Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment

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Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2022-01

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Mcode

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Language

en

Pages

18

Series

Minerals, Volume 12, issue 1

Abstract

The comminution of spent lithium-ion batteries (LIBs) produces a powder containing the active cell components, commonly referred to as “black mass.” Recently, froth flotation has been proposed to treat the fine fraction of black mass (<100 µm) as a method to separate anodic graphite particles from cathodic lithium metal oxides (LMOs). So far, pyrolysis has been considered as an effective treatment to remove organic binders in the black mass in preparation for flotation separation. In this work, the flotation performance of a pyrolyzed black mass obtained from an industrial recycling plant was improved by adding a pre-treatment step consisting of mechanical attrition with and without kerosene addition. The LMO recovery in the underflow product increased from 70% to 85% and the graphite recovery remained similar, around 86% recovery in the overflow product. To understand the flotation behavior, the spent black mass from pyrolyzed LIBs was compared to a model black mass, comprising fully liberated LMOs and graphite particles. In addition, ultrafine hydrophilic particles were added to the flotation feed as an entrainment tracer, showing that the LMO recovery in overflow products is a combination of entrainment and true flotation mechanisms. This study highlights that adding kerosene during attrition enhances the emulsification of kerosene, simultaneously increasing its (partial) spread on the LMOs, graphite, and residual binder, with a subsequent reduction in selectivity.

Description

Funding Information: This research was funded by the Helmholtz-Institut Freiberg f?r Ressourcentechnologienfor base funding within the PoF III (project oriented funding part III) for the BooMeRang project. The authors would like to thank Christoph Frey from ProGraphite GmbH for the graphite samples, Accurec GmbH for the spent black mass, and Daniel Bien from ExxonMobil for the reagent ESCAID 110. We would like to thank UVR FIA GmbH for the XRF analysis and the helpful discussions; Simon Obando Sierra, David Guzm?n Gallo, and Alvaro Jos? Rodr?guez Medina for their help with the flotation tests; and Thomas Heinig for guidance on the SEM image processing. Funding Information: Funding: This research was funded by the Helmholtz-Institut Freiberg für Ressourcentechnologienfor base funding within the PoF III (project oriented funding part III) for the BooMeRang project. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords

Black mass, Froth flotation, Graphite, Lithium metal oxides, Mineral processing, Recycling, Spent lithium-ion batteries

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Citation

Vanderbruggen, A, Salces, A, Ferreira, A, Rudolph, M & Serna-Guerrero, R 2022, ' Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment ', Minerals, vol. 12, no. 1, 72 . https://doi.org/10.3390/min12010072