Overview
The booming electric vehicle and energy storage industries have created a rapidly growing volume of spent lithium-ion batteries globally. Safe elimination of flammable organic components is an essential pretreatment step ahead of hydrometallurgical leaching. The continuous rotary pyrolysis carbonization kiln is specially developed for shredded battery scraps and black mass. It achieves stable organic decomposition, self-sustaining energy circulation and standardized tail gas treatment. As a core processing unit for modular lithium battery recycling plants, it supports customizable annual processing capacity ranging from 500 tons to 10,000 tons.
Feedstock & Performance Indicators
Processable materials:
- Spent NCM ternary lithium batteries, LFP lithium iron phosphate batteries, LCO lithium cobalt oxide batteries
- Input forms: crushed black mass, cell fragments from dismantled battery modules and packs
- Organic components: PVDF binder (3–5%), residual electrolyte, polyolefin separators
Core performance targets:
- Organic removal rate ≥98%
- Valuable metal recovery rate in subsequent leaching process >95%
- Recovered pyrolysis gas (H₂, CH₄, CO, etc.) for internal heating supply
- Tail gas emission: meets GB 16297 Integrated Emission Standard of Air Pollutants
- Customizable annual throughput: 500 tons – 10,000 tons
Process Principle
The system realizes oxygen-free pyrolysis and controlled carbonization under nitrogen or argon inert shielding atmosphere. Raw materials move forward inside the rotary cylinder at 500–800°C. Organic binders, residual electrolyte and separators undergo thermal cracking without open combustion. Three material streams are generated after reaction:
- Solid product: de-fluorinated carbonized material enriched with Ni, Co, Mn and Li metal oxides, ready for downstream leaching
- Gaseous product: combustible pyrolysis syngas, recycled as fuel to cut external energy consumption
- Liquid by-product: trace tar collected by condensation
Hazardous acidic gases including HF and POF₃ are captured by dedicated wet scrubbing units to prevent secondary pollution.
Complete Process Flow
Battery Pretreatment → Discharge → Dismantling → Shredding → Copper-aluminum separation → Black mass → Explosion-proof feeding system (nitrogen-purged screw feeder) → Main reaction zone: rotary pyrolysis carbonization kiln (500–800°C, inert atmosphere, residence time 30–60 min) → Water-cooled discharging system, cooled below 80°C → buffer silo → Flue gas purification line: primary cyclone dust removal → secondary baghouse fine dust removal → quenching tower → NaOH & Ca(OH)₂ acid-alkali scrubber → RTO/RCO thermal oxidation → stack discharge → Energy recovery loop: purified pyrolysis gas delivered to combustion chamber for self-heating
Main Technical Specifications of Rotary Pyrolysis Kiln (Reference Model: HG-Φ1200×14000)
- Structure: horizontal inclined rotary cylinder furnace, inclination angle 2–3°
- Effective cylinder dimension: Φ1200 mm × 18000 mm
- Inner liner: 310S high-temperature resistant stainless steel, thickness 12 mm
- Outer shell: Q345R carbon steel + multi-layer ceramic fiber insulation (total thickness ≥300 mm), stainless steel protective cladding
- Operating temperature: 500–800°C, maximum working temperature 900°C
- Heating options: indirect heating by symmetric dual gas burners; electric heating available for small-scale lines
- Maximum flame temperature: 1200°C (indirect heating, no direct contact between flame and materials)
- Rotation speed: VFD adjustable, 0.5–3 rpm stepless speed regulation
- Atmosphere control: continuous nitrogen protection, oxygen content ≤2%
- Sealing structure: labyrinth + graphite combined sealing at both ends to reduce air leakage
- Driving assembly: reduction motor, gear transmission and supporting rollers
- Scalable designs: Φ1.2m×12m, Φ1.5m×15m and other large-size configurations are available
Supporting Subsystems
- Explosion-proof continuous feeding system Equipped with double pneumatic gate valves and nitrogen-blanketed screw conveyor. The inert gas barrier blocks air ingress to eliminate explosion risks. Constructed from 304 stainless steel with IP65 protection grade. Feeding rate is adjustable to match pyrolysis reaction speed.
- Discharge and cooling system Water-cooled star discharger or cooling drum matched with bucket elevator. Circulating cooling water reduces solid product temperature below 80°C for safe storage. Fully sealed design prevents dust escape.
- Tail gas purification and online monitoring system
- Cyclone separator: remove coarse particles larger than 10 μm
- Bag filter: fine dust removal efficiency >99.5%, outlet dust concentration <30 mg/m³
- Quench tower: rapid cooling below 200°C to suppress dioxin formation
- Acid and alkali scrubbing towers: stepwise removal of HF, HCl and other acidic pollutants
- RTO/RCO unit: decompose residual VOCs and light hydrocarbons
- Continuous emission monitoring: real-time detection of O₂, CO, NOₓ and particulate matter, compatible with environmental supervision platforms
Key Advantages of This Rotary Pyrolysis Kiln for LIB Recycling
✅ Broad feed adaptability: suitable for NCM, LFP, LCO, mixed black mass and dismantled cell scraps ✅ Inert atmosphere design: stable pyrolysis reaction and low oxidation loss of valuable metals ✅ Self-sufficient energy recovery: syngas reuse greatly reduces fuel and power input ✅ Heavy-duty high-temperature construction: 310S liner and thick insulation extend service life ✅ Complete flue gas treatment package: targeted removal of fluorine-containing and acidic gas for stable compliance ✅ Flexible capacity layout: pilot and commercial-scale units support full EPC recycling projects
