Advanced thermal processing of used lithium batteries through controlled pyrolysis, also known as carbonization in the recycling industry, removes the electrolytes, the PVDF binder and the separator from the battery before the mechanical separation stage. A lithium battery recycling line by carbonization produces a dry calcined material, free of volatilized organic components, which separates mechanically much more efficiently and cleanly than non-pyrolyzed batteries.
A lithium battery recycling line by carbonization with a rotary or tunnel furnace is the choice of operators who prioritize black mass purity and clean separation over a simple shredder followed by non-optimized separation. The controlled thermal treatment prepares the material for subsequent hydrometallurgical extraction. See the full range of recycling equipment and the complete integration into the flow.
Key Advantages of Carbonization in Lithium Battery Recycling
• Electrolytes fully removed, carbonization evaporates and burns the electrolytes in the furnace, eliminating the risk of contaminating the black mass with organic residues.
• PVDF and separator removed, the polymer binder of the electrodes and the separator film decompose in the furnace, leaving the active material clean.
• More efficient mechanical separation, the dry calcined material separates much more efficiently by sieving and electrostatic separation than non-pyrolyzed batteries with residual polymers.
• Purer black mass, the purity of the black mass produced from pre-calcined material is superior to direct separation without thermal treatment.
• Pyrolysis gas treatment, the organic and acidic gases from the furnace are treated by secondary combustion, scrubber and activated-carbon filtration.
• N₂ protection at the initial breach, the first shredding stage under nitrogen eliminates the fire risk of residual electrolytes.
• PLC control of the thermal profile, the treatment temperature and duration adjust according to the chemistry of the battery being processed.
• Continuous or batch flow, depending on the configuration and the available volume.
Technical Specifications, Lithium Battery Recycling Line by Carbonization
| Parameter | Value |
|---|---|
| Thermal treatment type | Controlled pyrolysis / carbonization: rotary or tunnel furnace |
| Feedstock | Used lithium-ion batteries, various formats and chemistries |
| Preliminary stage | Shredding under N₂ (if the batteries are not pre-discharged) |
| Furnace | PLC-controlled thermal profile; inert or O₂-reduced atmosphere |
| Intermediate products | Dry calcined material, free of electrolytes, PVDF and separator |
| Post-calcination separation | Sieving, magnetic separator, electrostatic separator, crusher |
| Final products | Black mass (high purity), copper, aluminum, steel/Al casings |
| Gas treatment | Secondary combustion + scrubber + activated carbon |
| Capacity | Configurable per project |
Applications and Advantages of Thermal Treatment of Lithium Batteries
A lithium battery recycling line by carbonization is chosen by operators who supply black mass to hydrometallurgical refineries with strict composition specifications. The presence of PVDF residues or partially evaporated electrolytes in the black mass lowers the yield of the hydro process and can create problems in acid leaching; removing them through preliminary pyrolysis produces a more "hydro-friendly" and better-paid black mass.
Lithium-ion batteries are classified as hazardous waste due to the lithium hexafluorophosphate (LiPF₆) based electrolytes and organic solvents; a lithium battery recycling line by carbonization delivered in Europe is designed in accordance with the requirements of Regulation (EU) 2023/1542 on batteries. For complete integration, see also the complete industry solutions.
The carbonization process also solves the problem of the active material's cohesion at the electrode: in unburned batteries, the active material is bound to the metal foil by PVDF, a tough polymer. During carbonization, the PVDF decomposes thermally, completely releasing the active material from the foil. The separation of the black mass from the copper and aluminum foil in the mechanical stage is thus much more complete, with higher recovery yields.
The carbonization temperature is chosen according to the battery chemistry: LFP requires different parameters from NMC or LiCoO₂. A line with a PLC-controlled thermal profile allows the settings to be adjusted for each batch, a major advantage for operators who receive mixed batteries with different chemistries and must produce black mass of constant quality for several buyers.
Gas treatment is more demanding than for a simple shredding line, because the pyrolysis gases contain HF (from the decomposition of LiPF₆), volatile organic compounds and fine particles. The secondary combustion chamber oxidizes the organic compounds; the alkaline scrubber neutralizes the HF; the activated-carbon filters capture the residual traces; catalytic combustion finalizes the purification of the discharged gas. This sequence is mandatory for compliance with the European emission standards.
An operational advantage of carbonization is the reduction in the volume of material to be processed in the mechanical stage: the water, electrolytes and polymers volatilized in the furnace reduce the total mass by a significant percentage. The mechanical separation stage thus works with a drier, more uniform material with fewer contaminants, which means cleaner sieves, more efficient separators and reduced maintenance.
Comparison: With and Without Carbonization
| Criterion | Without carbonization | With carbonization (this line) |
|---|---|---|
| Black mass purity | Medium, possible PVDF residues | High, no PVDF and electrolytes |
| Separation yield | Lower, PVDF adhering to foil | Higher, PVDF thermally decomposed |
| Gas treatment | Simple | Complete (combustion, scrubber, activated carbon) |
| Operational complexity | Medium | Medium to high |
| Suitable for | Standard black mass | Premium black mass for refineries |
How It Works
1. The discharged batteries are fed onto the input conveyor and, if needed, pre-shredded under N₂.
2. The material enters the carbonization furnace with a controlled thermal profile; the electrolytes, PVDF and separator are volatilized.
3. The gases are treated through a secondary combustion chamber, an alkaline scrubber and activated carbon.
4. The cooled calcined material is sieved to separate the raw black mass.
5. The crusher releases the black mass from the remaining foil pieces; the magnetic separator extracts the steel.
6. The electrostatic separator or airflow separates the copper from the aluminum in the metal fraction.
The PLC system controls the furnace temperature profile, the gas flow and all the separation parameters. A well-tuned line produces black mass at constant specification, batch after batch, for delivery to refineries with documented requirements.
Frequently Asked Questions
What does carbonization of used lithium batteries mean in the recycling context?
Carbonization is the controlled thermal treatment (pyrolysis) that volatilizes the electrolytes, decomposes the PVDF binder and removes the separator from the battery, producing a dry, clean calcined material. The line separates the mechanical fractions from a pre-calcined material more efficiently and cleanly than batteries not treated thermally.
What black mass purity does it produce compared to a line without pyrolysis?
Black mass from pyrolysis has a significantly lower residual organic content (PVDF, electrolytes) than direct separation. This means a better yield in hydrometallurgical leaching and a better price at refineries. For NMC and NCA batteries with a high PVDF content, the purity difference is most visible.
What gases are produced and how are they treated?
The gases from carbonization contain HF (from LiPF₆), volatile organic compounds and CO₂. Complete treatment includes secondary combustion at high temperatures, an alkaline scrubber for HF neutralization, activated-carbon filters and catalytic combustion for residual traces.
Can a mix of battery chemistries be processed?
Yes, by adjusting the furnace thermal profile. Sorting by chemistry before carbonization produces black mass with a more homogeneous composition, easier to sell to refineries with strict specifications. For mixed batteries, the profile is chosen for the dominant chemistry in the batch.
Why URSTAG?
URSTAG is a premium brand of recycling equipment, with over 15 years of experience. You don't just get a machine, you get a solution engineered by specialists, built from top-tier components and backed by a team that supports you from design through commissioning.
• European engineering, every machine and every complete line is designed by our engineering teams in Europe, with a focus on reliability, safety and energy efficiency.
• Premium components, we build on motors and automation from industry leaders: Siemens, Schneider Electric, ABB, WEG, SEW-Eurodrive, NORD Drivesystems and Bonfiglioli.
• Over 15 years of experience, we know how materials and machines behave in real-world operation, and we configure each solution for your flow and volume.
• New equipment, configured for you, we supply new units, made to order for your application, with complete technical documentation.
• Delivery, installation and training included, we handle transport, commissioning and operator training, with support throughout the equipment's life.
As a premium brand, URSTAG relies on European engineering, top-tier components and experience. You choose a partner that supports your production long term, with equipment built to run reliably in demanding industrial environments.
