A Combined Pyro- and Hydrometallurgical Approach to Recycle Pyrolyzed Lithium-Ion Battery Black Mass Part 1: Production of Lithium Concentrates in an Electric Arc Furnace

Round 1

Reviewer 1 Report

This manuscrip reports a nice study concerning recycling processes to extract valuable materials from Li-ion battery waste. The originality of the research is good and results support the conclusions.

I have some remarks to improve the quality of the manuscript.

1) uncertainties are required on data reported in tables 1, 3 (loss %), 4 and 5.

2) Please update the page composition of the manuscript: there are too many voids and empty sections on several pages;

3) the materials losses during the process is a key point: comparison with the literature is necessary to extablish similarities and differences. Plase update.

4) the origin of the materials losses in unsupported either by evidences or by reference literature. please update

5) in the thermodynamic modeling various databases have been used. However the reference literature is missing: please update

Author Response

Thank you very much for your time and your suggestions, here are my comments on your remarks and most of them are now considered in the paper:

1. Standard deviation of the measurements was added to table 1. The uncertainties of the weighed components are already included in the table by the significant digits for the values. The uncertainties of the weight losses are not predictable, I already quantified the losses due to taken slag samples and I tried to further explain, what the reason for mass losses could be. The standard deviations of the analysis from table 4 are now added to the supplementary material, it is not included in the main paper, as it would make table 4 unnecessarily long. For table 5, the mean value was replaced by the max. and min. value of the components.

2. I agree, in the first version, pictures etc. weren’t adjusted completely yet. Because of the review the paper had to be adjusted and the layout would change. So I tried to improve the spacing in this version. However, due to the large figures and tables in the end, still one larger empty space remained on page 14, adjusting the figures, that this space would be filled would be only possible by decreasing the size of some figures to a size too small to read.

3. & 4. To comment 3 and 4: in this small scale, it is not possible in our lab to quantify the amount of lost material in flue dust, which makes a scientific description of the losses impossible. Even in a larger scale (350 kg electrode mass), this is not possible by weighing dust etc. This was stated in a previous publication and is included now as well. Of course, it would be really good to know this, but sadly in the current state it is just not possible.

5. FactSage was cited at the point, where it was first mentioned with the appropriate citation taken from the “To cite FactSage in a publication, please use the following:” part from the FactSage homepage: http://www.factsage.com/fs_publications.php the citation is now added at all points were FactSage or a database was used. (The reference also includes the databases)

Kind regards,

Marcus Sommerfeld

Reviewer 2 Report

The manuscript presents an extensive study that demonstrates the possibility of recovering cobalt, nickel and copper with very good yields. Of course, the pyrometallurgical alternative also involves a high energy consumption and some difficulties in the subsequent hydrometallurgical treatment. I congratulate the team of authors for their valuable work.

Author Response

Thank you for reviewing, and I agree, there are still unsolved issues that should be considered before implementation.

Kind regards,

Marcus Sommerfeld

Reviewer 3 Report

Review

of the Manuscript

Title: A Combined Pyro- and Hydrometallurgical Approach to Recycle Pyrolyzed Lithium-Ion Battery Black Mass. Part 1: Production of Lithium Concentrates in an 4 Electric Arc Furnace.

Authors: Marcus Sommerfeld, Claudia Vonderstein, Christian Dertmann, Jakub Klimko, Dušan Orač, Andrea Miškufova, Tomaš Havlik, Bernd Friedrich.

1. Abstract. One half of the abstract is devoted to describing the state of the art in the supply of battery manufactures by raw materials. It is usual for Introduction but not for Abstracts where short list of derived scientific results should be presented only.

2. Content. Authors describe results of a suitable slag design for the generation of slag enriched by lithium and mixed cobalt, nickel and copper alloy as intermediate products in a laboratory electric arc furnace. They get the impressive results and present a combined pyro- and hydrometallurgical process, which enables a complete recovery of the valuable metals available in the black mass of spent LIBs. Derived results can present some interest for working companies but in real life, these companies are free to choose such a technology, and this publication may help them to make best choice.

            I recommend this article for publication in “Metals” and believe that this work will be useful for many readers who have interests in extraction processes.

Author Response

Thank you very much for reviewing the paper and your comments.

Based on your hints, the abstract was shortened now a little bit.

Kind regards,

Marcus Sommerfeld

Reviewer 4 Report

Review Report for Metals manuscript n. 884528

 A Combined Pyro- and Hydrometallurgical Approach to Recycle Pyrolyzed Lithium-Ion Battery Black Mass Part 1: Production of Lithium Concentrates in an Electric Arc Furnace

The topic of the paper is interesting and match the scopes of the journal. The paper shows the pyrometallurgical pre-treatment to concentrate cobalt, nickel, copper and lithium from spent lithium-ion batteries, that are becoming the first storage device for energy in many devices and equipment (together with Li-polymer accumulators). The car battery sector will use the majority of this metals and the possible shortage to face requires the recycling of such secondary raw materials.

1. Introduction

The innovation of the study and the differences with published literature are indicated at the end of this paragraph.

2. Materials & Methods

2.1 Used Materials

The results of the characterization of the black mass shall be moved to Results section, i.e. Table 1 and the relevant comments on it.

The work was huge, well planned and conducted. In my opinion it can certainly be published with minor revision. This recycling stage represents a crucial step for the following hydrometallurgical section, as the metals have greatly been concentrated, enhancing the recovery yield of the overall recycling process.

Author Response

Thank you very much for your time to review the paper.

I disagree with the comment "The results of the characterization of the black mass shall be moved to Results section, i.e. Table 1 and the relevant comments on it."

As the composition of the material is of significant importance for the thermochemical simulation, it has to be before the thermochemical simulation.

Kind regards,

Marcus Sommerfeld