1. Two Sources, Two Processes
Lithium comes mainly from two sources. Brines, found in salt flats and deep underground reservoirs, are pumped to the surface and concentrated by evaporation. Hard-rock deposits, such as spodumene, are mined, crushed and processed into a concentrate before chemical conversion. Each route has a different cost, timescale and environmental footprint.
2. Why Evaporation Takes Time
Concentrating a dilute brine means removing large volumes of water, and water has a high latent heat of vaporisation, so the process needs either a lot of sunlight and surface area or a large energy input. Evaporation ponds in arid regions can take many months, and their rate depends heavily on weather, which is why the timescale is long and the output can vary from season to season.
3. Hard-Rock Processing
Hard-rock routes process ore into a concentrate, then convert it into a lithium compound through roasting and chemical steps. The thermal stages are energy-intensive, and the environmental footprint depends on the energy source and the handling of process residues. The route is faster to bring online than some brine projects, but it involves more mining and more energy per tonne of product.
Lithium routes compared (qualitative)
| Route | Typical time to output | Main energy demand | Main water concern |
|---|---|---|---|
| Brine evaporation | Months, weather dependent | Low direct energy, large land area | Water loss to evaporation |
| Hard-rock processing | Faster to start, mining required | High, mainly in thermal steps | Process water and residue management |
| Direct lithium extraction | Depends on the technology | Varies with the method | Varies, often lower net water use |
4. Direct Lithium Extraction
Direct lithium extraction (DLE) describes methods that remove lithium from brine more selectively, using adsorbents, ion exchange, membranes or solvent extraction, rather than relying on evaporation alone. These methods can shorten the process and may reduce land use. Their commercial performance is still being proven across different brines, so claims about any single method should be checked against project data.
5. Reading Project Claims
Project announcements often quote production targets without describing the water source, energy supply or recovery rate. When comparing projects, ask which route is used, how the energy is supplied, what the water balance is, and how much of the lithium in the source is recovered.