The Experimental Study of Innovative Methods Regarding the Removal of Sm(III)

Round 1

Reviewer 1 Report

Interesting article that covers various methods of rare earth elements recovery. Comments: - the structure of the article should be divided into chapters like: 1.introduction, 2. materials and methods, 3. results and discussion, 4. conclusion. In the present form, chapters 2 and 3 are intertwined with each other, which does not correspond to the generally accepted structure of the publication in the journal, - the summary is very poor, requires refinement and emphasis on the correctness of the research and calculations performed. It is worth indicating the most advantageous method of REE recovery, - literature needs to be organized in accordance with the journal's guidelines. The publications of Russian authors dominate.        

Author Response

Honourable reviewer! 

We have tried to respond to your comments. 1. Fixed the structure of the article. 2. Changed the general name. 3. We have supplemented the list of references by foreign authors. 4. Replaced the paragraph: Conclusion

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript is reporting the recovery of REEs in various methods, such as flotation and sublation. The language of the manuscript needs significant improvement. The flow of the manuscript also needs further attention. The design and prosecution of the experiments sound correct but it is hard to follow the procedures due to the language of the manuscript.

Although Sm is part of rare earth elements, drawing a conclusion for 17 elements out of one is not appropriate statistically. Authors need to use Sm in the title of the manuscript rather than REE or REM.

Authors have failed to provide references when needed (Line 33-35, Fig1. Fig4, etc.)

Fig 4 is not cited in the manuscript. Also looks like Fig 4 is taken from the literature. If so, please include proper citation

 

Some detailed comments:

The tags on figure 2 are not correct (see cuvette and Stand)

There is a number of Cyrillic alphabets used in the manuscript. They should be removed.

In Table 1 what do the authors mean by "aqueous and organic phases" in flotation? 

Authors should provide the experimental procedure to obtain data presented in Table 1

 

 

 

Author Response

Honourable reviewer! We tried to take into account all your comments. Thanks

1.Changed the structure of the article for a better understanding

2.Fig.1 , Fig.4 is cited in manuscript

3."aqueous and organic phases" in flotation – «aqueous» denotes the content of Sm (III) in an aqueous solution, «organic» - foam is a foam product formed during flotation, containing NaDS and Sm (III).

4. 200 ml of samarium nitrate solution with the concentration of 0.001 mol/l and dry NaDS were added to the cuvette. The process continued no more than 5 minutes.

5. We set the pH of the solution - mix it. The foam product is separated (with H₂SO₄ is destroyed) from the aqueous phase - we analyze it for the content of Sm (III) and DS-ion

 

 

Reviewer 3 Report

In this manuscript, the researchers summarize their research on the recovery process of rare earths. The researchers evaluate three different recovery methods (ion flotation, solvent sublation and ion extraction) using samarium and discuss the correlation between pH and Gibbs energy and recovery efficiency. This initiative is very important because rare earths are essential metallic elements for advanced materials, and demand for them is expected to grow further in the future. However, the manuscript does not convey the novelty of this study and I feel it needs significant revision. There is also a misrepresentation of English grammar and many errors (see minor comments below). The manuscript is not complete enough.

 

Major comments

1) With regard to the title of this study, I think it would be better to use more specific terminology. It's too general and misleading.

2) In this manuscript, the experimental methods and results of three different rare-earth recovery processes are described separately. I think it would be better for the reader to understand if the introduction, experimental methods, results, and discussion were each combined into one section.

3) As for the abstract, it would be better to describe the numerical results and be more specific. Also, the phrase "In this paper" is unnecessary.

4) There is a lack of discussion for the results. For example, the researchers should emphasize for a detailed comparison of the three experimental methods, differences from the hypothesis, originality in this study, and future developments.

 

Minor comments

1) Figure 1 should be added to the reference paper.

2) The title in Figure 5 is far from the figure. Please correct it.

3) Figure 6: Please correct the pH of the horizontal axis.

4) Table 1 is divided into sections. I think it would be easier to read if they were unified.

5) The title of Table 4 is in bold text.

6) Table 3: Please correct the notation of Sm⁺³.

7) Table 5 is missing.

8) Please describe reference 28 correctly.

Author Response

Honourable reviewer! We tried to take into account all your comments. Thanks

We have changed the structure of the article for a better reading. The title of the article was changed

1.Studies of solutions containing other REE (Tb, Er) are planned. The originality of the experiment lies in the use of the method of solvent sublation and extraction with 2-octanol as an organic phase in solutions containing REE and NaDS.

2.Fig.1 is cited in manuscript, title of the Figure 5.  - Scheme of the extraction process in the NaDS - Sm(NO3)3 - 2-octanol system.

3. Fig.6 is correct
4. Changed the Conclusion paragraph
5. The name of Table 3 has been corrected.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The following comments should help you to perfect your manuscript.

Minor comments

1) Please make a new line and add a space.　Line No. 104, 165, 171, 237, 247, 256, 281, 317, 322, 323, 324 and 331.

2) Page 4: Please correct 'Figure 4' to 'Figure 3'.

3) Page 6: Please correct 'Figure 3' to 'Figure 4'.

4) Page 7: Please correct 'table 3, 4' to 'table 3 and 4'.

5) Page 9, Figure 6: Please correct the pH of the horizontal axis. For example, 4,0 to 4.0.

6) Page 9, Figure 6: The range of the horizontal axis should be 3.0 to 6.0. Also, there is no such condition as pH = 0. If you have data below pH 3.0, you should add it.

7) Regarding the titles of figures and tables, the font size is mixed between 9 and 10. Please unify them.

Author Response

Dear reviewer,
Thank you very much for your review. I delayed the answer – I got sick with a high fever – but I tried to take into account all your comments:
1-added a new line and a space – all the lines that you specified.
2 - corrected figure numbers – 4 fixed at 3.
3 – figure 3 changed figure 4.
4 - table of 3,4 – written as in table 3 and 4.
5 – fixed horizontal axis in figure 6.
6 –the horizontal axis of the figure made from 3.0 to 6.0.
7 – all titles of graphics and tables unify font 9.
Thank you again very much.
With respect
O.Lobacheva

Author Response File: Author Response.docx