Understand lithium mining's environmental impact

Published on

March 8, 2024

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By

Ara Persson

Commodities

Demand for lithium-ion batteries continues to surge, driven by the rise of electric vehicles (EVs), smartphones, and renewable energy storage solutions. Understanding the environmental impact of lithium mining has therefore never been more critical.

CarbonChain's analysis shows that the greenhouse gas (GHG) emissions associated with lithium carbonate — a key ingredient in these batteries — can reach up to 18 tonnes of carbon dioxide equivalent per tonne (tCO2e/t). This figure significantly fluctuates depending on the mining location, the energy sources used, and the extraction and processing techniques employed, highlighting the complexity of lithium's environmental footprint.

GHG emissions, however, represent only part of the environmental challenges surrounding lithium mining. The industry faces critical scrutiny over the management and disposal of chemicals throughout the production process, excessive water usage and the potential for habitat disruption.

What is lithium and why is it mined?

Lithium has become indispensable in the era of renewable energy and portable electronics, primarily due to its use in lithium-ion batteries which are essential for battery storage solutions, smartphones, laptops and EVs. The demand for lithium has surged as a result, prompting increased mining activities in countries like Australia, Chile, China and Argentina.

Lithium products can be mined from hard rock (spodumene) or extracted from brine reservoirs which contain a mixture of water and dissolved lithium salts. Lithium brine extraction is generally regarded as both more cost-effective and less environmentally harmful than traditional mining methods, but is said to be of lower 'quality' yield than hard rock mining.

Although lithium metal has its uses as a lightweight material, lithium carbonate and lithium hydroxide are the most common lithium products that are extracted from brine and hard rock mining, and that are used as inputs into EV batteries, and other key industries.

The lithium process and its environmental impact

Brine extraction and its environmental impacts:

• Acquisition Method: Involves pumping lithium-rich brine from underground aquifers into evaporation ponds.
• Concentration Process: The brine is evaporated in stages to remove impurities, with efforts made to recycle water where possible.
• Lithium Extraction: Chemical processes, including the use of hydrochloric acid and sodium carbonate, are employed to extract lithium from the concentrated brine, to produce lithium carbonate and lithium hydroxide.

The brine extraction method is notable for its high water consumption and the ecological disruption caused by evaporation ponds and drilling operations. Furthermore, the chemical use in the extraction process and the extensive land required for evaporation ponds contribute to its environmental footprint.

Lithium mining and its environmental impacts:

• Acquisition Method: This method involves extracting lithium-bearing minerals from ore through drilling, blasting, and crushing.
• Concentration and Roasting: The ore undergoes processes to concentrate the lithium, which is then roasted for further processing.
• Lithium Extraction: Lithium carbonate and lithium hydroxide are refined from the concentrated ore using chemical processes.

Hard rock mining can cause significant land disruption, waste generation in the form of tailings, and considerable energy use, all contributing to the overall environmental impact of lithium production.

Comparing the environmental impacts of lithium production from mining versus brine extraction

Carbon emissions of lithium produced through mining versus brine extraction ‍

CarbonChain’s analysis of global lithium emissions shows that lithium produced through mining is on average around three times more carbon intensive than lithium produced through brine extraction.

In the production of lithium through mining, the mining of spodumene contributes 15% of those emissions while downstream processing of lithium contributes 85% (excluding freight).

At the mine site, there is significant use of diesel as both an automotive fuel and fuel for onsite electricity generation. Therefore, technological efficiencies and transitioning to less carbon-intensive fuels are key ways to reduce emissions.

Is lithium mining worse than coal mining for the environment?

While lithium mining is more resource-intensive per unit than coal mining, the comparison is complex.

• If we compare the mining process alone, then coal mining and lithium mining have similar carbon footprints. Note: this comparison is between mining coal (product = coal) and mining hard-rock spodumene (product = a concentrate from which lithium is then extracted).

• Yet, coal then goes on to be used as a fuel, with a direct release of carbon emissions from combustion, while hard-rock concentrates go on to be refined into lithium products. This refining process results in additional carbon emissions; yet the use of lithium in products like EVs may result in carbon savings across the full life cycle of the lithium, compared to that of coal.

In short, although the direct mining carbon emissions are similar, the two products (lithium and coal) have different use cases, and cannot be meaningfully compared beyond mining.

Managing lithium’s environmental impact with CarbonChain

CarbonChain provides comprehensive data on lithium production emissions across over 40 mines and brine lakes in more than a dozen countries. Manufacturers and commodity traders use our software daily to satisfy carbon reporting requests and identify pathways to lower-emission lithium products.