Flocculation and Settlement Characteristics of Ultrafine Tailings and Microscopic Characteristics of Flocs
Round 1
Reviewer 1 Report
C. Han et al. have studied the effect of four flocculants on the sedimentation process of material coming from Daye Iron Mine, Hubei, China. It was found that AZ9020 afforded best results, when used 30g/t (solution concentration 0.3%). with full tailings flocculation to sizes less than 0.1 micron, and a sedimentation time around 45 min.
In general, the manuscript is well-written, and the data is presented accordingly.
There are, however, a few observations:
- table 1 : what is the unit for SSA? cm2/cm3 seems counterintuitive and hard to compare to typical values for SSA.
- Several subscripts for formulae are missing: lines 94-95.
- Same lines: what are TFe and SFe ? They don’t correspond to any real chemical formula.
- Same goes for Table 2 (same 2 as above)
- Line 109: “mixingz”
- Formulae for AZ358...AZ9020 should be given to prove their anionic nature;
- Justification for using anionic type flocculants (chemical reactions?) should be tentatively written;
- Table 4: Unit consumption for 5 in experiment 2 is missing?
- Fig 4b should be kept as scattered points, due to large variance and lack of a clear trend.
- Since image binarization introduces some degree of bias, What's the value of threshold T used? And how was it chosen? (line 267)
- On line 284: Fractal dimensions D are largely the same; have other flocculants been investigated? Perhaps flocculants of other type or MW would work better.
- How were the 3 locations chosen? Based on what criteria? I assume each flocculant afforded different final height of the sediment measured at a given time.
- Section 4.1.1 : Where are the NMR spectra? Where is the direct interpretation of these spectra
I suggest revision of the manuscript taking note of the observations above.
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
We agree with some of these suggestions and have revised the manuscript according to your editorial comments and advice. To better display the revised content, the manuscript was revised using the "Track Changes" function in Microsoft Word, and all the changes to the original text is easy to track.
We also answered your questions, which may readers will have. Below is our response to your questions and technical comments resulting in a number of clarifications and marked as red.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 1 Comments
Point 1: table 1 what is the unit for SSA? cm2/cm3 seems counterintuitive and hard to compare to typical values for SSA. Several subscripts for formulae are missing: lines 94-95.
Response 1: I'm terribly sorry for my mistake. "Cm2 /cm3" is wrong. After reviewing the literature, it is found that the specific surface area in the paper should be changed to the specific surface area by weight, and the unit is m2/kg. It has been changed in the original text.
Point 2: Same lines: what are TFe and SFe ? They don’t correspond to any real chemical formula.Same goes for Table 2 (same 2 as above) Line 109: “mixingz”.
Response 2: TFe means Total iron or Total iron, (Total Fe). In iron and steel metallurgy, TFe represents the total iron, that is, the proportion of iron elements in various forms in iron ore or steel slag and other iron-containing materials, such as the proportion of total iron in steel slag, including steel balls, ferrous oxide, ferric oxide, ferric oxide and other ionic iron. For example, in reduced iron powder, there are not only elemental iron, iron oxide, and other types of iron such as iron silicate. TFe is the sum of these types of iron. And SFe is the sum of iron sulfide.
“mixingz” has been changed in the original text.
Point 3: Formulae for AZ358...AZ9020 should be given to prove their anionic nature;
Justification for using anionic type flocculants (chemical reactions?) should be tentatively written;
Response 3: Based on the reference studies, it was shown that anionic flocculants had a better flocculation effect on tailings, which was preliminarily listed in this paper, Line 100 . And table 3 is the Technical Index of anionic flocculant .
Point 4: Table 4: Unit consumption for 5 in experiment 2 is missing?
Fig 4b should be kept as scattered points, due to large variance and lack of a clear trend.
Response 4: Table 4 and Figure 4 have been modified in the original text.
Point 5: Since image binarization introduces some degree of bias, What's the value of threshold T used? And how was it chosen? (line 267)?
Response 5: I adopted was 65~255 of the image binarization threshold T, which was based on my experience in processing such images in our research group at that time. The binarization images with the value of 65~255 were relatively clear and the differences of different flocculants could be accurately observed. So we use this number.
Point 6: On line 284: Fractal dimensions D are largely the same; have other flocculants been investigated? Perhaps flocculants of other type or MW would work better.
Response 6: I am sorry that I did not carry out research on other types of flocculants. The NMR experiment only used 4 flocculants consistent with the above. This was due to the limitation of experimental funds and experimental materials at that time, no other types of flocculant research was carried out.
Point 7: How were the 3 locations chosen? Based on what criteria? I assume each flocculant afforded different final height of the sediment measured at a given time.
Response 7: The content of electron microscope experiment is the difference of floc structure at different heights, and the sampling standard is representative sampling at different heights at the same location. Since the height of the tailings settled after the experiment reached about 350mL on the scale, samples were taken at 100\200\300 mL on the scale according to the standard of isometric sampling.
Point 8: Section 4.1.1 : Where are the NMR spectra? Where is the direct interpretation of these spectra
Response 8: The NMR spectrum is shown as the hydrogen spectrum, and the direct explanation is expressed in line 183 of the literature.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors of the manuscript minerals-1550635 investigated the flocculation and sedimentation performance of the ultrafine whole tailings adopting varied flocculants and made an explanation from a microscopic view. Some issues listed below need to be considered and revised.
(1) The innovation in this manuscript is insufficient. It is recommended to provide some comparative data of relevant researches.
(2) The relationship between the sample color in SEM and water content is lack of literature support.
(3) The mechanism that varied flocculants contribute to the sediments with varied morphology need to be illustrated. The SEM images is recommended to remain at a same scale.
Whether the morphology change mentioned is universal or accidental? The SEM images is too local to be sufficient.
(4) How to distinguish the compactness of the flocs? What is the relationship between the compactness and the morphology of the flocs?
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
We agree with some of these suggestions and have revised the manuscript according to your editorial comments and advice. To better display the revised content, the manuscript was revised using the "Track Changes" function in Microsoft Word, and all the changes to the original text is easy to track.
We also answered your questions, which may readers will have. Below is our response to your questions and technical comments resulting in a number of clarifications and marked as red.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 2 Comments
Point 1: The innovation in this manuscript is insufficient. It is recommended to provide some comparative data of relevant researches.
Response 1: This paper is based on our research group's previous studies on similar substances. Their studies mainly focus on the flocculation and sedimentation characteristics of fine tailings and flocculants. On this basis, I studied the flocculation and sedimentation characteristics of full tailings under another four flocculants. Previous papers published by our research group include Di Zheng, Wei-dong Song, Yu-ye Tan, Shuai Cao, Zi-long Yang, and Li-Juan Sun, Research on fractal and microscopic quantitative characterization of unclassified tailings flocs, Int. J. Miner. Metall. Mater. https://doi.org/10.1007/s12613-020-2181-2.
Point 2: The relationship between the sample color in SEM and water content is lack of literature support..
Response 2: The relationship between sample color and water content in electron microscopy is indeed lack of literature support. This paper only summarizes the relationship between sample color and water content based on the experimental phenomena in this paper.
Point 3:The mechanism that varied flocculants contribute to the sediments with varied morphology need to be illustrated. The SEM images is recommended to remain at a same scale. Whether the morphology change mentioned is universal or accidental? The SEM images is too local to be sufficient.
Response 3: According to the study in this paper, AZ9020 flocculant formed the flocculant solution with more pores of small pore size, so the flocculant structure is more compact, while other types of flocculant have more pores of small pore size and smaller pores, so the flocculant structure is more loose. The SEM images used in the experiment in this paper are of the same proportion, with magnification of 2000 times. The morphological changes mentioned are universal, and there are universal rules according to the research of our research group (as shown in point 1).
Point 4: How to distinguish the compactness of the flocs? What is the relationship between the compactness and the morphology of the flocs?
Response 4: The relationship between the compactness and morphology of flocs is mainly determined by the size of pores shown on the morphology of samples, and the compactness of flocs is studied by the proportion of pores of small pore size in flocs solution, that is, the proportion of pores of small pore size is more, and the flocs structure is more compact. For example, the relationship between porosity and pore size obtained by NMR experiment (Figure 9) and pore diameter obtained by SEM experiment (Figure 16).
Author Response File: Author Response.pdf
Reviewer 3 Report
1. The title could be shorter and more profound, and line 1 (select paper type).
2. To prolonged lines, needs to be in short sentences. see abstract 4 lines,
3. Article needs English proofreading and technical checks, so many typos and complex sentences.
4. That fine no need to write keywords numbering, its not MDPI formate.
5. The references pattern and style are not as per MDPI, need to revise. Line 42,48,50,52- the citation is not added in the correct place, it could be as Jiao(year) and then numbering style at end of the line.
6. Figure 1, Chinese language is visible, may I ask are you targeting the only chinees audience or the whole world. needs to follow international standards.
7. Table 1, Figure 1, why capitalization each word, may I ask why ???
8. Limitation of study and future study contribution seeds to be added in separate headings.
References instruction needs to be skipped when has to follow the mdpi template. The referencing style is not matched with the requirements.
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
We agree with some of these suggestions and have revised the manuscript according to your editorial comments and advice. To better display the revised content, the manuscript was revised using the "Track Changes" function in Microsoft Word, and all the changes to the original text is easy to track.
We also answered your questions, which may readers will have. Below is our response to your questions and technical comments resulting in a number of clarifications and marked as red.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 3 Comments
Point 1: The title could be shorter and more profound, and line 1 (select paper type).
Response 1: The title has been corrected in the article.（ Line 1）
Point 2: To prolonged lines, needs to be in short sentences. see abstract 4 lines,
Response 2: Correction has been made in the abstract. (Line10~14).
Point 3: Article needs English proofreading and technical checks, so many typos and complex sentences.
Response 3: This article has been proofread and polished in English. please feel free to comment if there are any mistakes.
Point 4: That fine no need to write keywords numbering, its not MDPI formate.
Response 4: keywords has been corrected .（line 31）
Point 5: The references pattern and style are not as per MDPI, need to revise. Line 42,48,50,52- the citation is not added in the correct place, it could be as Jiao(year) and then numbering style at end of the line.
Response 5: The references have been corrected in the literature. All numbering styles have beenat end of the line, and the references at the end of the literature have been corrected as required.
Point 6: Figure 1, Chinese language is visible, may I ask are you targeting the only chinees audience or the whole world. needs to follow international standards.
Response 6: The Chinese of Figure 1 has been corrected. I am very sorry that this is an editing error.
Point 7: Table 1, Figure 1, why capitalization each word, may I ask why ???
Response 7: I only capitalized the first letter of each word in Figure 1 and Table 1, which was written according to Minerals' paper template and a review of the published literature in this journal.
Point 8: Limitation of study and future study contribution seeds to be added in separate headings.
Response 8: It has been added in this literature. Thank you very much.
Author Response File: Author Response.pdf
Reviewer 4 Report
In the present manuscript, nuclear magnetic resonance and micro-electron microscopy were adopted to investigate the microstructure characteristics of ultrafine tailings during flocculation and sedimentation in the Daye Iron Mine. It has been found that the best addition amount of AZ9020 flocculant is 30 g/t, and the stirring time is more than 45 17 min. However, this manuscript needs some modifications before it can be accepted for publication as follows:
- Abstract, Line 17: what is AZ9020? It must be described as an anionic flocculant.
- All symbols and abbreviations used in the manuscript must be explained from their first appearance; see Lines 76 and 178. This comment applies to the whole manuscript.
- The numbering of the sections must be modified:
- 1.2 must be corrected to be 2.2
- 3.1 must be moved to section 2 as Sec. 2.3
- 3.1 Experimental program and process: a flowchart must be added to simplify understanding for the reader.
- The title of Sec. 3 must be corrected to be "Results and Discussion"
- Merge Sec. 3.2.1 to 3.2.4 to be Sec. 3.1. The title of this section should be "The influence of flocculant parameters on the settlement effect of ultrafine tailings"
- Change the number of Sec. 4. to 3.2 and merge all subsections.
- The conclusion should be reduced.
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
We agree with some of these suggestions and have revised the manuscript according to your editorial comments and advice. To better display the revised content, the manuscript was revised using the "Track Changes" function in Microsoft Word, and all the changes to the original text is easy to track.
We also answered your questions, which may readers will have. Below is our response to your questions and technical comments resulting in a number of clarifications and marked as red.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 4 Comments
Point 1: Abstract, Line 17: what is AZ9020? It must be described as an anionic flocculant.
All symbols and abbreviations used in the manuscript must be explained from their first appearance; see Lines 76 and 178. This comment applies to the whole manuscript.
Response 1: This has been changed in the article and has been described as an anionic flocculant. The abbreviations have been modified.
Point 2: The numbering of the sections must be modified:
1.2 must be corrected to be 2.2
3.1 must be moved to section 2 as Sec. 2.3
3.1 Experimental program and process: a flowchart must be added to simplify understanding for the reader.
Response 2: I am very sorry, the editing error has been corrected in the article. The structure of the article has been modified as required, please check it in the article.
In the literature, 3.1.1 has be moved to section 2 as Sec. 2.3, 4.1.1 has be moved to section 2 as Sec. 2.4, 4.1.2 has be moved to section 2 as Sec. 2.5,
Point 3: The title of Sec. 3 must be corrected to be "Results and Discussion"
Merge Sec. 3.2.1 to 3.2.4 to be Sec. 3.1. The title of this section should be "The influence of flocculant parameters on the settlement effect of ultrafine tailings"
Change the number of Sec. 4. to 3.2 and merge all subsections.
The conclusion should be reduced.
Response 3: The structure of the article has been modified as required, please check it in the article. In the literature, 3.2.1 to 3.2.4 to be Sec. 3.1, 4.2.1 to 4.2.2 to be Sec. 3.2, and 4.2.3 to 4.2.5 to be Sec. 3.3. The conclusion has be reduced.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
While some comments have been addressed, I still don't see the NMR spectra (Fig. 3). The introduction of NMR part describing what NMR stands for, is really not needed, moreover when one showns no such spectrum. I recommend including the NMR spectrum before publication.
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
We agree with some of these suggestions and have revised the manuscript according to your editorial comments and advice. To better display the revised content, the manuscript was revised using the "Track Changes" function in Microsoft Word, and all the changes to the original text is easy to track.
We also answered your questions, which may readers will have. Below is our response to your questions and technical comments resulting in a number of clarifications and marked as red.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 1 Comments
Point 1: While some comments have been addressed, I still don't see the NMR spectra (Fig. 3). The introduction of NMR part describing what NMR stands for, is really not needed, moreover when one showns no such spectrum. I recommend including the NMR spectrum before publication.
Response 1: The introduction of NMR part describing what NMR stands for has been deleted(Line 114). The NMR spectrum has been added to FIG. 3 a (Line 134) and FIG. 9 b (Line224) . Thank you very much for your inspection.
Reviewer 3 Report
Thank you for providing the report. I still think one round of English correction is required and after the proofreading round, it is recommended from my side for acceptance.
Author Response
Dear reviewer,
We appreciate the very useful and detail comments from you.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
Response to Reviewer 3 Comments
Point 1: I still think one round of English correction is required and after the proofreading round, it is recommended from my side for acceptance.
Response 1: I have submitted the English editing service on minerals platform, and the editorial department has revised the literature. Thank you very much for your reply.
Reviewer 4 Report
The authors have successfully addressed most of my comments. Therefore, I recommend the publication of this manuscript.
Author Response
Response to Reviewer 4 Comments
Dear reviewer,
We appreciate the very useful and detail comments from you.
Thanks very much for all the helpful work you did to improve the manuscripts.
Best Regards
All authors
