Development of a Molding Mixture for the Production of Large-Sized Casting Molds
, Aristotel Issagulov 1, Pavel Kovalev 2, Svetlana Kvon 1,*, Igor Matveev 2 and Saniya Arinova 1Round 1
Reviewer 1 Report
Comments and Suggestions for Authors- ​​The quantitative relationship curve between quartz powder content and sedimentation stability was not presented, with only a description.
- ​​Figure 9 compares defects across different processes but lacks specific numerical scales, making it difficult to visually assess their relative superiority.
- ​​ ​​Although the hardened structure comparison is shown (Figure 4), XRD/SEM analysis of hydration product morphology and phase composition was not conducted."​​ ​
- The key chemical reaction pathways, such as sodium aluminate promoting 'rapid ettringite nucleation,' were not discussed in depth.
- ​​Regarding sedimentation stability evaluation, only visual observation was relied upon, without quantitative data from turbidimeters or sedimentation balances.
- Among 22 cited references, only 5 were published in recent five years, potentially overlooking the latest research advancements.
Not Applicable
Author Response
Response to Reviewer 1 Comments
Thank you very much for taking the time to review the answers to the previous round of checks. We hope that we have responded appropriately to your comments.
Comments 1: The quantitative relationship curve between quartz powder content and sedimentation stability was not presented, with only a description.
Response 1:
The observation was visual. In this study, sedimentation stability was visually evaluated based on the time at which a clear boundary appeared between the sediment and the liquid phase. This method does not contradict the measurement procedure.
Comments 2: Figure 9 compares defects across different processes but lacks specific numerical scales, making it difficult to visually assess their relative superiority.
Response 2: The numerical scale is not critical in this case, as the presence of any defect within the casting body is considered unacceptable. The solidification modeling demonstrated that when using the Alfa-set process and cement-based molds, shrinkage cavities were relocated to the risers. In all other cases, shrinkage cavities remain within the casting body. This is clearly visible in the figure, where red spots inside the casting indicate defects. The risers are represented by three cylinders located on the surface of the casting.
Comments 3: Although the hardened structure comparison is shown (Figure 4), XRD/SEM analysis of hydration product morphology and phase composition was not conducted."​​ ​
Response 3: We agree with the reviewer that such studies are essential for understanding the strengthening mechanism. This study represents the initial stage of a broader investigation, the results of which will determine the direction of future experiments. X-ray structural analysis of the morphology and phase composition of the hydration products is planned for the next stage of the research.
Comments 4: The key chemical reaction pathways, such as sodium aluminate promoting 'rapid ettringite nucleation,' were not discussed in depth.
Response 4: Sodium aluminate is a strong coagulant and promotes the hydration process of concrete. During hydration, it binds fine particles into larger ones, whose size exceeds the critical nucleation threshold. As a result, these coagulated particles act as crystallization centers, thereby accelerating the hardening process of concrete.
However, this topic is a subject for further investigation and was not studied in detail in the present study.
Comments 5: Regarding sedimentation stability evaluation, only visual observation was relied upon, without quantitative data from turbidimeters or sedimentation balances.
Response 5: Only visual observation was used in this study, as stated in the “Materials and Methods” section.
Comments 6: Among 22 cited references, only 5 were published in recent five years, potentially overlooking the latest research advancements.
Response 6: I agree. According to my knowledge, no similar studies have been conducted in the past five years.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors“ complex alloyed steels” – this is too general – please be specific which grade is talking
“The study presented in [11] examines samples..” which is the issue or benefit from this study and why was disused ?
Line 57-68 are bullet point- this is not a final year thesis rather it should be an depth review of literature
The objective is clear however it is unclear which is the scientific novelty
Why this grade was selected “Portland cement grade PC-400”
“stainless steel or plastic”- firstly which grade? Secondly the cone manufactured from metal has some advantages and weakness and the same plastic one. The later should be motivated better why selecting one or another
“GOST 1581-96”- it requires a reference. The same for other standards listed in this work
Standard deviation are required for figure 2 , 5
How was detected the critical level in figure 2
“However, visual observations indicated that increasing” – is there evidence for this ?
Table 3 line that contain sodium aluminate contain a typo after 5 , probably is the letter in Russian ? it should be English one
It was claimed “Without a setting accelerator, the mixture reaches this strength 165 only after 7 days.” But no evidence in figure 3
Figure 4 requires scale bar
As indicated in Figure 7 the calcination is not beneficial – why to use it ?
Figure 9 is interesting but it requires some scale bar, also the boundary condition and loading is required
A section of discussion and interpretation of results is required
Comments on the Quality of English Language
The English could be improved to more clearly express the research.
Author Response
Response to Reviewer 2 Comments
Thank you very much for taking the time to review the answers to the previous round of checks. We hope that we have responded appropriately to your comments.
Comments 1: “ complex alloyed steels” – this is too general – please be specific which grade is talking
Response 1: Complex alloyed steels are iron-based alloys intentionally alloyed with elements such as chromium, nickel, molybdenum, vanadium, and others. These additions impart special properties that distinguish them from plain carbon steels.
However, the focus of this study is on molding mixtures used for casting, particularly those incorporating Portland cement. The presence of Portland cement in the mold mixture increases its strength, making it suitable for producing large-sized castings. Such castings are typically made from complex alloyed steels such as 40CrNi3MoV. Therefore, the term was initially used in the title to reflect the typical application area. The title of the article has been revised to exclude this term, as it is not of principal importance.
Comments 2: “The study presented in [11] examines samples..” which is the issue or benefit from this study and why was disused ?
Response 2: Corrected.
Comments 3: Line 57-68 are bullet point- this is not a final year thesis rather it should be an depth review of literature
Response 3: We agree with the reviewer’s comment. The introduction has been expanded to include a more detailed and comprehensive literature review on the subject.
Comments 4: The objective is clear however it is unclear which is the scientific novelty
Response 4: The objective of the study is to investigate the use of semi-permanent molds in casting production and to assess their feasibility during the metal pouring process. As stated earlier in the manuscript, cement-based molds and their applications have not been thoroughly studied.
The scientific novelty lies in determining the relationships between the flowability of experimental mixtures over time and the amount of accelerator (sodium aluminate and aluminum nitrate) on the hardening rate and strength. Based on these relationships, an optimal mixture composition and curing parameters were identified, ensuring the highest mold strength.
Comments 5: Why this grade was selected “Portland cement grade PC-400”
Response 5: The advantages of Portland cements, which justify their use particularly for large and caisson molds, include low cost, environmental and sanitary safety, and satisfactory technological properties, including heat resistance.
Comments 6: “stainless steel or plastic”- firstly which grade? Secondly the cone manufactured from metal has some advantages and weakness and the same plastic one. The later should be motivated better why selecting one or another
Response 6: According to GOST 26798, the material for manufacturing the cone is not specifically defined; recommended materials include stainless steel or plastic. The important parameter is the cone’s weight, which should be at least 300 grams. Stainless steel cones are more commonly used due to their greater durability, and such a cone was employed in this study.
Comments 7: “GOST 1581-96”- it requires a reference. The same for other standards listed in this work
Response 7: National Standard of the Russian Federation: official edition. Approved and put into effect on October 1, 1998, as a state standard of the Russian Federation by the resolution of the State Construction Committee of Russia (Gosstroy) dated April 10, 1998, No. 18-32. Developed by the Russian State Cement Concern, Cemiskon company, Research Institute of Cement (NIICement JSC), and Drilling Scientific Research and Design Institute (VNIINeft) of the Russian Federation. — Moscow: MNTKS, 1998. — 22 pages. Available at: https://gost-lab.com/uploads/files/gosts/-26798.1-96.pdf
GOST 1581-96. Well Portland Cements. Specifications.
National Standard of the Russian Federation: official edition. Approved and put into effect on October 1, 1998, as a state standard of the Russian Federation by the resolution of the State Construction Committee of Russia (Gosstroy) dated April 10, 1998, No. 18-31. Developed by the Russian State Cement Concern, Cemiskon company, Research Institute of Cement (NIICement JSC), and Drilling Scientific Research and Design Institute (VNIINeft) of the Russian Federation. — Moscow: MNTKS, 1998. — 7 pages.
Comments 8: Standard deviation are required for figure 2 , 5
Response 8: Corrected
Comments 9: How was detected the critical level in figure 2
Response 9: According to GOST 1581-96, cement slurry is considered pumpable if its flowability reaches 150 mm. This condition is stated in the manuscript and highlighted in yellow.
Comments 10: “However, visual observations indicated that increasing” – is there evidence for this ?
Response 10: The observation was visual. In this study, sedimentation stability was assessed visually by measuring the time until a clear boundary appeared between the sediment and the liquid phase. This method is consistent with the measurement procedure and does not contradict it.
Comments 11: Table 3 line that contain sodium aluminate contain a typo after 5 , probably is the letter in Russian ? it should be English one
Response 11: Corrected and highlighted in the text.
Comments 12: It was claimed “Without a setting accelerator, the mixture reaches this strength 165 only after 7 days.” But no evidence in figure 3
Response 12: This is literature data. The source reference has been provided and highlighted in the text.
Comments 13: Figure 4 requires scale bar
Response 13: Corrected.
Comments 14: As indicated in Figure 7 the calcination is not beneficial – why to use it ?
Response 14: These are laboratory studies aimed at determining the optimal compositions.
Calcination in this case simulates the heating process of the mold after metal pouring. During metal pouring, the mold temperature changes, which can cause cracking, further dehydration, and other effects. All these processes lead to a reduction in strength, which is undesirable but inevitable. To assess the extent of strength reduction due to these processes, strength tests after calcination were performed.
These clarifications have been added to the manuscript and highlighted.
Comments 15: Figure 9 is interesting but it requires some scale bar, also the boundary condition and loading is required
Response 15: The simulation was performed on a part measuring 250 by 400 mm.
Boundary conditions were the same across all modeling variants. This aspect is not the focus of the current study.
Comments 16: A section of discussion and interpretation of results is required
Response 16: Section 3 contains both the results and their discussion. The authors considered it methodologically more appropriate to combine these two sections, as this work does not include a significant theoretical part and is focused exclusively on the analysis of the experimental data obtained. The Conclusion section has been slightly expanded accordingly and highlighted in the manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe revision may be suitable for publishing now.
Reviewer 2 Report
Comments and Suggestions for Authors.
Comments on the Quality of English LanguageThe English could be improved to more clearly express the research.
