News

Reactive milling for the production of metallic black mass (MBM)

16/03/2023

Focusing on mechanochemical (MC) processing, the chemical transformation of the black masses (BMs) supplied by partners ACCUREC and TES, is planned to be carried out within Work package 4. 

Before MC processing, the black masses were analysed using a combination of different analytical techniques. Both quantitative and qualitative analysis were undertaken to determine the Lithium and transition metals yield of the developing recycling process. 

Using different reducing agents such as Al, Ca, and their mixtures, researchers carried out preliminary investigations of the MC processing of BMs. Within this task, different aspects, such as the role of the ball milling conditions, the ball milling time, presence of other nonreactive components, and nature of the reducing material were investigated. The analysis led to the conclusion that the kinetics of the MC-induced reduction reaction is sensitive to multiple processing parameters, as shown in the featured image: 

XRD patterns of the as-received BMs and products of their reduction after MC processing with Al and Ca as reducing agents

XRD patterns of the as-received BMs and products of their reduction after MC processing with Al and Ca as reducing agents: left-TES material; right-ACC material

The upcoming research will focus on improving the reduction reaction kinetics and eliminating the possible safety hazards of fine powder materials. Once finalised, this work will determine the optimal ball milling conditions to be scaled up. 

Recovery of Lithium as battery grade materials

The process described in Task 4.4 leads to the chemical transformation of the black masses (BMs) into ferromagnetic Co-, Ni- and Mn-containing products, which will be separated from other by-products. Lithium will be extracted from the rest of the solid products in the subsequent aqueous leaching process to be further transformed into battery-grade lithium carbonate (Li2CO3) salt. 

Within the M1-M6 period, aqueous leaching of the ball-milled samples using Al and Ca as reducing agents (RA) was carried out. At a preliminary stage of investigations, researchers noticed the resulted Li2CO3 materials presented small amount of impurities. 

To increase the yield of lithium recycling, in the upcoming period, the research work will target the improvement of the leaching conditions and the purification process.  

X-ray diffraction patterns of the as-milled black mass

X-ray diffraction patterns of the as-milled BM obtained from TES, products of their reduction reactions after MC processing with Al (left) and Ca (right) as RA, and obtained Li salts after aqueous leaching