Latest / PlanetGeo: The Geology Podcast / Making Batteries: The Geology of Lithium
Transcript
- 0:03SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
- 0:14SPEAKER_00: Hey Jesse, how are you doing today?
- 0:16SPEAKER_00: Chris, what's up, man?
- 0:18SPEAKER_00: Nothing.
- 0:19SPEAKER_00: Things are going well.
- 0:19SPEAKER_00: It's a beautiful day outside, but I'm looking across you, and I gotta ask, uh what Jesse do I have today?
- 0:26SPEAKER_00: Do I do I get fun Jesse or do I get boring?
- 0:29SPEAKER_00: What do I get?
- 0:30SPEAKER_01: You're on the way to Fun Jesse.
- 0:31SPEAKER_01: He'll show up in a couple minutes here.
- 0:32SPEAKER_01: I've just been working on a paper, revising a paper based on reviewer comments, which is always a little bit it's a shot to the ego, but it's also like really good and you gotta think deeply.
- 0:43SPEAKER_01: So anyway, I'm coming out of that.
- 0:45SPEAKER_01: I'm ready, I'm excited to record Planet Geo.
- 0:48SPEAKER_00: Hold on a second though.
- 0:49SPEAKER_00: Did we get an update?
- 0:51SPEAKER_01: No, um unfortunately, this is that paper is has been resubmitted, the one I was talking about uh months ago, right?
- 0:58SPEAKER_01: So yeah, that was Tell me about this.
- 1:00SPEAKER_01: Well, it's been resubmitted, and we responded, I think, fairly well to most of the comments.
- 1:06SPEAKER_01: And you'll get an update in a couple months, hopefully.
- 1:09SPEAKER_01: Now we're waiting again.
- 1:10SPEAKER_01: Back to waiting.
- 1:11SPEAKER_00: It's it's a little bit like this is a great segue because today we're talking about lithium, and maybe Jesse is feeling a little down and out today.
- 1:21SPEAKER_01: That's true.
- 1:22SPEAKER_01: Yeah, so that's a great point, Chris.
- 1:24SPEAKER_01: The lithium, I think, I don't know, maybe most people know this, at least I knew this.
- 1:28SPEAKER_01: Uh maybe it's just because my wife's a medical doctor, but lithium in the medical community is used to treat bipolar disorders like lithium carbonate or lithium metal, but lithium has really arrived on the scene in the public sort of mental space recently due to battery storage.
- 1:46SPEAKER_00: Yeah, for sure.
- 1:47SPEAKER_00: So are we going to do introductions today?
- 1:49SPEAKER_00: We're just going to jump right into lithium.
- 1:50SPEAKER_00: What are we doing?
- 1:51SPEAKER_01: Well, let's go for it.
- 1:51SPEAKER_01: You're Chris Bullheis, national award-winning high school earth science teacher from the great state of Michigan, my former teacher.
- 1:58SPEAKER_01: That's all I got to say about you today.
- 2:00SPEAKER_01: Maybe I'll have more to say later.
- 2:01SPEAKER_00: Okay, well, you're Dr.
- 2:02SPEAKER_00: Jesse Rymanck, and you were one of my former students.
- 2:06SPEAKER_00: You just said that, but then you went on and got your PhD in geology from the University of Alberta up in Canada.
- 2:13SPEAKER_00: And then you you now work at one of the best geology departments in the country.
- 2:18SPEAKER_00: I mean, you're you're a professor at Penn State and uh in the geoscience department.
- 2:21SPEAKER_00: That's a that's a top-tier program, and that's impressive.
- 2:24SPEAKER_00: So you don't get that a lot from me, Jesse, but you're rather impressive.
- 2:28SPEAKER_01: So well, you're just trying to build me up and get fun Jesse out, aren't you?
- 2:33SPEAKER_00: That's that's all I want.
- 2:35SPEAKER_00: I don't like grumpy Jesse.
- 2:36SPEAKER_00: I don't like boring.
- 2:37SPEAKER_00: I like I need fun Jesse here.
- 2:39SPEAKER_00: Everybody wants fun Jesse.
- 2:40SPEAKER_01: All right, fun Jesse's here.
- 2:41SPEAKER_01: All right, we're ready to go.
- 2:42SPEAKER_01: All right, fun Jesse's here.
- 2:44SPEAKER_01: Um okay.
- 2:45SPEAKER_01: I mean, this is a fun episode.
- 2:46SPEAKER_00: Hold on a second.
- 2:47SPEAKER_00: Let's go over like why is it important and then kind of what we're gonna do.
- 2:51SPEAKER_00: What's the direction for today, Jesse?
- 2:53SPEAKER_01: Yeah, we're gonna start out with why we care.
- 2:56SPEAKER_01: Why should we care about the geology of lithium?
- 2:58SPEAKER_01: But really, we're talking about the geology of lithium.
- 3:00SPEAKER_01: So we're gonna start out with why we care, why we should know about the geology of lithium.
- 3:05SPEAKER_01: Then we're gonna talk about lithium the element, what is it, some basics there, and we're really gonna spend most of the time talking about where it occurs, really, where lithium occurs, how it occurs in deposits, what we should be paying attention to when we think about sustainably mining lithium and extracting it from the ground and why we should consider the fact that we actually have to do this in the future.
- 3:25SPEAKER_00: That's right.
- 3:26SPEAKER_00: I think that's so important for everyone to know a little bit about where lithium comes from, how it forms geologically, because we need to know where these resources come from, if for nothing else, just so we know that it's kind of a rare thing.
- 3:40SPEAKER_00: Yes.
- 3:41SPEAKER_00: You know, it's a finite supply of this precious metal, and we need to know that.
- 3:45SPEAKER_00: Everybody needs to know that.
- 3:46SPEAKER_01: So lithium use has skyrocketed, and it's best you can represent this use rate any way you want, but the price of lithium has blown up the last couple years from like 10,000 US dollars per metric ton all the way up to 75,000 recently.
- 4:04SPEAKER_01: So in the course of a couple years, this has completely blown up, and the demand is coming mostly from I think most people might know this, lithium-ion batteries.
- 4:14SPEAKER_01: And batteries are everywhere.
- 4:16SPEAKER_01: We have a few little stats here.
- 4:18SPEAKER_01: Uh, your cell phone, your average cell phone, has three grams of lithium carbonate in the battery, which is about the weight of a US penny, the coin, a little penny.
- 4:27SPEAKER_00: So, Jesse, I have a question though, because we have a stat here that you know, lithium in batteries is about 75% of global lithium use.
- 4:37SPEAKER_00: Does the what's the other 25%?
- 4:39SPEAKER_00: Is that uh uh is that medical?
- 4:41SPEAKER_00: You know, where does that go?
- 4:42SPEAKER_01: Yeah, most of it comes from ceramics in glass as a doping mechanism in glasses to sort of um create the mechanical properties of any particular ceramic or glass you want.
- 4:52SPEAKER_01: Many people might know lithium grease.
- 4:55SPEAKER_01: Uh, it's a really good grease that you can use for.
- 4:58SPEAKER_01: I don't know, where have I seen lithium grease?
- 5:00SPEAKER_01: Do you know where you get lithium?
- 5:01SPEAKER_01: Is it car grease?
- 5:02SPEAKER_00: I don't know.
- 5:03SPEAKER_00: I I've seen it, but I I don't I don't know.
- 5:05SPEAKER_01: I remember using it.
- 5:06SPEAKER_01: I'm not sure if I was using it for my bike or or what was going on, but lithium grease is a couple percent uh of the uses there.
- 5:12SPEAKER_01: And so that there's small components, but a lot of it's ceramics and glass.
- 5:16SPEAKER_00: I got a guess that it was for your bike because you are about as mechanically inclined as well, well, you're not.
- 5:22SPEAKER_00: So you're not working on your car or truck, you know.
- 5:25SPEAKER_00: That's just not you.
- 5:26SPEAKER_00: I resemble that remark.
- 5:28SPEAKER_00: I know you do.
- 5:29SPEAKER_00: I know you do.
- 5:30SPEAKER_00: Hey, I have a quick fact just popped into my head.
- 5:33SPEAKER_00: Um, do you remember doing flame tests on minerals back in the old college days?
- 5:38SPEAKER_00: You know, you'd take a little chunk of a mineral and you'd torch it, and the color of the flame indicates some elemental compositions.
- 5:45SPEAKER_00: You remember that?
- 5:46SPEAKER_01: I think, Chris, that was deemed unsafe for my generation.
- 5:48SPEAKER_01: So this was you know, going back in the day when uh the older generation uh we never did that with minerals that I remember now.
- 5:56SPEAKER_00: Oh my gosh, yeah.
- 5:57SPEAKER_00: Well, we did, and lithium gives a bright red flame.
- 6:02SPEAKER_00: So that was one of the ways that we could tell if it had lithium in it and just torch it.
- 6:07SPEAKER_01: Well, so lithium is also used in electric cars, obviously.
- 6:10SPEAKER_01: Most people know that.
- 6:11SPEAKER_01: Laptops have about 30 grams of lithium in it.
- 6:13SPEAKER_01: Electric car has between 20 to 50 kilograms in it.
- 6:17SPEAKER_01: And to calibrate what a kilogram is, a big watermelon is about 10 kilograms.
- 6:23SPEAKER_00: So you having first of all, I I could take issue with this.
- 6:26SPEAKER_00: Okay, now Jesse, you have to understand.
- 6:28SPEAKER_00: I lumped watermelons for a living.
- 6:32SPEAKER_00: I was a lumper, and what that is is somebody that it's it's true.
- 6:38SPEAKER_00: This is true.
- 6:38SPEAKER_00: It's the technical term for somebody that unloads semis.
- 6:42SPEAKER_00: Okay.
- 6:42SPEAKER_00: So by hand.
- 6:44SPEAKER_00: Okay, no hilos.
- 6:45SPEAKER_00: So I um was a professional watermelon lumper, actually.
- 6:49SPEAKER_00: So they come in on the flatbeds, and I would take 50 watermelons and put them in a bin, and then the hilo would come and take the bin away.
- 6:56SPEAKER_00: And we got paid 125 bucks for two people to lump a semi-load of watermelons.
- 7:02SPEAKER_00: And it took us like we would because you know, we got paid by the job, so we were busting it.
- 7:08SPEAKER_00: Took maybe an hour and a half to two hours to lump a complete load of watermelons.
- 7:12SPEAKER_00: Depends on how fast the hilo drives.
- 7:14SPEAKER_01: All right, Chris, I don't care about this.
- 7:15SPEAKER_01: I really want to get to the fact that you were a watermelon lumper.
- 7:18SPEAKER_01: I don't care how long it took you, but you that that's a great job for you.
- 7:22SPEAKER_01: I think you should go.
- 7:23SPEAKER_00: And I'm gonna tell you right now, your stat that a watermelon is 10 kilograms is way off base.
- 7:28SPEAKER_00: That's a that would be an enormous watermelon.
- 7:31SPEAKER_01: Yeah, yeah.
- 7:31SPEAKER_01: These are giant ones.
- 7:32SPEAKER_01: This is this comes straight from the watermelon board, though.
- 7:35SPEAKER_01: A really large one weighs about 20 pounds, so a little bit less than 10 kilos.
- 7:41SPEAKER_00: How about if we just say this a kilogram is 2.2 pounds?
- 7:44SPEAKER_00: Okay, so we're talking so an electric car has maybe 50 to 100 pounds of lithium in it.
- 7:51SPEAKER_00: Wow, that's a lot.
- 7:52SPEAKER_01: It's a lot, it's a lot.
- 7:54SPEAKER_01: A lot of the weight of the uh, you know, a significant amount of the weight is the battery weight there.
- 7:58SPEAKER_01: So of just lithium in the battery, so that's not everything else.
- 8:01SPEAKER_01: So lithium has a couple different isotopes, and I love isotope geochemistry, so I can't help but insert some isotope geochemistry here.
- 8:08SPEAKER_01: Has two main isotopes.
- 8:10SPEAKER_01: Lithium has the atomic number of three, so it has three protons in the nucleus.
- 8:15SPEAKER_01: It also can have three neutrons or four neutrons, and so that's lithium-six or seven, the mass of the isotope.
- 8:22SPEAKER_00: Okay, I'm gonna back up a second.
- 8:23SPEAKER_00: Let's just give a little bit of like intro chemistry here, okay?
- 8:27SPEAKER_00: The identity of every element is based upon the number of protons that are in the nucleus.
- 8:32SPEAKER_00: And lithium has three.
- 8:33SPEAKER_00: So it's atomic number three on the periodic table, and that's the way the periodic table is organized.
- 8:37SPEAKER_00: It's based upon the atomic number, is the number of protons that exist in it.
- 8:42SPEAKER_00: So it's the identity of the element.
- 8:44SPEAKER_00: Now, when you you say isotopes, there are two main isotopes of lithium.
- 8:49SPEAKER_00: There's lithium-6 and lithium-7.
- 8:52SPEAKER_00: What makes them both lithium is that both of these isotopes have three protons in the nucleus.
- 8:58SPEAKER_00: So the difference between them then is that lithium-6 has three neutrons with the protons in the nucleus, and lithium-7 has four neutrons.
- 9:08SPEAKER_00: So that's the only difference between them is the number of neutrons.
- 9:12SPEAKER_00: We talk about that all the time when we get into like nuclear chemistry.
- 9:15SPEAKER_00: You're talking about different numbers of neutrons for the same element, which means it has the same number of protons.
- 9:22SPEAKER_01: That is exactly right.
- 9:23SPEAKER_01: And lithium exists in your periodic table.
- 9:25SPEAKER_01: Remember, you know, picture this in your head.
- 9:27SPEAKER_01: Remember back to high school chemistry class, it's in the top left side of the periodic table, right below hydrogen.
- 9:33SPEAKER_01: So the reason we bring up isotopes here is that lithium is really important for nuclear reactors.
- 9:37SPEAKER_01: And lithium-7 is actually used to cool reactors because it can absorb neutrons.
- 9:43SPEAKER_01: So it's used in molten salt reactors, sort of this new generation of reactors.
- 9:47SPEAKER_01: Lithium-6 is a nice fusion material.
- 9:52SPEAKER_01: So basically, lithium-6 can absorb a neutron, it'll absorb a neutron and then it can fission right away to produce tritium, which is a great fuel for fusion reactions.
- 10:01SPEAKER_00: So I have a question for you then on that lithium-6 absorbs a neutron, so it becomes lithium-7, then, right?
- 10:08SPEAKER_01: That's right.
- 10:09SPEAKER_00: Okay, so lithium-6 absorbs a neutron, becomes lithium-7, and then it it fissions.
- 10:14SPEAKER_00: Like what does that look like?
- 10:16SPEAKER_00: Why does it fission?
- 10:17SPEAKER_00: Is is it getting hit with a with another neutron, or does it just spontaneously if it gets hit with a high enough energy neutron?
- 10:24SPEAKER_01: So lithium-6 can get hit with a high energy neutron and then split, basically.
- 10:28SPEAKER_01: So it depends on the energy of the neutron coming in to it, basically.
- 10:33SPEAKER_01: And lithium was used in actually the US's biggest thermonuclear weapons test ever, which was the Bravo test on bikini atoll, which is infamous uh now because it was too big, basically.
- 10:44SPEAKER_01: So anyway, you they used lithium.
- 10:46SPEAKER_00: Okay, so we're getting hold on, we're getting into the weeds here.
- 10:48SPEAKER_00: Um, let's move on into to you know, why do we care because there's a lot of cool stuff we could talk about, but we need to move on.
- 10:55SPEAKER_00: So lithium prices have skyrocketed.
- 10:58SPEAKER_00: I think everybody is pretty much aware of that, like everything else is skyrocketing right now.
- 11:02SPEAKER_00: And lithium demand could grow by as much as 30% per year over the next seven to eight years.
- 11:09SPEAKER_00: That's amazing and scary all at the same time.
- 11:13SPEAKER_01: Yeah, and so that's kind of why we're focused on lithium and the geology of lithium here is we don't have enough mineable resources right now to get that demand, so to compensate for that demand.
- 11:23SPEAKER_01: So, Chris, I think we need to do a little bit more chemistry on lithium itself, and I would call this geochemistry, lithium in relation to where it exists on Earth, and then we'll get into the geology and sort of more specific.
- 11:36SPEAKER_01: And so we mentioned this before, it's right below hydrogen on the periodic table, which means it's light or heavy when it's that high up on the periodic table.
- 11:45SPEAKER_00: Yeah, it's extremely light, it's the lightest metal in solid form that we have on planet Earth.
- 11:53SPEAKER_00: And it's also very reactive, which means that we don't find it alone a lot.
- 11:59SPEAKER_00: We almost always find it combined with other minerals, which is different from like the native elements when we talk about copper and gold and silver that we tend to find alone because they're very non-reactive native elements, whereas lithium is exceedingly reactive.
- 12:15SPEAKER_01: And it's interesting, the low density aspect, pure lithium metal, which you said we never find on Earth, like we don't ever find pure lithium metal unless we make it as humans, that'll float on water.
- 12:25SPEAKER_01: It's so light, it has such low density.
- 12:27SPEAKER_01: Yeah, that's it's amazing.
- 12:28SPEAKER_01: But lithium is a really low concentration in the entire earth, and we're talking two parts per billion.
- 12:36SPEAKER_01: If you average out the entire earth, that's the crust, the mantle, the core, two parts per billion.
- 12:42SPEAKER_00: Now, we talked previously about Hold on, I want to ask the listeners a second just to think about something and and like what they may have learned as they've gone through our other podcasts.
- 12:53SPEAKER_00: Hopefully they would know the answer to this question.
- 12:55SPEAKER_00: But okay, so it's two parts per billion when you take the entire earth.
- 13:01SPEAKER_00: But knowing what we know about the way the earth is differentiated and layered and so on, where would you expect lithium to be in the highest concentration?
- 13:13SPEAKER_00: Would you expect it to be in the crust of the earth, in the mantle of the earth, or in the core of the earth?
- 13:19SPEAKER_00: Just throwing that out there for the listeners.
- 13:22SPEAKER_01: That's a great question, Chris, because we talked previously about the geology of iridium, which is this great meteorite tracer, right?
- 13:28SPEAKER_01: And we talked about how iridium is concentrated in the cores.
- 13:31SPEAKER_01: It's concentrated in the metal, and that's why meteorites bring it in, and meteorites have a high iridium core, and they sort of spread iridium around, and we can use it as a tracer.
- 13:39SPEAKER_01: Lithium's actually the opposite, it gets concentrated in the continental crust.
- 13:43SPEAKER_01: So lithium is actually, and we'll kind of come to this in the geology part.
- 13:46SPEAKER_01: Lithium is actually this like extreme distillate on Earth.
- 13:51SPEAKER_01: So it gets distilled every time the earth partially melts, it gets distilled higher and higher and higher.
- 13:57SPEAKER_01: So if we think about the earth, we have the core, then we have the mantle.
- 14:01SPEAKER_01: Okay, that's the first sort of category.
- 14:02SPEAKER_01: If you melt the mantle, you form oceanic crust.
- 14:05SPEAKER_01: That's a distillation step.
- 14:06SPEAKER_01: So you increase lithium there, you form basalt.
- 14:09SPEAKER_01: You melt the oceanic crust and you form continental crust.
- 14:13SPEAKER_01: Generally, that's oversimplification.
- 14:15SPEAKER_01: But the continental crust is enriched in lithium.
- 14:19SPEAKER_01: It has 20 parts per million.
- 14:21SPEAKER_01: So the whole earth is two out of a billion atoms are lithium.
- 14:25SPEAKER_01: In the continental crust, we have 20 parts per million.
- 14:28SPEAKER_01: 20 out of a million are lithium, which is a much higher concentration.
- 14:32SPEAKER_00: You just got really professory on us.
- 14:34SPEAKER_00: Basically, where I was going with this.
- 14:36SPEAKER_00: Holy cow.
- 14:36SPEAKER_00: All I was saying is it's exceedingly light, it's exceedingly less, you know, low density, and that fits the layering of the earth, the structure of the earth.
- 14:46SPEAKER_00: So you would expect that lithium would be at much higher concentration in the crust than you would deeper inside the earth.
- 14:53SPEAKER_00: So that's where I was going.
- 14:55SPEAKER_00: Holy crap.
- 14:56SPEAKER_00: Um, you decided to get really doctory on us there, but that's okay.
- 15:00SPEAKER_00: Good job, Jesse.
- 15:00SPEAKER_00: Good job.
- 15:01SPEAKER_01: Let's uh on that note then, let's step back out and think about the geology of lithium.
- 15:06SPEAKER_01: Where does lithium occur on Earth in the continental crust?
- 15:08SPEAKER_01: Like we already talked about it's really concentrated in the continental crust.
- 15:11SPEAKER_01: Where in the continental crust does it occur?
- 15:13SPEAKER_00: Yes, this is something that you and I both love.
- 15:17SPEAKER_00: Lithium is found in both pegmatites, which we're gonna talk about here in a minute, and we're also gonna talk about brines.
- 15:24SPEAKER_00: So pegmatites and brines, that's where we find concentrated lithium.
- 15:29SPEAKER_00: In other words, like a lithium ore.
- 15:31SPEAKER_01: And there's an up-and-coming resource of lithium or location for resource, but it's really related to brines as well.
- 15:38SPEAKER_01: So we'll kind of group sedimentary rocks and brines kind of together in this context.
- 15:43SPEAKER_01: But Chris, uh, you and I, I mean, I think we is it fair to say that we love lithium minerals because we have spent a lot of time collecting lithium minerals before in pegmatites.
- 15:53SPEAKER_00: We have actually um we've gotten lithium.
- 15:55SPEAKER_00: I think I know we got spodgmine in the Black Hills.
- 15:59SPEAKER_00: Did we also get Lapidolite in the Black Hills?
- 16:01SPEAKER_00: Was that on a different trip?
- 16:02SPEAKER_01: No, I'm pretty sure it was the Black Hills.
- 16:05SPEAKER_01: It's a different mine.
- 16:06SPEAKER_01: It wasn't the Eda mine, but it was uh some other mine, I'm not sure.
- 16:10SPEAKER_00: So I want to just describe these a second to the listener.
- 16:13SPEAKER_00: Spodamine is a it tends to be like this really creamy white color mineral.
- 16:19SPEAKER_00: It has a high density, which is weird because it has lithium in it, and we just got done talking about how low density lithium is, but there are other things going on there.
- 16:27SPEAKER_00: But it's a it's a high density, light colored mineral.
- 16:30SPEAKER_01: Let me interrupt there, Chris, just for the mineral nerds.
- 16:32SPEAKER_01: It's a lithium-bearing pyroxene.
- 16:34SPEAKER_01: So it has lithium instead of having calcium, magnesium, or iron in it.
- 16:38SPEAKER_01: It has lithium and aluminum.
- 16:40SPEAKER_00: That's right, because pyroxines, if you remember from Bowen's reaction series, pyroxines tend to be very dark colored, like greenish black in color.
- 16:48SPEAKER_00: Spodgmine's the opposite of that because of the lithium that kind of takes the place of the iron and magnesium in it.
- 16:53SPEAKER_00: Anyway, okay.
- 16:54SPEAKER_00: Spodgmine, we collected this stuff.
- 16:56SPEAKER_00: Amazing.
- 16:57SPEAKER_00: I mean, I have a crystal of spodgmine that's two feet diameter, maybe.
- 17:01SPEAKER_00: I mean, that's a that's a huge, huge, huge crystal.
- 17:04SPEAKER_01: And they're this brilliant white.
- 17:06SPEAKER_01: They're really white, really light colored, have these striations in them.
- 17:09SPEAKER_01: And do you remember seeing there?
- 17:10SPEAKER_01: I forget what mine was it the edamine, but we saw this one.
- 17:12SPEAKER_01: It was the edamine for sure.
- 17:13SPEAKER_01: I mean, this thing was the size of a vehicle.
- 17:16SPEAKER_01: I mean, it's bigger than a house, probably.
- 17:18SPEAKER_01: This thing.
- 17:18SPEAKER_01: So this beautiful, huge, house-sized spodgamine crystal sticking out of the wall of this open pit old mine shaft that has the lake in the bottom and everything, like the whole nine yards.
- 17:28SPEAKER_01: And this spodgamine crystal sticking out of the wall, that was really fun.
- 17:32SPEAKER_01: I mean, spodjamine everywhere.
- 17:34SPEAKER_00: So the other mineral that I want to talk about is lipidolite.
- 17:38SPEAKER_00: You should remember that this is something that looks like um, well, it's a mica.
- 17:42SPEAKER_00: And muscovite and biotite.
- 17:43SPEAKER_00: Muscovites are like clear color or yellowish color, you know, biotite's black.
- 17:48SPEAKER_00: Lapidolite is a mica, so it's just like that, that flaky, peelable mineral that my students love to destroy.
- 17:54SPEAKER_00: Uh, but it's purple and it is absolutely gorgeous.
- 17:58SPEAKER_00: Um, you know, lepidolite is purple muscovite.
- 18:02SPEAKER_00: You know, it's it's it it's awesome.
- 18:04SPEAKER_01: And it has this really, really, really deep purple color to it.
- 18:07SPEAKER_01: When you get big books of it, it is a stunningly beautiful mineral.
- 18:11SPEAKER_00: Okay, so let's get into then lithium tends to concentrate in pegmatites.
- 18:14SPEAKER_00: Let's do a little quick rundown of how pegmatites form and you know why they have why pegmatites tend to concentrate lithium.
- 18:23SPEAKER_00: We've done an episode on this, so you, if you want the full story on pegmatites, you can go back and do a search for pegmatites because it's awesome, it's fun.
- 18:32SPEAKER_00: But pegmatites form in late, late stage cooling of a huge body of magma, like a batholith.
- 18:41SPEAKER_00: Okay, and what what happens is well, a few things.
- 18:45SPEAKER_00: In this late stage cooling, you have a lot of hot rock is that have pods of really superheated and very salty water that are getting squeezed as that rock continues to cool and contract around it.
- 19:02SPEAKER_00: Now, what kinds of salts are in this superheated water that's trapped, this like last stage cooling?
- 19:10SPEAKER_00: Jesse, what kind of salts are in there?
- 19:12SPEAKER_01: Oh, you'd have all kinds of salts, a lot of sodium, a lot of lithium in the salts.
- 19:17SPEAKER_01: This is a really, really, really reactive fluid, really reactive.
- 19:20SPEAKER_01: So it will dissolve lots of stuff in there.
- 19:24SPEAKER_00: Now, what you have though in this water is you have a concentration of elements that did not uh they didn't combine to form crystals of normal minerals because they don't fit.
- 19:38SPEAKER_00: Right?
- 19:38SPEAKER_00: They're too small, they're too big, they're not, they're just not the right fit to fit in the crystal structure of most of the common minerals, what we call the rock-forming minerals.
- 19:48SPEAKER_00: And so these elements, they don't have a place to go, so they just hang out and they hang out and they hang out, and that's why they end up as this last late stage cooling.
- 19:56SPEAKER_00: So this water is loaded with stuff like that.
- 19:59SPEAKER_00: Well, eventually you get to the point where these elements can say, basically, screw you to the rest of the common minerals.
- 20:06SPEAKER_00: We're gonna form our own minerals, and they're pretty awesome.
- 20:10SPEAKER_00: So they're rare because they're well, they're not common because they they're made up of elements that are not common.
- 20:15SPEAKER_00: And they form really massive crystals in a fairly short period of time because they're forming from water instead of forming from magma.
- 20:26SPEAKER_00: And if you imagine, you know, how easy it is for ions to zip through water and grow crystals out of that, is much easier to do from water than it is to do from magma because magma's so sticky and thick and gooey.
- 20:41SPEAKER_00: The ions just can't move fast enough.
- 20:44SPEAKER_00: So pegmatites, actually, the definition of a pegmatite is when you have crystals that are bigger than a centimeter in diameter, and there's no top end to them.
- 20:54SPEAKER_01: So they could be anywhere from a centimeter to a house.
- 20:57SPEAKER_01: I mean, that's a pretty big range of crystals, right?
- 21:00SPEAKER_00: That's right.
- 21:01SPEAKER_00: And they happen though very fast because they form in this water.
- 21:04SPEAKER_01: That's right.
- 21:05SPEAKER_01: So not all pegmatites have lithium, though.
- 21:07SPEAKER_01: And this is a really interesting part about lithium, and it goes back to this like final distillation point we were making earlier, is that think of uh subduction zone systems.
- 21:17SPEAKER_01: So where you have oceanic crust subducting beneath a continental plate, that is not really melting the continent too much.
- 21:24SPEAKER_01: It's melting the mantle beneath the continent.
- 21:26SPEAKER_01: So it's melting ultramafic rocks or mafic rocks to form intermediate rocks that are kind of halfway between basalt and granite, what we call andesite or diorites or tonalites.
- 21:38SPEAKER_01: Those are continents, but they're not granites, they're not super enriched.
- 21:41SPEAKER_01: You don't get pegmatites above those subduction zone type magmas that are enriched in lithium because the starting thing did not have enough lithium in it.
- 21:49SPEAKER_01: Where you get lithium in pegmatites is when you melt the continental crust.
- 21:54SPEAKER_01: So places like the black.
- 21:55SPEAKER_00: Hold on, Jesse.
- 21:56SPEAKER_00: I want to have you go back a second because that's such an awesome point.
- 21:59SPEAKER_00: I want to make sure that you.
- 22:00SPEAKER_00: Really clear on it.
- 22:01SPEAKER_00: You said that you don't get pegmatites from subduction zone because the source material.
- 22:07SPEAKER_00: Can you just expand upon that source material real quick?
- 22:11SPEAKER_01: So the source material to a subduction zone, magma, which is the mantle, you're melting the mantle beneath the continent there.
- 22:19SPEAKER_01: That mantle does not have a lot of lithium in it because lithium hasn't been enriched by this distillation process.
- 22:25SPEAKER_01: There's really low concentrations of lithium in the mantle.
- 22:28SPEAKER_01: So one step of enrichment, this partial melting of the mantle to form the Cascadia volcanic chain, doesn't have enough lithium.
- 22:36SPEAKER_01: That magma doesn't have very much lithium in it because you've only had one distillation step.
- 22:41SPEAKER_00: So you might get pegmatites above a subduction zone, but you're probably not going to get a lithium-enriched pegmatite above a subduction zone.
- 22:49SPEAKER_01: Right, Jess?
- 22:50SPEAKER_01: Exactly.
- 22:50SPEAKER_01: So where do we need to go to find lithium-bearing pegmatites?
- 22:53SPEAKER_01: Well, we need to go to places where the continental crust itself is being melted.
- 22:57SPEAKER_01: Places like the Black Hills of South Dakota, which we've talked about in previous episodes, the Northeast New England in the Appalachians, the Akkadian orogeny, where the continental crust itself was being melted.
- 23:08SPEAKER_01: You can melt the deep part of the continental crust, the upper part of the continental crust, whatever it is, the continental crust is stage two of distillation from the mantle.
- 23:16SPEAKER_01: And this melting of that is actually stage three.
- 23:19SPEAKER_01: So stage three of distillation, the third melting from the mantle, gives you these lithium-bearing pegmatites.
- 23:26SPEAKER_01: And so I think it's an interesting lithium is this great tracer of like how much melting have you done, how many melting steps have you done on Earth to generate lithium?
- 23:35SPEAKER_00: That's right.
- 23:36SPEAKER_00: And and here's an interesting stat.
- 23:39SPEAKER_00: The absolute highest grade lithium pegmatite deposit has only about two to three percent lithium oxide anyway.
- 23:48SPEAKER_00: So it's even being enriched like this as it is, it's still only two to three percent in a pegmatite itself.
- 23:56SPEAKER_01: That's absolutely right.
- 23:57SPEAKER_01: And there are places where lithium pegmatites are mined, mainly right now in Australia and China are the main ones.
- 24:03SPEAKER_01: But the reason that not all lithium comes from pegmatites, because two to three percent lithium oxide is it's a decent grade for an ore deposit, but that lithium is bound up in silicate minerals.
- 24:14SPEAKER_01: And these are strong minerals, lipidolite and spodamine, strong minerals, hard to break, very complicated and costly to get lithium out of the silicate minerals that it's bound up into.
- 24:25SPEAKER_01: So our spogamine crystal, Chris, your big two-foot-wide spogamine crystal that you have sitting out in your front yard, uh, that'd be pretty inefficient to get lithium out of that thing, even though it's two to three percent lithium.
- 24:37SPEAKER_01: You got to have really high concentrations to make this economical to extract the lithium from.
- 24:42SPEAKER_00: Do you remember lifting that bad boy into the back of my truck, though?
- 24:45SPEAKER_00: Yeah.
- 24:46SPEAKER_00: It took three of us.
- 24:47SPEAKER_01: That was that your truck was sagging on the way home after that.
- 24:51SPEAKER_00: It did.
- 24:51SPEAKER_00: Yeah, she was hurting after that.
- 24:53SPEAKER_00: Absolutely.
- 24:53SPEAKER_00: All right, Jesse, let's move into the other way that lithium deposits get enriched.
- 25:00SPEAKER_00: Okay, so we talked pegmatites, now we're moving into brines.
- 25:03SPEAKER_00: Jesse, define for a second what a brine is.
- 25:07SPEAKER_01: A brine is basically really, really salty water.
- 25:10SPEAKER_01: Think of pickle brine, you know, the brine in your pickle jar.
- 25:15SPEAKER_00: Salty water.
- 25:16SPEAKER_01: We had it in pegmatites, we got it in brines.
- 25:18SPEAKER_01: Exactly.
- 25:18SPEAKER_01: And so this lithium brines are really right now service about 60% of the world's supply of lithium is mining lithium brines.
- 25:27SPEAKER_01: And if we could distill this down, really simply, it's basically sucking up water that has lithium in solution and extracting the lithium from that by inducing various chemical reactions and sometimes just evaporating that water.
- 25:40SPEAKER_01: Just put it somewhere, let it evaporate, mine the lithium after that.
- 25:44SPEAKER_01: So you take lithium from some lithium-rich water, lithium-rich brine, and put it somewhere where it evaporates, we can extract the lithium from it.
- 25:54SPEAKER_00: Okay, so in order to get that, Jesse, and I'm I'm honestly asking this question here, do you need to have water circulating through crustal rocks?
- 26:02SPEAKER_00: We're not talking about ocean water here, are we?
- 26:05SPEAKER_01: Or are we?
- 26:05SPEAKER_01: Like not typically ocean water.
- 26:07SPEAKER_01: Typically, ocean water is not quite lithium-rich enough uh to do this efficiently or economically.
- 26:12SPEAKER_01: So usually we think about areas where you have restricted basins, really dry areas where these continental rocks are exposed.
- 26:22SPEAKER_01: You need to be weathering these continental rocks with high lithium content and then putting that water somewhere naturally that it can pick up as much lithium as possible and then concentrate it somewhere.
- 26:32SPEAKER_01: So, what's a restricted basin, Chris?
- 26:34SPEAKER_00: Yeah, you said a restricted basin, and and this is when you think of a restricted basin, you think of like these inputs dumping into this like low basin or like an ocean, okay?
- 26:45SPEAKER_00: Let's say this like really warm, shallow ocean basin.
- 26:49SPEAKER_00: Okay, so the warmer it is, the shallower it is, the saltier it's gonna get.
- 26:53SPEAKER_00: But now, how do you get a restricted basin?
- 26:56SPEAKER_01: Can I interrupt you there, Chris, and ask what is the input and output of water in a restricted basin, or what does the name come from?
- 27:03SPEAKER_00: Yeah, okay.
- 27:03SPEAKER_00: So inputs into a restricted basin is gonna be you know mostly rivers, okay.
- 27:08SPEAKER_00: And we talked about this in a previous episode, which is why oceans are salty to begin with.
- 27:14SPEAKER_00: Rivers are dumping these salts.
- 27:16SPEAKER_00: And so if you have the right geology where water is picking up lithium and then dumping it into this restricted basin, the only way water leaves this is through evaporation.
- 27:26SPEAKER_00: So when water leaves, the salts stay behind.
- 27:29SPEAKER_00: But what is a restricted basin?
- 27:31SPEAKER_00: This is something where you have this ocean, and then imagine a reef system offshore, let's say.
- 27:37SPEAKER_00: Okay, so in a little bit deeper water, still really warm and really shallow, but you have this reef.
- 27:42SPEAKER_00: What that does is the reef is able to keep up with fluctuating levels of water, right?
- 27:47SPEAKER_00: Well, that reef blocks the inflow of fresher water further out in deeper ocean water.
- 27:53SPEAKER_00: So it restricts the inflow and outflow of water from that one localized basin.
- 28:00SPEAKER_00: Does that make sense?
- 28:01SPEAKER_01: Absolutely.
- 28:02SPEAKER_01: That is a great description, Chris.
- 28:04SPEAKER_01: And you just described something sitting on the edge of an ocean, right?
- 28:08SPEAKER_01: So it's very close to the edges of a continent.
- 28:11SPEAKER_01: Now, that's not a great place to get lithium deposits.
- 28:15SPEAKER_01: And the reason is because the rocks being eroded into that basin are probably subduction zone like volcanic rocks or juvenile rocks.
- 28:23SPEAKER_01: We need to be in the interiors of continents where we have these old super distilled rocks exposed, high lithium content or high air lithium content, those are being eroded, weathered, and deposited in a restricted basin.
- 28:35SPEAKER_01: So the major restricted basins that are being mined right now for lithium are in Chile, Argentina, and Bolivia, the Atacama Desert.
- 28:42SPEAKER_01: High desert, very dry, lots of evaporation, lots of lithium-bearing rocks around because it's in the interior of the South American continent, which is bringing all this lithium and basically concentrating it in these deposits, in these brines.
- 28:56SPEAKER_00: Are we talking about playas then, basically?
- 28:58SPEAKER_01: Yeah, they're kind of like playas.
- 29:00SPEAKER_01: Yes, exactly.
- 29:01SPEAKER_01: And so what actually happens is you basically either drill in, pump out these brines that are circulating beneath the surface, or just take the natural sediments that are being eroded in the water that's coming down and concentrate those in basins, sort of make little ponds that you can evaporate, maybe add some chemicals to induce lithium to deposit uh separate from other elements in this very salty water.
- 29:25SPEAKER_01: And this is where you can get mineable lithium coming out of it.
- 29:29SPEAKER_01: Now, this is an area of very active research and probably a great solution to the lithium demand in the future is that in order to mine lithium economically in this way with lithium brines, you basically have to have like really cheap land where you can spread out a lot of water very shallow and let it evaporate.
- 29:51SPEAKER_01: And there are places in the US, for instance, like the Salton Sea, where there's a lot of lithium-rich brine around, but the land's too expensive to just create an evaporation pond out of it.
- 30:00SPEAKER_01: Like we need a more efficient way to get lithium out.
- 30:02SPEAKER_01: And so there's a lot of developments both on where the lithium brine is coming from and how do we extract lithium.
- 30:09SPEAKER_01: There's a lot of lithium in various brines in different parts of the earth.
- 30:13SPEAKER_01: So we get brines out of like geothermal energy wells.
- 30:16SPEAKER_01: So if you pump a well down and you pump out hot water, that's a brine, really, and that can contain lithium.
- 30:22SPEAKER_01: It's lower concentration than the mineable brines, but if you can get it out more efficiently, uh, you can extract lithium.
- 30:28SPEAKER_01: It's a viable way.
- 30:29SPEAKER_00: Yeah, that makes a lot of sense.
- 30:30SPEAKER_00: If you can find an area that has rocks that have, you know, lithium in it, but it's dispersed, and then you circulate hot water through it, it's gonna selectively dissolve those kinds of metals, right?
- 30:42SPEAKER_00: And lithium is gonna be one of those metals that's gonna be dissolved.
- 30:45SPEAKER_00: And then so it circulates through vast volumes of this crustal rock.
- 30:49SPEAKER_00: Then we know that crustal rocks have higher concentrations of lithium, bring that water back up to the surface, separate the lithium out from the water, and there you go.
- 30:57SPEAKER_00: That's what we're talking about, right?
- 30:58SPEAKER_01: Yeah, that's exactly right.
- 30:59SPEAKER_01: So let's put some numbers to that.
- 31:01SPEAKER_01: We said that the lithium oxide content of things like spagyamine and lipidolite were like two to three percent at most.
- 31:08SPEAKER_01: The lithium content of these brines, they're about 200 to 2,000 parts per million.
- 31:12SPEAKER_01: So that's 0.02 or 0.2%.
- 31:15SPEAKER_01: So significantly lower concentrations of lithium, even in these high concentration brines, it's just way easier to get it out of a brine.
- 31:23SPEAKER_01: It's way cheaper to get it out of a brine.
- 31:25SPEAKER_00: And these are bigger than a typical pegmatite deposit, right?
- 31:31SPEAKER_00: Uh, you know, pegmatites tend to be rather small.
- 31:34SPEAKER_00: These kind of playa lakes.
- 31:36SPEAKER_00: Uh um, should we define what a playa is, Jesse?
- 31:39SPEAKER_00: Okay, so it's a playa lake is basically when you have think of a mountainous desert, hot, dry area, right?
- 31:46SPEAKER_00: As streams come out of the mountains and they enter these the flat desert plain, there's no direct avenue to the ocean.
- 31:53SPEAKER_00: So it just forms these like shallow, flat, very, very salty lakes, and the water then evaporates, leaving the salts behind, forming these like enriched mats.
- 32:04SPEAKER_00: So that's basically what a playa lake is.
- 32:05SPEAKER_01: So yeah, that's that's exactly what we're talking about.
- 32:08SPEAKER_01: So these new types of brines, so oil fields are also a place where we drill down into the earth, we have fluids coming out, there's a lot of water that comes out in an oil field, an active oil field.
- 32:19SPEAKER_01: Those things and geothermal energy systems where you're pumping hot water out of the ground, those brines have about 100 to 200 ppm concentration of lithium.
- 32:28SPEAKER_01: So a little bit, again, lower than brines, but again, if we can make the extraction economical, these things would be great.
- 32:34SPEAKER_01: And there's one other type, Chris, that's that's a really big deal in the US right now, at least, because there's a proposed mine that I think is going to happen in Thacker Pass, what's called Thacker Pass in the McDermott Caldera out in the western US.
- 32:48SPEAKER_01: And this is actually a sedimentary deposit.
- 32:50SPEAKER_01: So these are sedimentary rocks.
- 32:52SPEAKER_01: It's basically a former brine lake, a former playa lake.
- 32:55SPEAKER_01: Like this was an area where this big volcano erupted.
- 32:59SPEAKER_01: Huge caldera was formed, the McDermott caldera.
- 33:03SPEAKER_01: It's a 16.3 million year old supervolcano.
- 33:06SPEAKER_01: So the supervolcano blew up, uh, you know, made this caldera, think the Yellowstone caldera system, and then erosion happened and sort of made a lake in the middle of this caldera.
- 33:17SPEAKER_01: You can picture like crater lake or yellowstone lake to get a vision of the size of this lake.
- 33:22SPEAKER_01: And that was a restricted lake where all this water is flowing in.
- 33:26SPEAKER_01: It was just evaporating, and so lithium was concentrated in the sedimentary rocks at the base of that.
- 33:31SPEAKER_01: Now, the Stacker Pass mine would go and mine these sediments that have lithium in them.
- 33:37SPEAKER_01: So it's not actually directly extracting from the brine, it's extracting from the rock that represents the ancient brine, basically.
- 33:43SPEAKER_00: Well, right, but you also, when you were describing how you need this like hot, salty water, and you need also crustal rocks.
- 33:51SPEAKER_00: I thought of Yellowstone right away.
- 33:53SPEAKER_00: I mean, you'd think that that would be a really good place to have concentrated lithium, right?
- 34:00SPEAKER_00: Because you have the heat source, you have abundant water, you have fractured rocks, you're gonna have water that's this hot, salty water flowing through really enriched crustal rocks.
- 34:12SPEAKER_00: I mean, and that's that's really what you need.
- 34:14SPEAKER_00: And I think that like that's what's happening with Thacker Pass, right, Jesse?
- 34:17SPEAKER_00: That's the role of the volcano in this.
- 34:19SPEAKER_00: And I think that that's a new like we're just learning about this in terms of potential sources for lithium.
- 34:26SPEAKER_00: Is that right?
- 34:27SPEAKER_00: This is newer stuff.
- 34:28SPEAKER_01: That's exactly right.
- 34:29SPEAKER_01: And you know what we gotta do?
- 34:30SPEAKER_01: We gotta get some of these people who do this stuff on our podcast.
- 34:32SPEAKER_01: We gotta we gotta go talk to people who look at Thacker Pass, lithium, and we gotta talk to some of these people who develop these membranes to filter lithium.
- 34:40SPEAKER_01: Let's put that on that goal for the next uh next year here is to find some interesting people who know a lot more about lithium in these settings than we do.
- 34:47SPEAKER_01: That would be great.
- 34:48SPEAKER_00: Absolutely, but uh you know it's also important to note that this whole Thacker Pass is very, very controversial.
- 34:54SPEAKER_00: I first saw this on I think a 60 Minutes episode on Sunday night, because you have people that are camped out there and have been camped out there and haven't left Thacker Pass for a long time trying to block the mining of this place.
- 35:09SPEAKER_00: So it's really, really controversial.
- 35:10SPEAKER_01: And I think lithium is is a great example of this dynamic that we really need lithium if we want to generate the electric vehicles that we think will help fight climate change.
- 35:25SPEAKER_01: But in order to do that, we have to turn around and mine lithium somewhere.
- 35:29SPEAKER_01: And we have to do that sustainably as possible, but we have to do it.
- 35:33SPEAKER_01: And so the Thacker Pass thing is a very good example of you know, watch that space because it kind of represents all of the controversies all tied into one about how do we go forward in the future here with the energy transition and obtaining the raw materials we need for the energy transition that we kind of have to do.
- 35:53SPEAKER_00: So and I also think it highlights uh an important aspect to lithium too, which we haven't touched on in this episode, which is the recycling of lithium.
- 36:00SPEAKER_00: You know, that has to be a part of the solution too.
- 36:03SPEAKER_00: It can end up in landfills.
- 36:05SPEAKER_01: That's right.
- 36:06SPEAKER_01: That's right.
- 36:06SPEAKER_01: Recycling would be a huge, huge part of this as well.
- 36:09SPEAKER_01: So, Chris, I think that's probably enough for lithium, for the geology of lithium.
- 36:14SPEAKER_01: Do we cover all our bases here?
- 36:16SPEAKER_00: I think so.
- 36:17SPEAKER_00: Um, you know, we talked about why lithium is important, and we talked about the two main geologic settings where lithium is found concentrated and why it's concentrated there.
- 36:27SPEAKER_00: And then we ended up talking about maybe a new source to look for lithium in the future related to like supervolcanoes and crustal rocks.
- 36:35SPEAKER_01: And again, this is sort of a high-level summary where we're we're glossing over some of the interesting details, but we'll uh we'll get somebody who knows a little bit more to talk about those details because uh it's really interesting.
- 36:44SPEAKER_01: I'm super interested in this lithium.
- 36:46SPEAKER_01: I mean, some of these rocks that are erupted in some of these supervolcanoes, some of them they're small rock layers, but some lavas have like six percent lithium in them.
- 36:55SPEAKER_01: Like they're crazy lithium, like really weird magma compositions that have loads of lithium in them.
- 37:01SPEAKER_01: And uh they're they're sort of an anomaly, a curiosity, because they're not a large volume and not big enough to be mined that we know of yet, but they're really interesting scientifically as well, I think.
- 37:11SPEAKER_01: So anyway, Chris, cool.
- 37:13SPEAKER_01: That was good, man.
- 37:14SPEAKER_01: Fun.
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