Fiber-Reinforced Coal Gangue-Based Alumina Aerogel Composites with Highly Thermal Stability by Ambient Pressure Drying
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe topic of this paper is the creation of an aerogel composite based on coal gangue using an ambient pressure drying method. Coal gangue is the low-carbon rock and is often discharged as solid waste. It occupies a large amount of land resources while being prone to spontaneous combustion release of toxic and harmful gases. Therefore, it is necessary to utilize coal waste to prevent severe environment pollution. The effective treatment and utilization of coal gangue cannot only realize the green development of coal industry but also realize the recycling of secondary resources.
Aerogel is a light porous solid material, which has a lot of very good characteristics and properties, such as low density, very high specific surface area, high porosity and low thermal conductivity, which makes it extremely useful for insulation applications. However, production of aerogel is limited due to expensive precursors and complex processing. Utilizing coal gangue to create aerogel materials, specifically aluminum based has the potential to significantly lessen and render harmless the solid waste coal gangue.
Coal-gangue based composite aerogel obtained by the authors has similar low-density (0.26 g/cm3) and low thermal conductivity (0.047 W/m*K) at room temperature compared to the supercritical standard dried fiber/aerogel material. It should be noted that the thermal conductivity remained low after heat treatment at 1200 C for 2h.
This paper is of great practical relevance, particularly because the work creates a low-cost solid waste-based aerogel composite that is as good as standard aerogel composites. In addition, the use of solid waste, in this case coal gangue, has the potential to improve the utilization efficiency of this product, thereby reducing environmental pollution. Some explanations of physical background of the described phenomena would be beneficial for the potential reader.
Comments on the Quality of English LanguageThe topic of this paper is the creation of an aerogel composite based on coal gangue using an ambient pressure drying method. Coal gangue is the low-carbon rock and is often discharged as solid waste. It occupies a large amount of land resources while being prone to spontaneous combustion release of toxic and harmful gases. Therefore, it is necessary to utilize coal waste to prevent severe environment pollution. The effective treatment and utilization of coal gangue cannot only realize the green development of coal industry but also realize the recycling of secondary resources.
Aerogel is a light porous solid material, which has a lot of very good characteristics and properties, such as low density, very high specific surface area, high porosity and low thermal conductivity, which makes it extremely useful for insulation applications. However, production of aerogel is limited due to expensive precursors and complex processing. Utilizing coal gangue to create aerogel materials, specifically aluminum based has the potential to significantly lessen and render harmless the solid waste coal gangue.
Coal-gangue based composite aerogel obtained by the authors has similar low-density (0.26 g/cm3) and low thermal conductivity (0.047 W/m*K) at room temperature compared to the supercritical standard dried fiber/aerogel material. It should be noted that the thermal conductivity remained low after heat treatment at 1200 C for 2h.
This paper is of great practical relevance, particularly because the work creates a low-cost solid waste-based aerogel composite that is as good as standard aerogel composites. In addition, the use of solid waste, in this case coal gangue, has the potential to improve the utilization efficiency of this product, thereby reducing environmental pollution. Some explanations of physical background of the described phenomena would be beneficial for the potential reader.
Author Response
Thank you very much for your comments and suggestions. We appreciate your earnest work and hope that the correction will meet with approval. I look forward to hearing from you. Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsDear authors,
please make 2. Materials and Methods.
Now in "2. Experimental Procedures" are not so many details about Materials and Methodology. You give one scheme and schor describing.
No comment after Fig.1.
"Preprstion" also needs more details.
Table 1. please, give the range for each component.
In Table 1 we can see 51.72% about SiO2, please add references about SIO2.
For example review
Karlina, A.I., Karlina, Y.I., Gladkikh, V.A. Analysis of Experience in the Use of Micro- and Nanoadditives from Silicon Production Waste in Concrete Technologies // Minerals, 2023, 13(12), 1525
3.2.1. Needs some theoretical information.
More analysis after fig.2.
Discussion is too short.
No conclusions?
Best regards, reviewer
Author Response
Thank you very much for your comments and suggestions. We appreciate your earnest work and hope that the correction will meet with approval. I look forward to hearing from you. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript "Fiber-Reinforced Coal Gangue-Based Alumina Aerogel Composites with Highly Thermal Stability by Ambient Pressure Drying" contains several inaccuracies that need to be corrected. There is no information on the statistical parameters of the samples tested in subsequent tests. This needs clarification and correction in the article.
General remarks
1. In Chapter 2.3, it should be stated whether the test methodologies for the bulk density, the volume shrinkage, DSC-TG, and the thermal conductivity are consistent with the relevant standards.
2. It is necessary to determine how many ASF/AA samples were prepared for individual tests and whether statistical parameters in the form of standard deviation SD and coefficient of variation COV were determined.
3. Applications should be supplemented with a statistical evaluation of the research.
Specific remarks
4. 12 line: It is necessary to explain what exactly the APD abbreviation means.
5. 46 line: It is necessary to explain what exactly the abbreviation SCFD means.
6. 51-53 lines: The authors repeated the same sentence. This needs to be changed.
7. 157 line: The meaning of "Firing vector of CG" should be explained in the text.
8. 189 line: Please write: XRD pattern of CG before and after calcination at the optimal temperature.
9. 280 line: Please explain what "After" means.
10. 372 line: The title of the chapter should be changed to "Conclusions".
11. 373-387 lines: Conclusions should be bulleted.
I recommend an in-depth review of the manuscript, including comments, to make it an article suitable for publication in the Sustainability.
In its current state, the article should not be published.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
Thank you very much for your comments and suggestions. We appreciate your earnest work and hope that the correction will meet with approval. I look forward to hearing from you. Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for Authors-
Author Response
Thank you very much for your comments and suggestions. We appreciate your earnest work and hope that the correction will meet with approval. I look forward to hearing from you. Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsCompared to the previous version of the article, they have introduced corrections that partially take into account the reviewer's suggestions. However, there are still serious inaccuracies that require necessary correction.
Determining the statistical parameters of the standard deviation SD and the coefficient of variation COV is necessary due to the assessment of the quality of research and materials for each study separately. It is a misunderstanding to compare ICOV SD parameters for studies that are so diverse. This needs to be changed.
The article may be published after taking into account the above comments.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
Thank you very much for your comments and suggestions. We appreciate your earnest work and hope that the correction will meet with approval. I look forward to hearing from you. Please see the attachment.
Author Response File: Author Response.pdf
