Integrating flotation and pyrometallurgy for recovering graphite and valuable metals from battery scrap

Ronja Ruismäki, Tommi Rinne, Anna Dańczak, Pekka Taskinen, Rodrigo Serna-Guerrero, Ari Jokilaakso*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

42 Citations (Scopus)
219 Downloads (Pure)


Since the current volumes of collected end-of-life lithium ion batteries (LIBs) are low, one option to increase the feasibility of their recycling is to feed them to existing metals production processes. This work presents a novel approach to integrate froth flotation as a mechanical treatment to optimize the recovery of valuable metals from LIB scrap and minimize their loss in the nickel slag cleaning process. Additionally, the conventional reducing agent in slag cleaning, namely coke, is replaced with graphite contained in the LIB waste flotation products. Using proper conditioning procedures, froth flotation was able to recover up to 81.3% Co in active materials from a Cu-Al rich feed stream. A selected froth product was used as feed for nickel slag cleaning process, and the recovery of metals from a slag (80%)–froth fraction (20%) mixture was investigated in an inert atmosphere at 1350 °C and 1400 °C at varying reduction times. The experimental conditions in combination with the graphite allowed for a very rapid reduction. After 5 min reduction time, the valuable metals Co, Ni, and Cu were found to be distributed to the iron rich metal alloy, while the remaining fraction of Mn and Al present in the froth fraction was deported in the slag.

Original languageEnglish
Article number680
Number of pages22
Issue number5
Publication statusPublished - May 2020
MoE publication typeA1 Journal article-refereed


  • Circular economy
  • Cobalt
  • Lithium-ion battery
  • Manganese
  • Mechanical treatment
  • Nickel
  • Recycling
  • Slag cleaning


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