Study on Natural Settlement Index Characteristics of Iron-Bearing Tailings Applied to Goaf Filling Treatment
Round 1
Reviewer 1 Report
Authors with the tests of subsidence concentration and subsidence bulk density and the transportation indicate that the natural subsidence of the low-concentration tailing slurry meets the requirements of the backfill process.
I found great value in your paper and feel that it will take a bit more time and effort to make it suitable for publication. Rather than hold onto your paper, I hope that you will revise it at your convenience and continue to revise your paper and find the helpful comments and suggestions I provide below.
The manuscript in light of my suggestions, and opinion is that after reading the paper, the manuscript is of potential interest to the readership of this journal, but there are significant issues that must be addressed before the article could be published:
Introduction:
The introduction needs to be developed further to establish the justification/ importance of the new initiative and articulate the research problem and objective; these need to be linked explicitly to the associated issues and problems. The introduction would benefit from a succinct description of the paper and a stronger emphasis on the problem addressed by the research.
The introduction flow can be improved by discussing the paper's research problem.
A further critical discussion needs to be done to concretize the issues/ problem statement.
Literature review
The LR section can be improved by including recent studies and identifying and drawing upon the critical body of knowledge relevant to the research, including learning theories. Overall, the literature review needs to be strengthened to emphasize the real-world significance of the issues addressed, and this informs the research design; the theoretical framework emerging from the literature review should relate to the research questions and points of emphasis.
The literature review should be more carefully synthesized and structured. The author can use sub-headings and signposting to help the reader follow the developed argument and improve the paper's readability. Consider also the following suggestions:
1. a) Include a few introductory lines to indicate what the review will cover, outlining the purpose and scope.
2. b) Present past work and identify the gaps in the previous work that the findings from the proposed study may shed some light on.
3. d) Add more information to enable readers' understanding of the authors' view.
4. Leave out trivial information.
5. Briefly explain how this work differs from previously published work.
6. State specific objectives and highlight them.
7. Highlight key findings in the conclusions and compare them to other work. In general, expand the discussion in this regard.
8. Remove less important and unrelated or less related references and ensure that all references are cited and arranged in the order required by the journal.
9. Avoid mass citations whenever possible, for example [1-2], [4-5].
Write concisely and avoid repetitive statements. It is also recommended to use more recent studies regarding the scope of the study. You are encouraged to read, for instance, the following papers to get some ideas on using educational technology to cultivate critical thinking regarding the problem statements:
Methodology:
Please clarify the following:
Describe the sampling technique and the data gathering instruments in sufficient detail, e.g.,. Similarly, it would help clarify how the data analysis methods used in the paper are appropriate for analyzing the data obtained.
Discuss the reliability and the validity of the study outcomes. It is also essential to address the study's limitations and comprehensively discuss the expected benefits of the topic discussed in this paper.
Discussion:
The discussion section is done together with the report of the findings. Relevant citations have been selected to support the discussion. However, the discussion of findings was quite briefly written. More elaboration and critical discussion can support the extensive data from the findings.
Author Response
DETAILED RESPONSES TO REVIEWERS’ COMMENTS
The authors are very grateful for valuable comments and suggestions of the editor and reviewers. We have revised the original manuscript in accordance with the comments suggested by the editor and reviewers.
Reviewer1’s comments and replies:
Comment #1:
- a) Include a few introductory lines to indicate what the review will cover, outlining the purpose and scope.
Reply #1:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
The main focus is on the settling index of tailing slurries with a certain starting concentration, calculating and analyzing the change in concentration and volume during the settling process, and finding the minimum time required to approach the final settling index of around 85～100% in order to achieve the purpose of preparing highly concentrated filled slurries.
Comment #2:
- b) Present past work and identify the gaps in the previous work that the findings from the proposed study may shed some light on.
Reply #2:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
In previous tests, researchers have tended to focus too much on the rapid settling of the tailings slurry by adding flocculants to facilitate the settling of the tailings. While this has improved the settling rate of the tailings particles, it has also increased the cost of the tailings concentration and therefore needs to be considered to speed up the settling of the tailings in a cost effective manner so that it can also meet the needs of the filling process at a low cost of operation.
Comment #3:
- d) Add more information to enable readers' understanding of the authors' view.
Reply #3:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Generally, for tailings flocculation and settlement, the amount of flocculant added to make the tailing sand settle to the required concentration for the filling process is 5～25g/t. The commonly used flocculants are polyacrylamide flocculant and Eisen flocculant, of which the price of polyacrylamide is RMB 13,500/t and the price of Eisen flocculant is RMB 16,000/t. The cost of polyacrylamide as a flocculation and sedimentation agent can be calculated as 0.0675～0.3375 RMB/t, and the cost of Eisen flocculant as a flocculation and sedimentation agent is 0.0800～0.4000 RMB/t. For a mine that requires 1 million tons of tailings to be filled annually, the annual cost of chemicals used for flocculation and sedimentation will be as high as 6.75～33.75 million yuan/a or 8.00～40.00 million yuan/a. As flocculant dosing equipment and its ancillary facilities are also necessary facilities, for a single set of dosing equipment, the equipment input is usually 150～35 million yuan per set, which shows that the equipment aspect The investment in equipment is also considerable.
Comment #4:
4.Leave out trivial information.
Reply #4:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
This part has been removed: The tailings used in the subsidence tests conducted in this study were obtained from an ore treatment plant of a mine. Random sampling was carried out at scattered time intervals to ensure that the tailings samples were representative.
Comment #5:
5.Briefly explain how this work differs from previously published work.
Reply #5:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
The difference between this work and previously published work is that too much research has been done on flocculation settling tests to accelerate the settling rate of tailing sand particles by adding flocculants, which is technically feasible but also adds a certain amount of production costs, thus burdening the enterprise. This study focuses on the effect of natural settlement of the tailings and, through relevant experimental tests, identifies technical measures where natural settlement can meet the requirements of the filling process, thus providing the necessary technical basis for the technical solution.
Comment #6:
6.State specific objectives and highlight them.
Reply #6:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
(2) From the natural settling effect of tailing sand in this study, the process of tailing sand settling concentration and tailing sand slurry preparation is well integrated, the tailing sand settling speed is faster in the natural state, the use of natural settling concentration of low concentration tailing sand slurry can save a lot of flocculant costs, thus creating conditions for the continuous preparation of low-cost filling slurry, the rapid natural settling of tailing sand also greatly improves the preparation efficiency of filling system tailing sand storage and pressurized air slurry.
Comment #7:
7.Highlight key findings in the conclusions and compare them to other work. In general, expand the discussion in this regard.
Reply #7:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
(1) Usually the technological process of the backfill system is determined by the properties of the backfill material. From the initial, mid-term and final whole process of the natural sedimentation of tailings particles in this study, it can be seen that the natural settling speed of this iron ore tailing sand is fast, and the total amount of clear water produced can reach 50% of the total final clear water in 5 to 7.25 minutes, Within 10 to 20 minutes, it can approach 95 to 98% of the parameters of the final settlement state.
Comment #8:
8.Remove less important and unrelated or less related references and ensure that all references are cited and arranged in the order required by the journal.
Reply #8:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Some unimportant, or less relevant references have been removed to avoid mass citations. At the same time, the order of the references has also been adjusted. The deleted documents were numbered in the original version as [14]、[15]、[18]、[27]、[28].
Comment #9:
9.Avoid mass citations whenever possible, for example [1-2], [4-5].
Reply #9:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Some unimportant, or less relevant references have been removed to avoid mass citations.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The publication presents the basic measurements in the scope of subsidence of tailings in water, however authors described that "The use of the natural subsidence process for concentration and dehydration of tailings slurry can reduce costs related to the operation of the facility and flocculation agents.". unfortunatelly in this scope no experimental data or economic analysis was presented. it was also indicated the lack of composition of tailings, dissoliution of cpmponents including heave metals in water, study with flocullants. What do the authors think is " clear water", what transparency and how much suspended solids characterise the clear water? Moreover, the Figures 2-4 are not clear, and in Fugure 1 "SiO3" should be corrected to SiO2.
Author Response
DETAILED RESPONSES TO REVIEWERS’ COMMENTS
The authors are very grateful for valuable comments and suggestions of the editor and reviewers. We have revised the original manuscript in accordance with the comments suggested by the editor and reviewers.
Reviewer2’s comments and replies:
Comment #1:
The publication presents the basic measurements in the scope of subsidence of tailings in water, however authors described that "The use of the natural subsidence process for concentration and dehydration of tailings slurry can reduce costs related to the operation of the facility and flocculation agents.". unfortunatelly in this scope no experimental data or economic analysis was presented. it was also indicated the lack of composition of tailings, dissoliution of cpmponents including heave metals in water, study with flocullants.
Reply #1:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Generally, for tailings flocculation and settlement, the amount of flocculant added to make the tailing sand settle to the required concentration for the filling process is 5～25g/t. The commonly used flocculants are polyacrylamide flocculant and Eisen flocculant, of which the price of polyacrylamide is RMB 13,500/t and the price of Eisen flocculant is RMB 16,000/t. The cost of polyacrylamide as a flocculation and sedimentation agent can be calculated as 0.0675～0.3375 RMB/t, and the cost of Eisen flocculant as a flocculation and sedimentation agent is 0.0800～0.4000 RMB/t. For a mine that requires 1 million tons of tailings to be filled annually, the annual cost of chemicals used for flocculation and sedimentation will be as high as 6.75～33.75 million yuan/a or 8.00～40.00 million yuan/a. As flocculant dosing equipment and its ancillary facilities are also necessary facilities, for a single set of dosing equipment, the equipment input is usually 150～35 million yuan per set, which shows that the equipment aspect The investment in equipment is also considerable.
Comment #2:
What do the authors think is " clear water", what transparency and how much suspended solids characterise the clear water? Moreover, the Figures 2-4 are not clear.
Reply #2:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
The "clear water" mentioned here refers to the water in the upper part of the turbid tailings slurry, which has a relatively clear boundary with the turbid slurry. Same below.
Comment #3:
In Fugure 1 "SiO3" should be corrected to SiO2.
Reply #3:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
In figure 1, "SiO3" has been modified to SiO2.
Author Response File: Author Response.pdf
Reviewer 3 Report
Before the article is accepted for publication, the authors must respond to the following comments:
- The abstract must present information about the research objectives and justifications. Please revise this in your next version.
- The keywords are not suitable. Please use 3 to 5 keywords, not expressions.
- The citations in the introduction use a standard of generic references. Instead, use specific references highlighting the information present in each of the references in a specific way. Note line 77. The authors used references [12 – 15] but do not address the specific information in these references. Please correct this in every manuscript.
- Correct the title: 2. Materials and methodS.
- Include figures on the materials used in section 2. This way it is clearer to readers what is being researched.
- It would be important to include additional information about the materials under study, such as the granulometry curve and the mineralogical composition defined by XRD. If possible include this information in your next version.
- I cannot understand what tests were performed and how they were defined. What temperature was used in the test? How many repetitions were performed? Please include more specific information in section 2.3. If possible, include the rules followed in the survey.
- Compare the results obtained in your search with similar ones. Note that in section 3 no references are used. This is not acceptable for a scientific article text. Fix this pattern in your next version.
- Organize the conclusion into smaller topics that highlight only the most relevant aspects of your research.
Author Response
DETAILED RESPONSES TO REVIEWERS’ COMMENTS
The authors are very grateful for valuable comments and suggestions of the editor and reviewers. We have revised the original manuscript in accordance with the comments suggested by the editor and reviewers.
Reviewer3’s comments and replies:
Comment #1:
The abstract must present information about the research objectives and justifications. Please revise this in your next version.
Reply #1:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
In order to provide a technical basis for the subsequent concentration and utilization of the tailings treatment process in an iron ore mine, and to achieve the objectives of cost reduction and sustainable development, the settling concentration and settling capacity of a tailings slurry with an initial concentration of 40% in its natural state were tested in conjunction with the pumping supply concentration index of the beneficiation tailings slurry in a metal mine. The test results show that the iron ore tailings particles settle at an overall fast rate, basically within 10 to 20 min they are able to reach or approach 85 to 99.5% of the final settling state related index, during the settling process in the fixed container, at first the clarified water at the top of the tailings slurry is very turbid, with the passage of time the clarified water gradually becomes blurred and clear from turbidity, and the interface between the slurry and the water gradually becomes clearer. From the phenomena observed during the settling process and the test parameters such as the net increase in clear water and slurry variation, the maximum settling concentration and settling capacity indicators of 50% and 90% can be reached or approached in 5.5 to 7.25min and 10.5 to 15.5min after settling, and the maximum settling concentration and settling capacity can be reached or approached in 10 to 20min after the settling process. As the settling tests and observations continued, the relevant settling parameters basically reached the final settling state within the time period of 20 to 1440min, during which the settling concentration of the tailing sand was 71.33 to 73.42% and the settling capacity was 1.85 to 1.91g/cm³. It can be judged from the test results that the natural settling of the low concentration tailings slurry can meet the technical specifications required for the filling process, and that the natural settling and concentration of dewatering can save the costs of the relevant facilities and flocculation chemicals, and therefore has good technical and economic feasibility.
Comment #2:
The keywords are not suitable. Please use 3 to 5 keywords, not expressions.
Reply #2:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
solid waste utilization; tailings settlement; sustainable development; goaf management; filling materials
Comment #3:
The citations in the introduction use a standard of generic references. Instead, use specific references highlighting the information present in each of the references in a specific way. Note line 77. The authors used references [12 – 15] but do not address the specific information in these references. Please correct this in every manuscript.
Reply #3:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
References [12-15], [16-18], and [25-28] have all been modified, and the modified serial numbers are [12-13], [14-15], and [24-25].
Comment #4:
Correct the title: 2. Materials and methodS.
Reply #4:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
The corresponding headings have been modified.
Comment #5:
Include figures on the materials used in section 2. This way it is clearer to readers what is being researched.
Reply #5:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
The corresponding tailing particle size distribution curve, Fig. 3 Tailing particle size distribution curve, has been increased and adjusted to the second part.
Comment #6:
It would be important to include additional information about the materials under study, such as the granulometry curve and the mineralogical composition defined by XRD. If possible include this information in your next version.
Reply #6:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Particle size determination curves of tailings have been supplemented.
Comment #7:
I cannot understand what tests were performed and how they were defined. What temperature was used in the test? How many repetitions were performed? Please include more specific information in section 2.3. If possible, include the rules followed in the survey.
Reply #7:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
In order to avoid the phenomenon of data dispersion, the experimental test was repeated 3 times, which was used as the basis to study the rules followed by the experiment.
Comment #8:
Compare the results obtained in your search with similar ones. Note that in section 3 no references are used. This is not acceptable for a scientific article text. Fix this pattern in your next version.
Reply #8:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
Similar results have been compared and references [20] and [21] have been introduced.
[20] Badiozamani Mohammad Mahdi and Beier Nicholas. Estimating the Potential Differential Settlement of a Tailings Deposit Based on Consolidation Properties Heterogeneity[J]. Applied Sciences, 2022, 12(12) : 6206-6206.
[21] Xie Jincheng et al. Tailings Settlement Velocity Identification Based on Unsupervised Learning[J]. Metals, 2021, 11(12) : 1903-1903.
Comment #9:
Organize the conclusion into smaller topics that highlight only the most relevant aspects of your research.
Reply #9:
The author is very grateful for the question raised by the reviewer and has explained the following contents in the revised manuscript, which has been shown in blue font in the corresponding revised manuscript.
（1）Usually the technological process of the backfill system is determined by the properties of the backfill material. From the initial, mid-term and final whole process of the natural sedimentation of tailings particles in this study, it can be seen that the natural settling speed of this iron ore tailing sand is fast, and the total amount of clear water produced can reach 50% of the total final clear water in 5 to 7.25 minutes, Within 10 to 20 minutes, it can approach 95 to 98% of the parameters of the final settlement state.
（2）From the natural settling effect of tailing sand in this study, the process of tailing sand settling concentration and tailing sand slurry preparation is well integrated, the tailing sand settling speed is faster in the natural state, the use of natural settling concentration of low concentration tailing sand slurry can save a lot of flocculant costs, thus creating conditions for the continuous preparation of low-cost filling slurry, the rapid natural settling of tailing sand also greatly improves the preparation efficiency of filling system tailing sand storage and pressurized air slurry.
（3）The natural settling test of the tailings slurry in this study shows that the tailings sand particles settle and compress in a relatively short period of time, where the settling trajectory of the tailings sand particles is largely linear and less influenced by water molecules during the downward movement, and the final formation of the tailings slurry has a more uniform particle arrangement with no obvious difference in particle size in the horizontal direction. The maximum settling concentration of the tailing slurry is 72.03% after testing in this research system, therefore, the reference concentration for the preparation of the tailing slurry can be determined to not exceed this limit value, which corresponds to a settling capacity of the tailing slurry of approximately 1.867 g/cm³.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors improved the paper to the accepted version, therefore I recommend the article for publication.
Reviewer 3 Report
The authors responded to all comments from the previous review. Therefore, I recommend the article for publication.
