[SMM Science Popularization] Brief Introduction to the Wet Process Production Flow of Ternary Lithium Battery Powder

Overview of Production Process Flow:

1. Feeding/Slurrying: The cathode and anode powder from waste ternary lithium batteries are pretreated and lifted to the slurrying tank by a crane. The powder is mixed with pure water in a semi-enclosed slurrying tank at a ratio not exceeding 2:1 and stirred. The slurry then enters the acid dissolution process. This step generates a small amount of feeding dust (G2-1).

2. Acid Leaching and Pressure Filtration Washing: Ternary powder with low aluminum content is transported to the dissolution kettle under negative pressure and treated with 98% sulphuric acid and hydrogen peroxide to dissolve metals and convert them into divalent metal ions. The acid solution is pressure-filtered, and the filter cake is washed with pure water to obtain crude graphite powder, while the filtrate proceeds to the next process. The main chemical conversion rate is 99%. This step generates acid leaching exhaust gas (G2-2) and acid leaching residue (S2-1).

3. Copper Extraction: The acid-leached solution containing 4–4.5 g/L of copper undergoes two-stage countercurrent extraction using 984H extractant, achieving a copper extraction rate of approximately 95%. The solution after extraction is used to recover copper sulphate through electrodeposition, generating exhaust gas (G2-3).

4. Copper Electrodeposition: Under the action of direct current, insoluble anode plates are used to deposit copper from the electrodeposition solution. Copper products are removed from the cathode every 7 days, washed, and packaged. The treated washing water is recycled for use in other sections, and the oxygen bubbles generated are discharged through system design to prevent acid mist emissions.

5. Copper Removal: The solution is heated with steam to remove copper, and the resulting copper slag is disposed of as solid waste. The copper removal efficiency is approximately 99%, generating exhaust gas (G2-4).

6. Iron and Aluminum Removal, Pressure Filtration Washing: Sodium chlorate is used to oxidize divalent iron, and sodium carbonate is used to precipitate iron and aluminum impurities. After pressure filtration and washing, the metal elements in the iron and aluminum slag are recovered, and the final slag is treated as solid waste. The iron removal efficiency is approximately 99.3%.

7. Calcium Removal Purification: Calcium impurities are removed using sodium carbonate, and the resulting calcium carbonate is disposed of as solid waste. The calcium removal efficiency is 95%.

8. Manganese Extraction with P204: Manganese is extracted using P204 extractant through a multi-stage continuous extraction process to improve efficiency (manganese extraction rate is approximately 85%). After oil removal, the stripped solution is treated and reused, generating exhaust gas (G2-5).

9. Cobalt Extraction with P507: Similarly, cobalt is extracted using a saponified extraction method, achieving a cobalt extraction rate of 99.5%. The organic phase is stripped with sulphuric acid and reused, generating exhaust gas (G2-7).

10. Cobalt Electrodeposition: During electrodeposition, cobalt is deposited on the cathode, washed, and packaged to obtain the product. The system design prevents acid mist emissions, ensuring high recovery rates.

11. Magnesium Removal with C272 Extraction: Magnesium is removed using saponified C272 extractant, and the resulting waste liquid and exhaust gas are treated and reused.

12. Nickel Extraction with P204: Crude nickel sulphate solution is extracted using P204 extractant (nickel extraction rate is approximately 99.5%), and the liquid proceeds to the lithium recovery section.

13. Nickel Electrodeposition: Nickel is deposited on the cathode through electrodeposition technology, with one batch processed every 14 days. The recovery liquid is recycled, and acid mist emissions are avoided, meeting environmental protection standards.

14. Lithium Recovery (MVR Evaporation and Lithium Precipitation): Lithium carbonate obtained through sublimation and evaporation is filtered, washed, dried, and finally packaged as a product.

15. Sodium Sulphate Airflow Drying: Wet sodium sulphate is processed using drying technology to obtain the by-product anhydrous sodium sulphate.

SMM New Energy Research Team

Cong Wang 021-51666838

Lingying Zhang 021-51666775

Xiaodan Yu 021-20707870

Rui Ma 021-51595780

Ying Xu 021-51666707

Disheng Feng 021-51666714

Yujun Liu 021-20707895

Yanlin Lü 021-20707875

Xianjue Sun 021-51666757

Chensi Lin 021-51666836

Zhicheng Zhou 021-51666711

He Zhang 021-20707850