Lithium sits at the centre of the energy transition, yet the way it reaches battery-grade form depends almost entirely on where it comes from. Most of the world's lithium is recovered from two very different sources: hard-rock spodumene deposits and saline brine lakes. The two routes share a goal — producing lithium chemicals — but the mining, the equipment, the timeframes and the cost profiles could hardly be more different. Understanding those differences is essential before anyone invests in lithium ore extraction equipment.
Why the source changes everything
Spodumene is a lithium aluminosilicate mineral found in granitic pegmatites. Chemically reactive lithium is locked inside hard rock, which means the deposit must be blasted, dug and hauled before any chemistry can begin. Brine, in contrast, is liquid: lithium ions are already dissolved as lithium chloride in underground saline aquifers beneath salt flats, and the first step is simply pumping that water to the surface. Brine avoids the energy-intensive blasting and crushing of hard rock, but it pays for that advantage in time — natural solar evaporation works on a scale of many months, not hours.
How spodumene is processed
Hard-rock processing is a physical-mechanical path first, and a chemical one second. Run-of-mine ore is crushed in a staged crushing circuit, then ground in a ball mill so the lithium mineral is liberated from quartz and feldspar gangue. The crushed pulp is fed to flotation, where reagents separate the spodumene from waste rock to produce a lithium concentrate. This concentration step is precisely where a dedicated concentrating plant earns its value — it lifts a low-grade ore into a saleable, transportable concentrate.
The concentrate is not yet battery-ready. Alpha-spodumene is a refractory mineral that resists chemical attack, so it must be roasted at roughly 1050–1100 °C in a rotary kiln to convert it to the reactive beta form, a step called decrepitation. From there an acid roast with sulphuric acid at 250–300 °C, or an alkaline limestone roast, liberates the lithium into a water-soluble liquor that is finally purified and precipitated into lithium carbonate or lithium hydroxide.
How brine is processed
Brine processing takes a totally different route. Lithium-bearing brine is pumped from deep aquifers into a series of shallow evaporation ponds, where the sun and wind slowly concentrate the lithium while sodium, potassium, calcium and magnesium salts crystallise out at different stages. Over a typical 12 to 24 months the brine concentrates enough to become a lithium-rich liquor, which is then purified and treated with sodium carbonate to precipitate lithium carbonate crystals.
The dominant impurity in most brines is magnesium. A high magnesium-to-lithium ratio complicates purification and can drag final purity below battery grade, so high-Mg/Li brines often need extra solvent-extraction or selective-precipitation stages. In short, brine is cheap to get to the surface but expensive in patience and purification chemistry.
The key differences at a glance
| Criterion | Spodumene (hard rock) | Brine |
|---|---|---|
| Raw state | Solid mineral in rock | Liquid dissolved in groundwater |
| First recovery step | Blasting, crushing, grinding, flotation | Pumping into evaporation ponds |
| Typical timeframe for a finished product | Months; concentrate ready quickly after the kiln is fired | 12–24 months of evaporation |
| Energy and capital | Higher energy, more equipment, faster ramp-up | Lower energy per tonne of lithium, slower to start |
| Geography | Australia, Canada, Zimbabwe, China | Chile, Argentina, Bolivia (Lithium Triangle) |
| Main technical challenge | Thermal decrepitation and recovery rate | Magnesium removal and purity |
The practical takeaway is that spodumene projects are faster to bring online and more predictable, while brine operations generally enjoy lower cash costs per tonne of lithium carbonate equivalent but need more patience and carry a heavier water and permit footprint.
Why the concentrating step matters so much
Between the mine and the refinery sits a stage many projects underestimate: concentrating. A run-of-mine spodumene ore may carry only a few percent lithium oxide, and it is the concentrating plant that upgrades it into a high-grade lithium concentrate. This is the part of the flowsheet where recovery efficiency, tailings grade and final concentrate purity are decided — and where well-designed machinery makes the difference between a profitable operation and one that leaks value at every stage.
San Lan Technologies builds this exact equipment. Its lithium crude ore processing plant converts raw lithium ore into lithium concentrate, with plants sized from 500 to 5000 tonnes per day and a design that pulls the final tailings grade down from the typical 0.25–0.3% level to around 0.15%. For operators who already hold old tailings, the lithium tailing ore extraction plant re-processes residue left by an original extraction line, lifting total recovery to about 75% against an industry average near 65%.
Choosing the right path
The choice between spodumene and brine is rarely made on price alone. It is driven by the project's geology, its location, water availability, access to reagents and how quickly the operator needs first concentrate. Hard-rock spodumene continues to dominate new supply because it is faster and geographically flexible, while brine retains an edge in low-cost, arid salt-flat regions. Whichever route a project follows, the upstream concentrating and extraction stage is where the equipment decision shapes the economics — and specifing the right processing plant from the outset repays the investment for decades to come.
