How Is Lithium Extracted from Spodumene?

lithium mine

Lithium powers our modern world, from smartphones to electric vehicles (EVs). But before it reaches batteries, it’s locked inside minerals like spodumene, a lithium-rich ore found in hard rock deposits. Extracting lithium from spodumene is a complex but vital process. In this guide, we’ll down how spodumene is transformed into battery-grade lithium, step by step.

Spodumene (LiAlSi₂O₆) is a top source of lithium due to:

• High Lithium Content: Contains 6–7% lithium oxide (Li₂O), far richer than brine deposits.

• Fast Processing: Unlike brine evaporation (which takes months), spodumene can be processed in days.

• Purity: Yields high-grade lithium for premium batteries.

Spodumene ore

Step 1: Mining & Beneficiation

Before extraction begins, spodumene ore must be upgraded through beneficiation:

1). Crushing & Grinding:

Ore is blasted, crushed into gravel, then ground into a fine powder to liberate spodumene crystals.

2). Gravity Separation:

Heavy minerals like spodumene are separated from lighter waste using spirals or shaking tables.

3). Froth Flotation:

Chemicals: Collectors (e.g., fatty acids) make spodumene particles hydrophobic (water-repelling).

Air Bubbles: Carry spodumene to the surface as froth, while waste sinks.

Result: A spodumene concentrate with 5–7% Li₂O.

Lithium ore flotation-magnetic separation combined process principle flow chart

Step 2: Thermal Treatment (Calcination)

Raw spodumene is chemically stable and resistant to acids. To unlock lithium:

• Heating: The concentrate is roasted at 1,100°C in a kiln.

• Phase Change: Converts α-spodumene (stable) to β-spodumene (reactive), making it soluble in acid.

Step 3: Acid Leaching

The β-spodumene is mixed with sulfuric acid (H₂SO₄) to extract lithium:

• Acid Digestion:

Heated to 250°C, β-spodumene reacts with acid to form lithium sulfate (Li₂SO₄).

• Water Leaching:

The mixture is dissolved in water, creating a lithium sulfate solution.

Step 4: Purification & Precipitation

The lithium solution is cleaned to remove impurities:

• Neutralization:

(Ca(OH)₂) is added to precipitate metals like iron and aluminum.

• Filtration:

Impurities are filtered out, leaving a purified Li₂SO₄ solution.

• Carbonation:

Sodium carbonate (Na₂CO₃) is added to precipitate lithium carbonate (Li₂CO₃), a white powder used in batteries.

Alternative: Adding sodium hydroxide (NaOH) produces lithium hydroxide (LiOH), preferred for high-nickel EV batteries.

Step 5: Drying & Packaging

The lithium carbonate or hydroxide is:

• Dried: In rotary dryers to remove moisture.

• Packaged: Shipped to battery manufacturers for further refining.

Construction of spodumene processing plant

• Energy-Intensive: Calcination requires high heat, often from fossil fuels.

• Tailings: Waste rock from beneficiation must be stored in lined ponds.

• Acid Use: Sulfuric acid handling demands strict safety protocols.

• Direct Lithium Extraction (DLE): Emerging tech skips calcination by using solvents or membranes.

• Solar-Powered Kilns: Reduce carbon footprint of thermal treatment.

• Recycling: Reusing process water and acids to cut waste.

Flotation equipment in a spodumene processing plant in Zimbabwe

Q: Why not use lithium brine instead of spodumene?

A: Brine is cheaper but slower (12–18 months evaporation) and less pure. Spodumene meets booming EV battery demand faster.

Q: How much lithium is lost during processing?

A: Modern methods recover 80–90% of lithium from ore.

Q: Is spodumene mining sustainable?

A: While energy-heavy, new tech like DLE and renewables are making it greener.

Extracting lithium from spodumene is a blend of geology, chemistry, and engineering. By upgrading ore through beneficiation, unlocking lithium with heat and acid, and refining it into battery-grade products, miners power the clean energy revolution. As demand for EVs soars, innovations in efficiency and sustainability will ensure spodumene remains a cornerstone of the lithium supply chain.

Feel free to contact us and learn more about lithium processing solutions!