature as the lithium-ion battery which will
therefore need to be a major part.
Part of a carbon-free infrastructure.
Catherine. Good enough is principal
geologist at the British Geological Survey.
She studies the geology of critical raw materials and
particularly of lithium. She's the principal investigator
for the lithium for future technology and international
Consortium. That investigates all type of
lithium deposits and how they can be extracted sustainably.
Katherine, good enough. Welcome to geology B.
Thanks very much, Oliver, thank you for having me.
Let's start with some basics. What exactly is lithium.
Lithium is a metal. In fact, it's the latest of All
Metals, it has an atomic number of just three what properties
make it. So useful for making
high-capacity batteries or lithium is unusual because it's
very reactive. Many of us may have seen lithium
in our school chemistry labs and seeing what happens to it when
it comes into contact with water for example it releases its
electrons very easily and that means that it has a Excellent,
electrical conductivity and low resistivity.
So it's very useful for using batteries and do.
There's nothing else quite like it.
So how does lithium occur naturally in the earth?
Well because it's so reactive. It doesn't occur as just
Elemental, lithium in rocks. It forms a whole range of
different minerals. So those minerals are compounds,
they might contain a lot of silica, for example, or a lot of
phosphate and it's a very wide-ranging family.
Of these naturally occurring, lithium minerals with unusual
names that Spud, you mean Peta, light, and bigger night and
lepidolite. But even in rocks that are less
rich in lithium, you will find small amounts of lithium where
it substitutes for other elements, such as magnesium in
more common minerals, and then in water, lithium ions are very
soluble. So lithium can also occur in
brines and indeed. In the seawater, there's quite a
substantial amount of lithium. So in the seawater, is it also
in the form of chemical compounds or is it in a pure
ionic State? Yes, your occurs in my your next
date and you can also get formation of lithium salts like
lithium chloride. If we're mining lithium in the
form of one of these exotic sounding minerals that you
mentioned we still have to actually extract the lithium
itself from the mineral. That's right.
This is a large part of mining when you go to my Lithium what
you actually do is dig up a rock, which contains lithium
minerals and a whole range of other minerals.
Then you have to separate the lithium minerals from the other
minerals and create a lithium mineral concentrate.
But even that concentrate may only contain a few percent of
lithium. Then we've actually got to break
open that mineral concentrate usually using significant
amounts of chemicals and actually remove the lithium from
the mineral and then will produce a chemical such as a
pure lithium carbonate or lithium hydroxide, which can
then be used in the battery supply chain.
So mining is really only the very first step.
There's usually a lot of mineral processing to be done afterwards
if you're mining, lithium from a brine that mineral processing is
perhaps a bit easier but there is still an element of mineral
processing. That's simply can't be avoided.
Does it take a lot of energy to prize?
Lithium out of the minerals. It does indeed take either a lot
of energy or some very strong chemicals, or both and
researches on going to try and develop better ways of
processing. These minerals.
I want to ask you about the geological settings in which we
find lithium and you've already mentioned the see, what about
though, mythological or Rock based settings.
The main source of lithium. If you like from Hard Rock's is
in granitic pegmatites. It's pegmatites are very
coarse-grained. Igneous rocks.
They're typically granitic and composition and they can be
found all over the world. Most commonly in areas where
you've had crustal thickening, due to mountain, building
pegmatites can just be quartz feldspar and not a lot else, but
a small subset of pegmatites are lithium enriched, and that's the
major source of hard rock lithium.
We do also find this I am in sedimentary sources.
So what would have been ancient basins that might have had
lithium enriched brines circulating in them?
And in those areas we can get lithium in lithium enriched
Clays or in boring minerals and then also brine.
Exactly Brian's are a very important source of lithium and
there's two main types of brains.
The one that's currently used for extraction.
The lithium is Brian's in the salt.
Lakes chiefly, in South America, where you have closed basins in
which binds rich in lithium concentrate, and then solar
evaporation in an area. That's particularly dry leads to
the concentration of the lithium and then you can extract from
these what I really salty Waters, you can extract the
lithium the other opportunity is where you have, what's called
geothermal or perhaps oilfield brains, where you have Brian
circulating. The Rogues.
And those may also be enriched in lithium in certain settings.
For example, here in the UK, we have frien's and Cornwall that
are known to be enriched in lithium circulating in what were
quite, lithium and Rich, granite's.
And those are also a potential source of lithium, but those
geothermal Brains, it's harder to get the lithium out of them
because, of course, you can't use solar evaporation as a
technique. So there's been a lot of
research in recent years, to develop.
Philip what's known as direct lithium extraction but you can
remove the lithium from those brines without having to
concentrate it by evaporation first.
So do The Brines get their lithium by leaching out rocks,
either the pegmatites or the sedimentary rocks.
So that's a really good question and one that I think we don't
fully know the answer to. But what seems most likely is
that the brains get their lithium, and this is the case
whether we're talking about the Salazar, The, we're talking
about geothermal brains, they get their lithium by leaching,
lithium out of very large volumes of not, especially
lithium enriched rocks. So for example, in South America
in the sellers, The Watershed surrounding them are typically,
volcanic frogs because much of the Andes is a chain of
volcanoes formed above a subduction zone and these
volcanic rocks will contain some lithium but it's not enriched
enough to be economic in the Rocks.
But If you have ground water circulating and surface water
circulating and leeching all the lithium that is in those rocks
and then collecting in a closed Basin that can be enough to
generate enrichment of lithium in the brains essentially,
because the lithium ions are so soluble in the water that they
would far rather be in the water than in the Rock and so they
will go into the water fairly quickly.
Okay, let's talk a bit more about the geological processes
that concentrate. The lithium in the highwomen.
Drock cases. First of all, the Pegman titik,
granitic rocks the way that you get lithium into a granitic
magma, is by melting sedimentary rocks that were themselves in
which their lithium exactly what type of sedimentary rocks.
Those are we're still not have to say, completely clear.
And then once you've melted those sedimentary rocks, there's
a big question around. How lithium pegmatite They are
formed, and there's two possible answers, when is you have a
large volume of magma, that forms a granite body.
And that Granite starts to crystallize that you get
fractional crystallization so your magma revolves and the
lithium remains in that magma. While everything else is
crystallizing until you have a very, very lithium enriched,
kind of residual magma and that forms the pegmatites.
That's one possibility. The other possibility is that
actually as soon as you get melting off of lithium and Rich
sedimentary rocks these relatively small amounts of melt
can gather together in the crust and form, the relatively small
bodies that are pegmatites. And when I say relatively small,
they're usually tends, perhaps hundreds of meters thick at
most, and they might extend for hundreds of meters to a
kilometer or so that's quite small by geological standards.
So we don't really understand exactly what the process is.
We know that the must be a lithium rich source, probably a
sedimentary rock that melts because the crust is being
placed under compression and being heated in a mountain belt.
And then that must form a magma that has lithium in it.
And then there are a couple of different ways in which that
magma could potentially evolve to produce lithium in which
pegmatites. So I think the real answer is,
there's quite a lot, we don't know.
So seems like Of this ignorance. If you like extends back to the
sedimentary rocks themselves, which is one of the explanations
for the source of the lithium in your magnetic granite's.
So do we know how sedimentary rocks to get enriched in their,
lithium content again, there was some uncertainty, there's no
doubt about that. We can see what's going on at
the moment. Of course, the present is the
key to the past and we can see the current sellers in the Andes
and we can imagine that if they weren't having having their
lithium extracted. Then those would sit there as
Salt Lakes and they would eventually form solids or layers
in the geological record and those solid sort layers would be
imaged in lithium, of course, that type of layer can be
recognized in some places in the geological record and perhaps we
can see that in these cases there is enrichment and lithium.
But of course the Salt, Lake's are relatively unusual because
of the solar evaporation, you need to form them.
What's much more likely is it in most cases?
We've got lithium being washed into more ordinary Lakes where
it's being deposited in association with Clay minerals
and that gives you the sedimentary rocks that we see
for example in Nevada. Tesla has talked about
potentially getting involved in mining.
So we understand how you might form those lithium in which
Clays. But then of course, what happens
to those when they get compressed and heated and
eventually Melted in a mountain belt, we don't actually know at
the moment. What a lithium enrich clay would
look like once it's become metamorphosed and partially
melted. The other thing that we're still
trying to understand is that some of the most important
sedimentary deposits of lithium like particularly the yard are
deposit in Serbia. These may be original
sedimentary rocks that may have had some lithium enrichment but
that then had Hydrothermal brine circulating through them and
enriching them further in lithium for example in Nevada,
the lithium enriched Clay's are actually in a volcanic setting
and so we would have had for chemic Waters.
If you like that might have had lithium in them.
Circulating amongst these Clays, do the various minerals in which
the lithium manifest itself. Give us any clues as to how the
lithium got there. They give us some Clues and in
particular the There's been a lot of really good experimental
work done to show you, exactly, which of the lithium minerals,
you get depends on the pressure and temperature.
So for example, there's two major minerals, what you mean
and Petty light that you find in pegmatites and of those Peta.
Light is formed at higher temperatures than spot.
You mean is so you can estimate something about the
temperatures, they formed out, and the depths that they formed
at from the minerals that you can see.
But one of the things that is really interesting about lithium
Closes is this idea of hydrothermal fluids circulating
that contain lithium and we see that consistently the brains, of
course, hydrothermal fluids themselves and in sedimentary
deposits and in pegmatites, we see evidence of these
hydrothermal fluids circulating and altering the original
minerals. And as a result, the original
processes by which either the sedimentary deposit or the
pegmatite formed have been obliterated by later.
The hydrothermal alteration. Let's talk about the commercial
extraction of lithium. Do we extract it from all three
other? Contexts, you mentioned,
pegmatite sedimentary rocks and Brian's at the moment.
Pretty much all of the words. Lithium comes from pegmatites
and from Brian's. The brains are largely mind in
South America, particularly in Chile and Argentina.
Although there is also some brine extraction in other
countries, particularly China and the SA.
Pegmatites our mind in particular in Australia.
Again, there is some mining in China from pegmatites and also a
few other countries. Currently, we are not extracting
any lithium on a commercial basis from sedimentary deposits.
Although, it's looking very likely that that will change
quite soon. So, particularly in Nevada, and
in Serbia, there are big and now World characterized sedimentary
deposits that are moving. Towards development.
And also there's currently no commercial scale extraction of
lithium from geothermal brains. But again, that's something that
is moving fairly rapidly towards development.
As our demand for lithium increases dramatically.
As we expect certainly within a decade where is the additional
lithium going to come from. So at the moment, it's coming
from ramp up of existing production more production from
Then I was in South America and increased production in
particular from pegmatites in Western Australia, but it is
very likely that we're going to see increasing, diversity of the
types of deposits that are being mined, and the locations of the
deposits that that are being mined.
There are lithium pegmatites on every continent.
I don't expect, we'll be seeing any mining in Antarctica anytime
soon, but I think it's reasonable to think that all
other continents will have lithium pegmatites being mined
to a reasonable scale within a decade or two.
It's very likely that we will see some of these big
sedimentary deposits being mind. Certainly Rio Tinto has
recently, committed quite a lot of money to developing his had
our deposit in Serbia, and then, of course, the geothermal
Brian's, if the Technologies can be developed to do that.
Really well to actually be able to extract lithium directly from
geothermal Brian's, perhaps in. With geothermal power plants,
then that has the potential to be a really excellent way of
obtaining, some of our lithium. So there is enough lithium out
there to meet our projected demand, there is absolutely no
shortage of lithium and what's more, we know many of the places
that we could go to mine, it scarcity of lithium and the
crust is not really an issue. The issues that we have at the
moment are much more social environmental, their engineering
issues their economic Issues to actually open a mine takes 10
years. First of all, you have to really
understand the resource that you have, you have to bring in
investment to get that funded. You have to develop your flow,
sheets for mineral processing and you have to find somebody
who's willing to buy whatever product it is that you can make
often a mineral concentrate for example, and to do all of that
to get the investment in line with the setup of the
engineering. And with all of the Into a
permitting. And so on takes a long while and
right now we're expecting lithium demand to increase
significantly. But we're not seeing new mines
opening at the same rate. So many of the commentators I
saying that we might see issues around Supply in the short term
which would drive higher prices which would then drive opening
of new mines. So the issues are not anything
to do with scarcity. The issues are around.
How we manage the environmental impacts, how we manage the
economics, how we manage the engineering?
There have been some much publicized cases of lithium ion
batteries, Catching Fire, but the problem seems to be never
come nonetheless, there is always scope for future
Improvement in battery capacity, speed of charging longevity, and
so on, do you think lithium will at some point be displaced by
new battery technologies? There is obviously a A lot of
research going on and a lot of interest in developing new
battery technologies, but I think the really important point
is that whatever technology is being used.
It's going to need raw materials, whether we need
sodium, whether we need Vanadium, whether we need
lithium, whichever room materials we use.
We're going to need some raw materials for batteries for
energy storage and those raw materials at least at first are
going to have to be mind because there is no other way of
producing them. Recycling can become important
down the track when there's a lot of batteries in use and
available for recycling, but at first, we're going to have to
mine them. So mining is going to be really
important, whatever technology becomes the leading technology
for Batteries Catherine. Good enough.
Thank you very much. Thank you Oliver.
It's interesting talking to you. for more about geology b, as
well as pictures and illustrations, that support this
podcast, you can go to geology B.com