Scaling up the separation of electrode active material from lithium-ion battery waste: Flotation cell scale-up and design, fabrication, and tests

초록

In this study, flotation was used as the separation and recovery process applied to black mass (BM) from lithium-ion battery (LIB) waste. Starting with the design of a 4-L Denver-type flotation cell (13.5 ×14.1 ×16 cm) as the model, a 25-L prototype cell (27.0 ×28.2 ×32.0 cm) was fabricated after a scale-up and design procedure that relied on multiphase simulations to predict the recovery by entrainment. The purpose of predicting the recovery by entrainment was to generate a scaled-up flotation cell with a newly designed impeller and stator that reduced the entrainment of lithium transition-metal oxides in graphite concentrates. Flotation tests with the new impeller-stator pair design resulted in a 98.0 ± 0.3% recovery and 81.1 ± 4.3% grade of graphite in a 2nd cleaner float and 70.9 ± 6.7% recovery and 98.3 ± 0.1% grade of lithium transition-metal oxides in a 2nd scavenger sink. Conversely, a cell scaled-up through only geometric similarity to retain the original impeller-stator pair design exhibited a 98.1 ± 0.1% recovery and 78.6 ± 0.8% grade of graphite in a 2nd cleaner float and 63.3 ± 0.1% recovery and 98.8 ± 0.1% grade of lithium transition-metal oxides in a 2nd scavenger sink. Therefore, the new design increased the grade by 2.5–3.9% with minimal variation in the recovery, indicating its efficacy by controlling entrainment.

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