With the rapid expansion of the new energy vehicle industry, the demand for lithium-ion batteries continues to rise. Lithium iron phosphate (LFP) batteries, with their high safety, long cycle life, and stable performance, have secured an important position in electric vehicles and energy storage applications. However, natural lithium resources are limited, and the imbalance between supply and demand is becoming increasingly prominent. In this context, the resource recovery of spent lithium iron phosphate batteries is not only essential for environmental protection but also a critical measure to ensure the strategic security of lithium resources.

At present, although existing recycling technologies for spent LFP batteries can achieve preliminary separation of valuable metals, they generally face challenges such as unstable product purity, relatively low recovery efficiency, and complex process flows. Based on its CWL-M series centrifugal extractor, Zhengzhou Tiei Extraction provides an efficient, stable, and cost-effective process solution for LFP battery recycling, enabling high-purity closed-loop recovery of valuable elements such as lithium, iron, and phosphorus.

Innovative Process Route: Four-Stage System for Integrated Resource Recovery

This solution adopts a four-stage process route of pre-treatment – leaching – extraction purification – product preparation. By precisely controlling key parameters at each stage, efficient separation and high-value utilization of valuable metals are achieved.

1.Pre-treatment Activation
The cathode active powder from spent LFP batteries undergoes controlled calcination/aging treatment to disrupt its original crystal lattice structure, creating favorable conditions for subsequent efficient leaching. By optimizing temperature and residence time, lithium, iron, and phosphorus are converted into more leachable states, significantly improving the overall recovery efficiency.

2.Two-Stage Countercurrent Leaching
A multi-stage countercurrent leaching process is applied to achieve deep leaching of the activated material. By optimizing the liquid-to-solid ratio and leaching time, the concentrations of phosphate ions, ferrous ions, and lithium ions in the leachate reach an optimal balance, while minimizing co-leaching of impurity ions and laying the foundation for subsequent extraction purification.

3.Deep Impurity Removal by Centrifugal Extraction
This step is the core of the entire process. Copper impurities in the leachate are first removed via iron powder displacement, after which the solution enters the CWL-M centrifugal extraction system for deep aluminum removal. A mixed extractant system of di(2-ethylhexyl) phosphoric acid (D2EHPA) and sulfonated kerosene is used for selective aluminum extraction. Under a three-stage countercurrent extraction configuration and an optimized phase ratio of 1:1, efficient and selective separation of aluminum is achieved.

  • The CWL-M series centrifugal extractor demonstrates outstanding performance in this stage:
  • Enhanced mass transfer efficiency: Under a centrifugal field of 800–1200 G, the extractant and leachate are intensively mixed at the micron scale, reducing aluminum ion mass-transfer time to the second level.
  • High separation precision: Strong centrifugal force ensures rapid and clear phase separation, with extractant entrainment <0.1% and aluminum removal efficiency above 99.2%.
  • Optimized operating cost: Extractant recycling efficiency exceeds 98%, reducing solvent consumption by more than 35% compared with conventional mixer-settlers.
  • Compact equipment design: Each unit occupies only 2–3 m², and multi-stage series configuration enables continuous automated operation, reducing manual intervention by approximately 70%.

4.High-Purity Product Preparation
The purified solution undergoes sequential phosphate oxidation precipitation and carbonate lithium precipitation steps to produce battery-grade iron phosphate and lithium carbonate, respectively. Test results show that the purity of iron phosphate exceeds 99.5%, while lithium carbonate purity exceeds 99.7%. Impurity levels fully meet industry standards, allowing direct reuse in lithium iron phosphate cathode material production.

Industry Application Value

This process solution has been successfully implemented in multiple new energy recycling enterprises. In a lithium battery recycling project, after adopting the CWL-M-450 centrifugal extraction unit, the aluminum removal rate remained stable above 99%, while the purity of lithium carbonate increased from 98.2% to 99.6%, generating more than RMB 12 million in additional annual benefits. In another project, process upgrading improved the lithium recovery rate from 82% to 96%, while achieving fully automated operation in the extraction section and reducing labor costs by 65%.

With the approaching wave of retired power batteries, efficient recycling technologies will become a critical foundation for the sustainable development of the new energy industry chain. Zhengzhou Tiei Extraction will continue advancing centrifugal extraction technology to deliver more efficient and reliable solutions for closed-loop utilization of lithium resources.
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