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into the future. Sequestering greenhouse gases can, in part, be Most lithium derives from minerals, making minerals the lynch-
achieved by chemical reactions with minerals for one effective pin for progress. Spodumene, LiAlSi O , is the most commonly
2
6
approach to carbon sequestration, that is, mineral trapping (e.g., mined and abundant mineral used for lithium extraction (Table 1,
Seifritz, 1990; Oelkers et al., 2008). Magnesium-rich minerals (e.g., Fig. 5; Bowell et al., 2020). Spodumene contains 3.7 weight percent
olivine, serpentine) react with carbon dioxide to form carbonate (wt%) Li per formula unit. Thus, 214 kg of pure spodumene are
minerals that sequester the carbon [e.g., serpentine + carbon diox- needed for a single car battery! Recently, spodumene was priced at
ide = magnesite + quartz + water; Mg Si O (OH) + CO = MgCO an all-time high of US$2240/tonne (from western Australia).
4
3
3
5
2
2
+SiO +H O]. Not only is this method geologically rapid—kinetics Worldwide estimates of lithium reserves suggest more than 62 Mt
2
2
from both the lab and the field suggest mineral trapping occurs in (Bowell et al., 2020). As IEA notes, this massive industrial conver-
about two years (Matter et al., 2016)—it results in more permanent sion marks a “shift from a fuel-intensive to a material-intensive
storage for carbon than for other geologic mechanisms of trapping energy system” (IEA, 2021). Minerals are the key—they are the
(e.g., Oelkers et al., 2008). According to the International Energy reservoirs for our technological future.
Agency (IEA, 2021), there are ~20 commercial carbon-capture,
utilization, and storage facilities worldwide, with 30 more planned. Table 1. Major minerals from which lithium is extracted
Earth scientists with an understanding of mineralogy and mineral- Minerals* Li O Chemical formula
2
fluid interactions are essential for this 4-billion-dollar industry. (wt%)
Spodumene # 6–9 LiAlSi O
2 6
Critical “Minerals” Petalite 4.71 LiAlSi O 10
4
Across the spectrum of renewable “clean” energy technologies, Lepidolite 4.19 KLi Al(Si O )(F,OH) to
2
4
10
2
elements obtained largely through the mining of particular minerals, (series polylithionite-trithionite) KLi Al (Si AlO )(F,OH) 2
3
1.5
1.5
10
and less commonly the minerals themselves, are critical for imple- Amblygonite–Montebrasite 7.4 LiAlPO F to LiAlPO (OH)
4
4
mentation. Topping IEA’s list of overall critical elements are copper, Eucryptite 9.7 LiAlSiO 4
nickel, chromium, and zinc, along with rare earth elements (REEs), Triphylite 9.47 LiFe PO 4
2+
cobalt and lithium for battery storage, and aluminum for electricity *Data from Bowell et al. (2020).
networks (IEA, 2021). While the absolute amount varies depending # 8 kg Li = 214 kg spodumene.
on the energy system, stated governmental policy goals, future plan-
ning scenarios, and technological advancements, the ability to secure
mineral commodities is the fulcrum in achieving the energy transi-
tion away from fossil fuels. This need is crucial for electric vehicle
(EV) and battery technologies. REEs, essential in the manufacture of
hybrid and electric cars, high-strength magnets for wind turbines,
and solar energy panels, are housed in unusual minerals or adsorbed
onto their surfaces. The demand for REEs continues to outstrip sup-
ply, a situation likely to continue unabated even as new sources are
discovered (e.g., monazite sands; Network NewsWire, 2021).
Knowledge of mineralogy and mineral systems is needed to locate
new resources as demand increases, and to mine, extract, and manu-
facture materials and their byproducts in responsible ways to mini-
mize environmental damage and human-health impacts.
The global clean energy transitions will have far-reaching conse-
quences for mineral demand over at least the next 20 years. IEA
predicts that by 2040, total mineral demand from clean energy
technologies will double in some scenarios and quadruple in others Figure 5. Spodumene, a primary source of lithium. (A) Specimen 28 × 15.6 ×
2.2 cm. Big Kahuna II zone, Oceanview Mine, Pala District, San Diego
(IEA, 2021). EV and battery storage account for about half of the County, California, USA. Oceanview Mines, LLC, specimen (20120615–01);
mineral demand growth, largely for battery materials (lithium, (B) spodumene in the rock. © Mark Mauthner photos, used with permission.
graphite, cobalt, nickel, manganese). To support this increasing
technological demand, mineral requirements will grow tenfold to Minerals as Templates
over 30 times over the period to 2040. By weight, graphite, copper, Minerals can act as functional templates for advanced materials
and nickel dominate. The need for lithium has the fastest growth underlying renewable energy systems. “Wide ranges of additional
rate, predicted to be more than 40 times current requirements, minerals are used and will be used as the energy landscape is
although new battery technologies may dampen some of this transformed to more renewable, cleaner energies” (Saucier, 2021).
demand (IEA, 2021). Geoscientists with an understanding of minerals, their structures,
Current battery technology alone will have significant implica- and compositions, are the “backbone” of the energy transition
tions for specific elements. A single lithium-ion EV battery pack (Saucier, 2021). Earth scientists are familiar with the perovskite
(CNM532) contains ~8 kg of lithium, 35 kg of nickel, 20 kg of man- group of minerals. The magnesium-silicate perovskite species,
ganese, and 14 kg of cobalt (Castelvecchi, 2021). With the prediction bridgmanite (MgSiO ), comprises ~70% of Earth’s lower mantle
3
that in ~15 years 50% of the global passenger fleet will be electric (Tschauner et al., 2014), which is ~38% of Earth’s total volume.
(IEA, 2021), hundreds of millions of vehicles will carry batteries that Volumetrically, it is the most abundant mineral in planet Earth. Its
require immense quantities of these of critical materials. flexible crystal structure allows for a wide range of possible
14 GSA TODAY | February 2022