A Study on the Mechanical Properties and Hydration Process of Slag Cemented Ultrafine Tailings Paste Backfill
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe review of the paper entitled “A Study on Mechanical Properties and Hydration Process of 2 Slag Cemented Ultrafine Tailings Paste Backfill” submitted to the “Sustainability” Journal (sustainability-2914071).
The paper concerns the subject of optimizing the material composition of a slag-cemented ultrafine tailings paste backfill prepared with various cementitious materials (including OPC, slag, and desulfurized gypsum) in the context of basic properties of cementitious building composites. The manuscript presents original research results. The title of the publication as well as the abstract section are adequate to the content. The test procedures are described properly. The results are presented properly. The inference was carried out correctly and summarizes the discussion of the results well and provides an explanation of the results obtained. The manuscript appear to be suitable for publication in its current form after some minor corrections.
Remarks and editorial notes:
1) Please give the numbers and full titles (in English) of standards that describe the characteristics and demands for the used materials the applied test procedures.
2) Table 2 should be “Table 1”, “Table 3” should be “Table 2” – please revise and correct the numbering also in the text of the manuscript.
3) The current “Table 3” - data in the table should be given with the same precision, i.e. values should have the same number of places after the decimal separator.
4) Unnecessary lines No 117, 235
Author Response
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Reviewer 2 Report
Comments and Suggestions for AuthorsIn this manuscript, the slag-gypsum-cement system is employed either as a substitute for the single Portland cement or as the cemented material for ultrafine tailings paste backfill. The manuscript describes the mechanical properties and hydration process of the paste backfill in detail, which has certain reference significance for the solid waste recycling of the mining industry. However, before submission for publication, clarification on certain issues is imperative.
(1) There are many flaws in the format of the manuscript. For example, the standard format in line 109 and 110, the picture annotation in Fig.2(a), the lack of punctuation causing the confused expression of sentence meaning in line 206, the incomplete sentence in line 323, and the inconsistency in the format of multiple headings in line 152 and 236.
(2) The pictures of Fig.7 (a) and (b) were seriously defective, resulting in incomplete information in Table 3, as well as unclear meaning and logic confusion in 3.3. SEM analysis.
(3) The expression of "compressive result" is inaccurate in line 173.
(4) The description of the test method in the manuscript is not comprehensive, and the data are not detailed. According to the standard, the compressive strength test should be based on the average of six compressive strength measurements obtained on a set of three prisms. When one of the six measurements exceeds ±10% of the average, the result should be excluded. The processing method of test results in Fig.5 may not meet the requirements of the standard.
(5) The interpretation and analysis of fluidity in the manuscript is not comprehensive, and the special rules between SCUPB C-1, C-2, C-3 and C-4 are not analyzed. It is recommended to analyze the mechanism of the sudden rise of fluidity with c/g from 2:3 to 1:4.
(6) In contrast to the inert aggregate, mine tailings possess fine particle sizes and reactive properties. It is advisable for the manuscript to offer a straightforward clarification regarding the microactivity exhibited by the ultrafine tailings as discussed in the analysis of Fig.8.
(7) There exists a significant cost variance among slag, desulfurized gypsum, and cement. Desulfurized gypsum as an industrial by-product, offers environmental advantages when compared to Portland cement. It is recommended that a preliminary evaluation of SCUPB with various mix proportion should be carried out based on economic benefit and carbon emission.
(8) The manuscript lacks coherence due to scattered discussion of results, necessitating a revision of the chapter structure to enhance logical flow and consistency.
(9) In the conclusion section, clearly state the main discovery and practical implications of the research. In addition, it is recommended to discuss the limitations of the research and the direction of future research.
The above content only provides reference for the author to revise and enrich the manuscript. Please make appropriate adjustments and improvements based on the actual research.
Comments on the Quality of English LanguagePlease consider to polish your language.
Author Response
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Reviewer 3 Report
Comments and Suggestions for Authors1. Abstract: It is not clear what the authors aim to achieve with this work. It is recommended to be more explicit.
2. Abstract: it is not clear what the authors mean by "desulphurised gypsum". Please explain.
3. Abstract: The age of the tests to determine the mechanical compressive strength is not specified. Nor is it specified at what age the initial strengths were obtained. Explain.
4. Abstract: How much gypsum was used?
5. Abstract: it is not clear what the authors mean in the following sentence on Line 26: "...the combined activation of slag by cement and desulphurized...".
6. Abstract: it is recommended to delete the word deep in Line 29.
7. Abstract: it is recommended to add a paragraph at the end of the abstract highlighting in which specific fields of science and/or technology the results obtained in this research could be applied.
8. What is the calculated water/cement ratio for this study?
9. Line 87: there is a possible error in the word "uesd" (Line 87). Perhaps the authors meant to say "used". Fix.
10. Section 2. Authors are encouraged to write "Materials and Methods" instead of "Experimental programs". Fix.
11. Line 104. The authors write: "...and a desulphurization gypsum...". This sentence does not seem to make sense. Elsewhere in the manuscript it is written differently. Please correct.
12. Lines 102, 103, 109 and 111. The authors use the following nomenclatures: GB/T 18046-2017; GB175-2007; GB/T203-2008; GB/T18046-2017... Are they standards? If so, then they should be referenced in the References Section.
13. Section 3. It is recommended to rename it simply as "Results".
14. Subsection 3.1. Figure 4 should not be placed directly after the title; a paragraph should be placed between the two.
15. Figure 6. The authors only point out the points where micro-fractures have occurred, which is of secondary importance, as these micro-cracks could have formed due to the effect of the mechanical strength test. Instead, it would be more logical to use abbreviations to indicate the names of the mineral species formed, such as ettringite and portlandite.
16. Figure 7. The same recommendation is made as for Figure 6.
17. Lines 139 and 140. The authors do not specify whether GB/T17671 and GB/T50448 are standards. Please note that if they are, they need to be listed in the References Section.
18. Subsection 3.2. Authors are urged that Figures and tables cannot be placed directly below the section title. Fix throughout the manuscript.
Comments on the Quality of English LanguageGrammar, writing and spelling should be checked in detail.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript has been modified in accordance with the previous recommendations, but the following issues still exist.
(1) There are still formatting flaws in lines 275 and 328 of the manuscript.
(2) The manuscript lacks data and evidence for the sections on economic benefit and carbon emission analysis.
(3) After modification, the compressive strength results meet the requirements and are relatively comprehensive. However, the experimental data is not sufficiently specific.
(4) The analysis of microactivity of ultrafine tailings is redundant and fails to focus on the crucial aspects.
The manuscript is generally comprehensive but still has some issues with regard to details.
Minor editing of English language required
Author Response
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Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors have answered the questions posed and have made the modifications indicated in the review process.
Author Response
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Author Response File: Author Response.pdf
