Sustainable Production of Rare Earth Elements from Mine Waste and Geoethics

Round 1

Reviewer 1 Report

This manuscript presents data concerning to the recovery rare earth elements (REE) from secondary sources (SM) as electrical waste, mine tailings, contaminated residuals from mine drainage treatment, red mud, and phosphogypsum. Authors applied LCIA method (life cycle impact assessment method) to make a comparison between primary and secondary resources of REE extraction. A few LCIA studies on the production of REEs from secondary or non-alternative resources have been published to date. The results show that REEs recovery from SM generated positive impact in several categories for example potential particulate matter formation, however, high fresh water eutrophication and ionizing radiation potential could be encountered during the processing.

 

This study present novel and interesting data however it has couple of shortcomings which should improve the paper

 

1)      Introduction: I think,  Mining: Sustainability, Circular Economy, and Geoethics, should be included within the introduction section

2)      Materials and Method: I would prefer that the authors add Sections:  

2. Materials and Method,

2.1 Methodology: Geoethics of REE Extraction from Primary vs Secondary Sources

In this section, it is not clear what kind of secondary source materials were involve for compare with primary source (B/M/S/E and IAC).

Please, in page 8, line 281: in Figure 3, you could clarify what type of secondary resources you are referring to?.

3)     Results

The Table A1 to A4 of Appendix A, the following abbreviation: LREO-HREO, REO need to be clarified in a footnote in each table. The Tables and legend together should be understandable without having to refer to the main text

 

4)     Discussion

Generally I think the discussion is good and well written, but it would be better if included this paper:  Pyrgaki, K.; Gemeni, V.; Karkalis, C.; Koukouzas, N.;

Koutsovitis, P.; Petrounias, P. Geochemical Occurrence of Rare Earth Elements in MiningWaste and MineWater: A Review. Minerals 2021,11, 860. https://doi.org/10.3390/min11080860

 

5)     References

All references need to be checked. After the year replace the dot with a comma, please. Pay attention to the instruction for author to cited and write the references, again.

Comments for author File: Comments.pdf

Author Response

Please refer to the enclosed file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments on Jouini et al.

Journal: Minerals
Manuscript ID: minerals-1749666
Title: Sustainable production of rare earth elements from mine waste and Geoethics
Authors: Marouen Jouini , Alexandre Royen-Lavallée , Thomas Pabst , Eunhyea Chung , Rina Kim , Young-Wook Cheong , Carmen Mihaela Neculita *

This manuscript calculates potential environmental and social impacts of extracting rare earth elements (REEs) from primary ores such as bastnäsite, monazite, synchysite, and eudialyte minerals; from primary ion-adsorption clay deposits; and from secondary materials (SM) such as tailings, magnets, fluorescent powders, etc.

Comments:  

This is a good manuscript and worthy of publication. It is well written and organized. The descriptions of the concept of Geoethics and the method of analysis, the quantification of social and environmental impacts using life cycle impact assessment (LCIA), are appropriate. The paper includes the detailed and fully referenced input parameters for the analysis in the Appendix. The figures are well presented. Only one typographical error (spelling of xenotime in line 195) was noticed. Congratulations on a great manuscript.

Author Response

Please refer to the enclosed file

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper deals with REEs mining and makes considerations about best methods to mine REEs by considering a geoethical framework of reference.

The text is quite clear and written in a good English.

This paper is worthy to be published after some changes, especially related to correct citations to works on geoethics.

Paper’s authors have listed several important papers on geoethics and even some few others may be cited. There are problems with the citation of a self-published book (see citation [8]) that should not be accepted into a peer-review paper of a scientific journal, considering also that there are other more important and peer-reviewed papers, chapters in edited book, or books on the same geoethical considerations that can replace that citation.

In my opinion, authors should briefly discuss in the conclusion if secondary REEs have been also the potential to provide all REEs that industry needs worldwide, or if the conclusion of the paper are consistent with the proposal to reduce primary mining of a percentage to be replaced by the secondary mining. This is a very important point that should be clarified.

Finally, the list of references is quite appropriate, some detailed suggestions have been included in the detailed comments on the manuscript.

Some detailed comments about this paper are in the pdf file of the manuscript.

Comments for author File: Comments.pdf

Author Response

Please refer to the enclosed file

Author Response File: Author Response.pdf