Brazilian Coal Tailings Projects: Advanced Study of Sustainable Using FIB-SEM and HR-TEM

Round 1

Reviewer 1 Report

Comments for author File: Comments.pdf

Author Response

Dear Editor

 

Thank you for taking the time to manage this editorial process and for sending us the following review comments for revision.

 

We have revised our paper, accommodating each and every comment. We provide below a point-by-point reply to the comments.

 

We reinforce that we are satisfied with the reviewers' recommendation. In this context, the corrections requested by the reviewers were carried out in detail, thus meeting the reviewers' suggestions.

____________________________________________________________

Reviewer’s Comments

First, we wish to thank the reviewers for evaluating our manuscript. We revised the manuscript according to the 3rd anonymous reviewer, along with their comments. Reviewer comments and author responses are shown below in two different colors. We hope that you will consider our manuscript for publication in your esteemed journal. The manuscript is original, no part of the manuscript has been published before, nor is any part of it being considered for publication in any other journal. We express our immense thanks for taking the time to complete this review. For, without a doubt, it helped to improve the overall quality of this manuscript. Many thanks!

 

REVIEWER 1

This interesting manuscript ID: sustainability-2060396 with the title: Brazilian coal tailings projects: advanced study of sustainable using FIB-SEM and HRTEM deals with the qualification and quantification of Monazite and Xenotime contained in these coal fine sample, which are associated with the environmental and human health issues during combustion. These high-value rare earth elements (REEs) which are associated with these nano-phosphate minerals should be recovered from either fine coal waste particles or fine coal ash using suitable lixiviants. During and after the reviewing of this paper, I found that almost all sections of it were written and presented well following the sustainability journal guides for authors. Furthermore, the results significance obtained from the study in the commercial plants and research institutions are highlighted in the abstract and the conclusions sections. Following my comments below, the fascinating results obtained from this investigation should undoubtedly be recommended to publish in this international peer-reviewed journal after minor revisions.

Authors respond: We convey our immense thanks for dedicating your time to this evaluation. It definitely helped improve the quality of this manuscript. Thank you for your kind words regarding the quality of this study. Thanks.

 

General Remarks:

1) The authors of this paper must state the size of the coal fines characterized in the abstract section and they must do so throughout the manuscript.

Authors' response: Thank you for pointing this out. To address this, we clarified in the text that the abandoned area in which our samples were obtained contained rocks and particles ranging from giant rocks to nanoparticles of coal. The particle size at the site was incredibly heterogenous. This markedly improved the quality of the manuscript text. Thank you for helping us to improve the quality of this study.

 

2) The authors must prepare a paragraph at the end of the introduction section merging this section and the proceeding section which is the materials and methods, stating analytical techniques to be used to characterize all samples from this study.

Authors' response: Thank you for highlighting this. To resolve this, a text containing this explanation was added, as recommended at the end of the introduction. Thank you for helping us to improve the quality of the manuscript text.

 

3) In the experimental section of the manuscript, the authors must state the location, model, year, supplier of each equipment utilized to characterize the samples from the investigation.

Authors' response: Thank you for this suggestion. The requested data were inserted into the text of the manuscript, as recommended. Thank you for helping us to improve the quality of the manuscript text.

 

4) On Page 7 replace metals with metallic inorganic elements. And for the consistency, please do so throughout the manuscript.

Authors' response: As requested, the term metals was replaced by metallic inorganic elements throughout the text. Thank you for helping us to improve the quality of the manuscript text.

 

5) In the second sentence on Page 8, also the XRD cannot detect the submicron particles of nanominerals due to the smaller sizes.

Authors' response: Thank you for pointing this out. Initially, we didn't really notice this in the text. However, after reading your comment, this was corrected. Thank you for helping us to improve the quality of the manuscript text.

Authors respond: Thank you very much for taking the time to make these suggestions regarding the revision of our manuscript, thus markedly improving it overall. Thanks.

We also point out that the text was submitted to a specialized professional who is a native English speaker, specializing in translating scientific manuscripts and to an agency specializing in spelling corrections to correct possible spelling errors in the manuscript.

We are very grateful for the invaluable contributions generated by the reviewers, which further improved the quality of the manuscript. Technically, the only word of thanks we can express is sincere Gratitude.

 

Yours very sincerely,

___________________

Corresponding authors

Reviewer 2 Report

This paper provides a more detailed assessment of particles containing rare-earth elements (REEs) in the abandoned deposits of Brazilian fine coal tailings (BFCTs), so that the current coal mining industry can find ways to extract these elements. The writing is standardized, the thinking is clear. But at the same time, I also found some problems in the paper. I hope the author can revise it well to improve the quality of the paper.

（1）What is the research status of this paper on the evaluation of particles containing rare-earth elements (REEs) in abandoned deposits? It is suggested to add some information.

（2）The coal energy structure in Brazil needs to be summarized, because this is a background of this article, which is very important.

（3）In the section of laboratory analysis procedures, it is recommended to make a flow chart for the reader to understand.

（4）Figure 4 Need to mark the magnification

（5）Table 2 changed to three line table.

（6）What is the global average concentration of coals? This data needs to be added for better comparison.

 

Author Response

Dear Editor

Thank you for taking the time to manage this editorial process and for sending us the following review comments for revision.

We have revised our paper, accommodating each and every comment. We provide below a point-by-point reply to the comments.

 

We reinforce that we are satisfied with the reviewers' recommendation. In this context, the corrections requested by the reviewers were carried out in detail, thus meeting the reviewers' suggestions.

____________________________________________________________

Reviewer’s Comments

First, we wish to thank the reviewers for evaluating our manuscript. We revised the manuscript according to the 3rd anonymous reviewer, along with their comments. Reviewer comments and author responses are shown below in two different colors. We hope that you will consider our manuscript for publication in your esteemed journal. The manuscript is original, no part of the manuscript has been published before, nor is any part of it being considered for publication in any other journal. We express our immense thanks for taking the time to complete this review. For, without a doubt, it helped to improve the overall quality of this manuscript. Many thanks!

REVIEWER 2

This paper provides a more detailed assessment of particles containing rare-earth elements (REEs) in the abandoned deposits of Brazilian fine coal tailings (BFCTs), so that the current coal mining industry can find ways to extract these elements. The writing is standardized, the thinking is clear. But at the same time, I also found some problems in the paper. I hope the author can revise it well to improve the quality of the paper.

Authors respond: We convey our immense thanks for dedicating your time to this evaluation. It definitely helped improve the overall quality of this manuscript. Thank you for your kind words regarding the quality agreement of this study.

 

（1）What is the research status of this paper on the evaluation of particles containing rare-earth elements (REEs) in abandoned deposits? It is suggested to add some information.

Authors' response: Thank you for pointing this out. Text containing this explanation was added, as recommended, at the end of the introduction. Thank you for helping us to improve the quality of the manuscript text.

 

（2）The coal energy structure in Brazil needs to be summarized, because this is a background of this article, which is very important.

Authors' response: Thank you for pointing out this item. As suggested, this has been made clearer in the manuscript text. Thank you for helping us to improve the quality of the manuscript text.

 

（3）In the section of laboratory analysis procedures, it is recommended to make a flow chart for the reader to understand.

Authors' response: Thank you for making this suggestion. To adequately address this recommendation, we improved the text of the procedures and inserted Figure 3, aiming to provide a better representation of the place where the sediments were collected and the equipment used in the laboratory. Thank you for helping us to markedly improve the quality of the manuscript text.

 

（4）Figure 4 needs to mark the magnification

Authors' response: Thank you for pointing this out. We inform you that the scale is already included and that it is not possible to enlarge the magnification, as the image is provided directly by the system used. Thank you very much for your note.

 

（5）Table 2 changed to three-line table.

Authors' response: Thank you. To address this, we standardized Table 2 in relation to the other tables. Thank you for helping us to improve the quality of our manuscript.

 

（6）What is the global average concentration of coals? This data needs to be added for better comparison.

Authors' response: Thank you for pointing out this item. To address this omission, we inserted this data into the manuscript’s introduction. Thank you for helping us to improve the quality of our manuscript.

 

Authors respond: Thank you very much for taking the time to make these suggestions regarding the revision of our manuscript, thus markedly improving its overall quality. Thanks.

We also point out that the text was submitted to a specialized professional who is a native English speaker, specializing in translating scientific manuscripts and to an agency specializing in spelling corrections to correct possible spelling errors in the manuscript.

We are very grateful for the invaluable contributions generated by the reviewers, which further improved the quality of the manuscript. Technically, the only word of thanks we can express is sincere Gratitude.

 

Yours very sincerely,

___________________

Corresponding authors

Reviewer 3 Report

The manuscript entitled ‘Brazilian coal tailings projects: advanced sustainability study using FIB-SEM and HR-TEM’ analyzes by SEM, EDX, TEM, ICP-AES and ICP-MS the abandoned deposits of industries that extracted coal in two Brazilian locations. The objective is to find rare earth elements in the analyzed samples. On the contrary, it does not show any TEM image or FIB preparation. It does not show any results of Raman spectroscopy, although in the abstract it states that they have analyzed it; it does not even mention this technique again in the article. In my opinion, this article should not be published in Sustainability. In any case, he made some comments that can help the authors improve the article:

1) In the experimental part, they must include the brand, model, and analysis conditions of all the techniques used in the study.

2) Both the SEM and TEM images, EDX spectra, and the diffraction patterns used for crystal indexing, as well as the ICP-AES and ICP-MS spectra must be included, at least in the supporting information. It would be interesting if a representative example of each technique used in the manuscript. They should clearly explain how they determine the presence of each mineral so that their reliability is not in doubt.

3) The foot of the Figure 3 must be changed because what is shown seems to be an EDX mapping with Fe, Al, S and O. They state that they are Melanterite (FeSO4 7H2O) and Rozenite (Fe2+SO4 4H2O) but they also show the presence of Al and no element quantization.

4) On page 8, the authors state that thanks to the FIB preparation, the Monozite and Xenotime clays can be located inside, but Figure 5 shows an agglomerate where a superficial EDX was performed. The EDX spectrum of the region of interest should be displayed.

 

5) The authors state in the last paragraph of Results and Discussion that nanoparticles with REE and hazardous elements are shown to have different crystal structures, geochemical preparation, thermodynamic equilibrium and physical characteristics compared to the characteristics of micro or macroparticles. Which is totally false, it shows no evidence of that fact.

Author Response

Dear Editor

Thank you for taking the time to manage this editorial process and for sending us the following review comments for revision.

We have revised our paper, accommodating each and every comment. We provide below a point-by-point reply to the comments.

We reinforce that we are satisfied with the reviewers' recommendation. In this context, the corrections requested by the reviewers were carried out in detail, thus meeting the reviewers' suggestions.

____________________________________________________________

Reviewer’s Comments

First, we wish to thank the reviewers for evaluating our manuscript. We revised the manuscript according to the 3rd anonymous reviewer, along with their comments. Reviewer comments and author responses are shown below in two different colors. We hope that you will consider our manuscript for publication in your esteemed journal. The manuscript is original, no part of the manuscript has been published before, nor is any part of it being considered for publication in any other journal. We express our immense thanks for taking the time to complete this review. For, without a doubt, it helped to improve the overall quality of this manuscript. Many thanks!

REVIEWER 3

The manuscript entitled ‘Brazilian coal tailings projects: advanced sustainability study using FIB-SEM and HR-TEM’ analyzes by SEM, EDX, TEM, ICP-AES and ICP-MS the abandoned deposits of industries that extracted coal in two Brazilian locations. The objective is to find rare earth elements in the analyzed samples. On the contrary, it does not show any TEM image or FIB preparation. It does not show any results of Raman spectroscopy, although in the abstract it states that they have analyzed it; it does not even mention this technique again in the article. In my opinion, this article should not be published in Sustainability. In any case, he made some comments that can help the authors improve the article:

Authors respond: We convey our immense thanks for dedicating your time to this evaluation. It definitely helped improve the quality of this manuscript. We thank you for the opinion given, we emphasize that we respect your decision very much. Although the authors and other designated reviewers do not agree with this opinion as stated. Thank you for your notes, which were all answered.

 

1) In the experimental part, they must include the brand, model, and analysis conditions of all the techniques used in the study.

Authors' response: Thank you for pointing this out. To address this, the requested data were inserted into the text of the manuscript, as recommended. Thank you for helping us to improve the quality of the manuscript text.

 

2) Both the SEM and TEM images, EDX spectra, and the diffraction patterns used for crystal indexing, as well as the ICP-AES and ICP-MS spectra must be included, at least in the supporting information. It would be interesting if a representative example of each technique used in the manuscript. They should clearly explain how they determine the presence of each mineral so that their reliability is not in doubt.

Authors' response: Thank you for pointing out this item. We respectfully inform you that this information can already be found in the manuscript, in the figures that contain each technique. If a particle is smaller in size than 100 nm, it is classified as a TEM. If it is larger, it is classified as a SEM. We appreciate your concern about the quality of the manuscript.

 

3) The foot of the Figure 3 must be changed because what is shown seems to be an EDX mapping with Fe, Al, S and O. They state that they are Melanterite (FeSO4 7H2O) and Rozenite (Fe2+SO4 4H2O) but they also show the presence of Al and no element quantization.

Authors' response: Thank you for pointing this out. To address this, Al, K and Mg are now described as clays and amorphous phases, which were also detected as minority fractions associated with iron sulfate phases, the figure’s caption now states this. Thank you for helping us to improve the written quality of the manuscript text.

 

4) On page 8, the authors state that thanks to the FIB preparation, the Monozite and Xenotime clays can be located inside, but Figure 5 shows an agglomerate where a superficial EDX was performed. The EDX spectrum of the region of interest should be displayed.

Authors' response: Thank you for the suggestion, which we will consider for future articles, but for this one it is too late, as this is only possible to obtain at the moment when the photo of the particle is taken. As we currently do not record the information, it will not be possible to add the EDS. Thank you though for making this helpful suggestion regarding future studies. Thanks.

 

5) The authors state in the last paragraph of Results and Discussion that nanoparticles with REE and hazardous elements are shown to have different crystal structures, geochemical preparation, thermodynamic equilibrium and physical characteristics compared to the characteristics of micro or macroparticles. Which is totally false, it shows no evidence of that fact.

Authors' response: Respectfully, we emphasize that it is unethical to state that the authors are being false, especially considering that they routinely publish in respected journals in the area of nanominerals, which demonstrates the quality of the authors’ work. Respectfully, thank you.

 

Authors respond: Thank you very much for taking the time to make these suggestions regarding the revision of our manuscript, thus markedly improving its overall quality. Thanks.

We also point out that the text was submitted to a specialized professional who is a native English speaker, specializing in translating scientific manuscripts and to an agency specializing in spelling corrections to correct possible spelling errors in the manuscript.

We are very grateful for the invaluable contributions generated by the reviewers, which further improved the quality of the manuscript. Technically, the only word of thanks we can express is sincere Gratitude.

 

Yours very sincerely,

___________________

Corresponding authors

 

Round 2

Reviewer 3 Report

The new manuscript does not correct all the suggestions I made to the authors. SEM, TEM images, EDX spectra, and the diffraction patterns used for crystal indexing must be included, at least in the supporting information.

Author Response

Dear

Respectfully, I say that it is impossible, since it must be saved when the particle is photographed. Once the results were noted, we proceeded with the analyses. We've done this in over 100 articles and many already have over 100 citations. But we appreciate the concern
Thanks