Measuring Ultrasonic and Electrical Properties of Early-Age Cemented Tailings Backfill
Round 1
Reviewer 1 Report
This manuscript aims to investigate the feasibility of using ultrasonic wave transmission and electrical conductivity method to describe the setting behavior of CTB. This topic will be interesting for the backfill mining specialist and technologists. However, the following comments should be addressed before the acceptance of this manuscript.
1. How did you obtain the physical properties of the tailings shown in Figure 1?
2. Figure 4，page 4，how are the three stages divided into, and what is based on?
3. It is better to unify the decimals in the quantitative values along the manuscript specifically in the tables and results.
4. Figure 13, page 11, it is good to illustrate the setting process by figure, but the digital expression is also necessary, it would be fantastic if you can add the specific time tested by ultrasonic wave and electrical conductivity in a table.
5. In Introduction section, the authors should add some latest reference like “Compressive fatigue behavior and failure evolution of additive fiber-reinforced cemented tailings composites. International Journal of Minerals Metallurgy and Materials.2022, 29, 345-355 and Characterization of Macro Mechanical Properties and Microstructures of Cement-Based Composites Prepared from Fly Ash, Gypsum and Steel Slag. Minerals.2022, 12, 6. ”
Author Response
We sincerely thank the reviewers for their comments, which have helped us better identify the scope of our work and also clarify a few points. Below are our responses to academic editor's comments point-by-point. The replies are highlighted in BLUE. And the suggested comments have been revised and added in Red font in the revised manuscript.
Reviewer 2 Report
This article introduces a non-destructive assessment of the early age properties of CTBs, which is an interesting and practically applicable technique. The choice of simple measurement techniques like UPV and resistivity would be really helpful to assess the setting process of CTBs. The article is written clearly, and minor revisions are required before its finalization for publication:
1) The abstract misses the main objective or aim of this research.
2) Include a short statement about the environmental and engineering significance of CTBs in abstract.
3) What parameters were considered for CTB preparation.?
4) Research significance and problem statements are not strong in the introduction. What would be the possible best benefits or outcomes of this study should be briefly included in the manuscript.
5) Mix design must be included in a table.
6) What standards were followed for EC?
7) UPV test is presented with too many details. Avoid complex or verbose methodology sections.
8) L160-180: The bullet points under the discussion section are not appropriate.
9) Conclusion section should have introductory (explaining briefly about the studied parameters) paragraph before bullet points.
This innovative research deserved publication in materials journal after these minor revisions.
Author Response
We sincerely thank the reviewers for their comments, which have helped us better identify the scope of our work and also clarify a few points. Below are our responses to academic editor's comments point-by-point. The replies are highlighted in BLUE. And the suggested comments have been revised and added in Red font in the revised manuscript.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Dear Authors, Firstly, I need to apologize for taking all of my time credits and a short delay. December is always a busy month and seems not to be a good time to accept any additional duties. Anyway, I read this work with pleasure and I believe that after some corrections and adjustments, it could be published in quality journal. I have, however, some doubts and general comments listed below:
1. Just an editorial issue - your reference list is not formatted according to MDPI template. I appreciate your diversity of cited documents form various countries and testing traditions.
2. Your description of CTB application and need for fast and reliable testing methods in the Introductory part is rather short and does not cover all important issues (getting rid of spoil material on surface, increasing stability and safety of mining activities, possible reduction and/or substitution of Portland cement). Well, I understand that it is Authors privilege and responsibility to choose the range of references but I'd like to encourage you to make additional research in Scopus or MDPI (open access) database for relevant references concerning backfill materials and its transportation (at early stage after mixing). I know some works of Russian Authors from MISiS (Kongar-Syuryun, Adigamov). I also know some Polish works by Jendrysik and Kanty from MENARD company who worked on non-standard cement composites. Please do not consider my Authors suggestion as mandatory, I only want to encourage you to make your own search.
3. Concerning figures 3-7. If you group charts (diagrams) presenting same issues, please try to provide same range of values on vertical and horizontal graph axes. It makes it much easier to understand the range of presented values.
4. The entire research seems to be ok. I'd appreciate some more modest conclusions. You seem to draw strong statements from limited data under study. Maybe, some reservations and recommendations for further research would solve this problem.
Best regards
Author Response
We sincerely thank the reviewers for their comments, which have helped us better identify the scope of our work and also clarify a few points. Below are our responses to academic editor's comments point-by-point. The replies are highlighted in BLUE. And the suggested comments have been revised and added in Red font in the revised manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
Dear Authors
I liked your study in course of my first evaluation and I still like it now.
I noticed that you considered my editorial comments and you made some statements concerning my major concerns.
I believe that the paper may be published "as it is now".
I think, however, that if you have time and opportunity, it would be profitable to highlight (underline) the practical outcomes that may be derived from your findings. Just 2-3 lines in the Conclusions, informing the Reader, what benefits are related to possible use of various taillings. Just to prove that your research program is motivated deeper than just by scientist's curiosity.
Best regards and good luck
