A Review of the Impact of Spontaneous Combustion on Slope Stability in Coal Mine Waste Dumps

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript is a review article focusing on spontaneous combustion in coal mine waste dumps. Some suggestions are provided below.

(1) It is recommended that the authors revise the title to be more specific about coal mines, as spontaneous combustion is generally not an issue in waste dumps from other types of mines (e.g., metal mines).

(2) Please check the references formatting. E.g. Line 914 and 918–920.

(3) As this is a review article, all data presented should be properly referenced. E.g. Line 158 Table 1

(4) Figure 3 should be improved. It is suggested that the authors redraw the schematic figure themselves to enhance the quality and clarity of the figure.

(5) There are several minor errors throughout the manuscript. Please carefully read through the manuscript and correct all grammatical errors.

• Line 29: "550 million Mg"
• Line 268: "clays or tills"
• Line 294: "the US, Indie"
• Line 389: "environmentn"
• Line 393: "the mi mine"

(6) In Chapter 4.2 Mitigation Strategies, the authors present mitigation approaches categorized by country. It is suggested that this section be reorganized based on different types of mitigation methods rather than by country, as most general mitigation strategies are similar across different countries.

(7) The title of this manuscript is " Impact of Spontaneous Combustion on Slope Stability in Mine Waste Dumps". However, Chapter 5 mainly discusses potential research gaps, which is not directly related to the manuscript’s title. Furthermore, in a review article, a separate "Discussion" chapter is generally unnecessary since no new experimental results are being presented. It is recommended that the authors reorganize the manuscript and integrate relevant parts of the discussion into the corresponding sections above.

Author Response

Dear Reviewer,

I thank you very much for giving me an opportunity to revise my manuscript. I am grateful to your constructive comments and suggestions on my manuscript. I have revised my manuscript according to the comments from you. The main corrections to the paper and my responses to you are as follows:

This manuscript is a review article focusing on spontaneous combustion in coal mine waste dumps. Some suggestions are provided below.

(1) It is recommended that the authors revise the title to be more specific about coal mines, as spontaneous combustion is generally not an issue in waste dumps from other types of mines (e.g., metal mines).

Response: Agreed. Spontaneous combustion is generally a concern in coal mine waste dumps due to the flammable nature of coal. Based on your suggestion, the title has been revised to: A Review of the Impact of Spontaneous Combustion on Slope Stability in Coal Mine Waste Dumps

(2) Please check the references formatting. E.g. Line 914 and 918–920.

Response: References have been reformatted

(3) As this is a review article, all data presented should be properly referenced. E.g. Line 158 Table 1

Response: The data presented in Table 1 are my own. A slope stability analysis was conducted for coal mine waste in Poland. The full analysis can be provided upon request.

(4) Figure 3 should be improved. It is suggested that the authors redraw the schematic figure themselves to enhance the quality and clarity of the figure.

Response: The text in Figure 3 has been improved

(5) There are several minor errors throughout the manuscript. Please carefully read through the manuscript and correct all grammatical errors.

• Line 29: "550 million Mg"
• Line 268: "clays or tills"
• Line 294: "the US, Indie"

Response: I believe all the statements are correctly written, but please feel free to correct me if I'm mistaken.

• Line 389: "environmentn"
• Line 393: "the mi mine"

Response: Agreed. All corrections have been made.

(6) In Chapter 4.2 Mitigation Strategies, the authors present mitigation approaches categorized by country. It is suggested that this section be reorganized based on different types of mitigation methods rather than by country, as most general mitigation strategies are similar across different countries.

Response: General mitigation strategies may appear unrealistic due to the significant differences in geo-mining conditions across countries. While the fundamental theory behind controlling spontaneous combustion involves eliminating at least one of the three essential components—fuel, heat, or oxygen. In practice, the implementation of this concept varies widely. Each country often develops its own specific methods and modifications, matched to local field conditions, mining practices, and environmental regulations.

For this reason, I would prefer to retain this chapter in its current form, as it offers a more targeted and practical perspective for readers, reflecting region-specific challenges and solutions.

(7) The title of this manuscript is " Impact of Spontaneous Combustion on Slope Stability in Mine Waste Dumps". However, Chapter 5 mainly discusses potential research gaps, which is not directly related to the manuscript’s title. Furthermore, in a review article, a separate "Discussion" chapter is generally unnecessary since no new experimental results are being presented. It is recommended that the authors reorganize the manuscript and integrate relevant parts of the discussion into the corresponding sections above.

Response: Spontaneous combustion is a topic that has been widely studied, with most research focusing on environmental influences such as gas emissions, air pollution, and fire hazards. However, its impact on slope stability has received limited attention. Despite numerous reported cases of mine waste dump landslides around the world, the relationship between spontaneous combustion and dump instability remains underexplored. The thermal effects resulting from spontaneous combustion are well-recognized and can significantly alter the geotechnical behavior of mine waste materials. As mine waste dumps continue to grow in size and height, the risk of large-scale landslides may increase. Nevertheless, few studies have specifically investigated this aspect.

Chapter 5 aims to highlight these research gaps by discussing the potential influence of spontaneous combustion and its associated triggering factors on the slope stability of mine waste dumps. Although the chapter does not present new experimental or analytical results, it offers my own evaluation of the current state of knowledge, technological developments, and mitigation strategies related to spontaneous combustion. It also explores the implications these phenomena may have for slope stability in the context of evolving mining practices and environmental regulations.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

It's a review article where fairly extensive research has been done on mine waste dump stability. After reading your article, I have the following observations to make:

1) Most references in the text are to coal waste deposits, perhaps the title should be amended.

2) Lines 54-55: It will better to seperate citations by country or region.

3) For the group citations it will be better to analyse the most important in the text.

4)  Table 1: Better to replace "No cracks/fractures" with "Without cracks/fractures". For a moment I thought that No stood for number.

5)  Figure 5: Reference from which mine is the used photo?

6) Section 4 needs rephrasing; most of the text in this section was marked by the Turnitin similarity report.

 

 

Author Response

Dear Reviewer,

I thank you very much for giving me an opportunity to revise my manuscript. I am grateful to your constructive comments and suggestions on my manuscript. I have revised my manuscript according to the comments from you. The main corrections to the paper and my responses to you are as follows:

It's a review article where fairly extensive research has been done on mine waste dump stability. After reading your article, I have the following observations to make:

1) Most references in the text are to coal waste deposits, perhaps the title should be amended.

Response: Agreed. Spontaneous combustion is generally an issue in coal mine waste dumps due to the flammable characteristics of coal. Based on your suggestion, the title has been modified to: A Review of the Impact of Spontaneous Combustion on Slope Stability in Coal Mine Waste Dumps

2) Lines 54-55: It will better to seperate citations by country or region.

Response: It has been revised as suggested.

3) For the group citations it will be better to analyse the most important in the text.

Response: I believe there may be a misunderstanding. My intention is to review all existing research on a specific topic. I do not consider some studies to be more important than others—each contributes valuable insights. That is why I have cited all the relevant work I found, in order to provide a comprehensive and balanced overview of the current state of knowledge.

4)  Table 1: Better to replace "No cracks/fractures" with "Without cracks/fractures". For a moment I thought that No stood for number.

Response: Agreed. The correction has been incorporated into the manuscript.

5)  Figure 5: Reference from which mine is the used photo?

Response: The mine authority requested that its name not be published. For your information, the mine in question is Marcel Coal Mine. Figures 2, 4, and 5 are my own photographs.

6) Section 4 needs rephrasing; most of the text in this section was marked by the Turnitin similarity report.

Response: Please be aware that this is a review paper, which is primarily based on previously conducted research worldwide. Therefore, some wording and sentences may appear similar to existing sources. Nonetheless, thank you for your note, I have reduced the similarity.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Issue 1. The manuscript titled “A Review of the Impact of Spontaneous Combustion on Slope Stability in Mine Waste Dumps” addresses a relevant and timely topic; however, the article requires substantial revisions before it can be considered for publication. While the paper provides an extensive collection of literature references, the structure, clarity, and scientific rigor must be significantly improved. Below are detailed comments and suggestions for improvement:

 

Issue 2. The abstract is overloaded with general statements and fails to clearly outline the novel contribution of the review. It should succinctly describe the scope, methodology, and key findings or perspectives.

 

Issue 3. In the start of the paper add 1-2 sentences on how historical mining practices contributed to the current volume and distribution of waste.

 

Issue 4. Lines 42-45. Add some actual cases, consider citing ref. doi:10.33271/mining18.04.139 in what metal pollution of water within the mining-industrial region bordered to Poland is investigated and discussed. Also consider citing ref. doi:10.51301/ejsu.2022.i6.06 to emphasize the importance of sustainable waste and tailings management.

 

 

Issue 6. Section 2 ("Mechanisms of Spontaneous Combustion") lacks a clear thematic progression. The description of the four phases (lines 82-86) is useful, but the structure would benefit from numbered subheadings (2.1 Induction phase) for each phase, along with clearer differentiation between processes like oxidation, thermal accumulation, and ignition thresholds.

 

Issue 7. Some sections blend review and original commentary without clarification. For instance, Figure 2 (line 71) is presented as documentation of an actual slope failure in Poland, yet no source is cited, and no details on the study or data collection are provided. Is this a case study or simply an illustrative example?

 

Issue 8. While the article compiles various references, no critical evaluation or comparison of findings is provided. For instance, Table 1 (line 158) presents Factor of Safety (FoS) values, but the method of analysis, assumptions, and validation are not discussed. What model was used? What software? Is it based on published data or the authors’ calculation?

 

Issue 9. The authors claim (line 341): /Most existing studies tend to treat thermal and mechanical phenomena in isolation.../ yet no systematic table or summary of these studies is provided to support this claim. A comparative matrix summarizing literature on thermal effects, slope failures, and monitoring would strengthen this point.

 

Issue 10. Many of the cited studies are outdated or duplicated. For example, multiple entries from Polish institutions could be synthesized to avoid redundancy.

 

Issue 11. Figures 4 and 5 are referenced in the text but lack sufficient explanation or proper labeling. For example, Figure 4 shows slope cracks but does not specify the location, time of observation, or instrumentation used.

 

Issue 12. Figure 6 (city/local heating system configuration) is conceptually interesting but highly speculative and undeveloped. No thermodynamic or engineering feasibility is discussed, nor is there reference to similar systems in practice.

 

Issue 13. The suggestion to use spontaneous combustion as a heat source (line 442) lacks a feasibility study or energy balance analysis.

 

Issue 5. In the discussion contrast Polish waste accumulation with that of other major coal-producing countries (China, Germany, Ukraine) in the context of ESG strategy to contextualize scale and urgency (doi:10.33271/mining17.01.001; etc)

 

 

Issue 14. The Conclusion simply repeats content from earlier sections. It should instead summarize key insights, unresolved questions, and practical implications.

 

Issue 15. The manuscript addresses an important problem but requires significant improvements. With substantial revisions and clearer focus, the manuscript may become suitable for publication.

Author Response

Dear Reviewer,

I thank you very much for giving me an opportunity to revise my manuscript. I am grateful to your constructive comments and suggestions on my manuscript. I have revised my manuscript according to the comments from you. The main corrections to the paper and my responses to you are as follows:

Issue 1. The manuscript titled “A Review of the Impact of Spontaneous Combustion on Slope Stability in Mine Waste Dumps” addresses a relevant and timely topic; however, the article requires substantial revisions before it can be considered for publication. While the paper provides an extensive collection of literature references, the structure, clarity, and scientific rigor must be significantly improved. Below are detailed comments and suggestions for improvement:

Issue 2. The abstract is overloaded with general statements and fails to clearly outline the novel contribution of the review. It should succinctly describe the scope, methodology, and key findings or perspectives.

Response: The abstract provides a concise overview of the review’s scope, the methodology employed in synthesizing existing research, and the key findings and perspectives regarding spontaneous combustion and its impact on mine waste dump stability:

• Scope: To review and synthesize existing research on spontaneous combustion in mine waste dumps from both underground and open-pit mining operations, to focus on the mechanisms of spontaneous combustion, its thermal effects, and the impact on geomechanical stability and slope failure in mine waste dumps, to examine current monitoring and control methods, identify gaps in the literature, and suggest directions for future research.
• Methodology: Comprehensive literature review of global studies including case studies, laboratory experiments, theoretical analyses, and monitoring techniques related to spontaneous combustion and slope stability in mine waste dumps, Critical evaluation and integration of findings to provide a holistic understanding of the interactions between spontaneous combustion and geotechnical behavior of mine waste materials.
• Key Findings/Perspectives: Spontaneous combustion causes temperature changes, material degradation, and gas generation, which significantly affect the geotechnical properties of mine waste materials, which increase the risk of slope instability and potential landslides in mine waste dumps, Current mitigation strategies are costly and complex, highlighting the need for improved monitoring and control methods, Identified research gaps include the need for more field data, experimental validation, and development of tailored mitigation approaches, The review emphasizes the importance of integrating spontaneous combustion considerations into risk assessments and waste management practices to enhance safety and environmental protection.

Issue 3. In the start of the paper add 1-2 sentences on how historical mining practices contributed to the current volume and distribution of waste.

Response: I would appreciate it if you could clarify your point further so I can better understand your suggestion. Here is an example (Introduction): “Mine waste is commonly deposited in surface storage areas, forming mine waste dumps. As mining activities continue and available surface space remains constrained, these dumps tend to increase both in height and overall volume. This continual growth raises significant concerns regarding their long-term geotechnical stability, environmental impact, and the safety of nearby communities and infrastructure. In Poland, mining waste…”

Issue 4. Lines 42-45. Add some actual cases, consider citing ref. doi:10.33271/mining18.04.139 in what metal pollution of water within the mining-industrial region bordered to Poland is investigated and discussed. Also consider citing ref. doi:10.51301/ejsu.2022.i6.06 to emphasize the importance of sustainable waste and tailings management.

Response: The suggested references fall outside the scope of this manuscript and do not align with its primary focus.

 Issue 6. Section 2 ("Mechanisms of Spontaneous Combustion") lacks a clear thematic progression. The description of the four phases (lines 82-86) is useful, but the structure would benefit from numbered subheadings (2.1 Induction phase) for each phase, along with clearer differentiation between processes like oxidation, thermal accumulation, and ignition thresholds.

Response: Please note that this is a review paper primarily based on previously published research from around the world. As such, the manuscript focuses on highlighting key aspects and overarching themes rather than providing exhaustive detail on each study. The specific details, methodologies, and data can be found in the extensive list of references cited throughout the text. Repeating those details within the manuscript would not only be redundant but would also significantly increase its length without adding substantial value to the core discussion.

Issue 7. Some sections blend review and original commentary without clarification. For instance, Figure 2 (line 71) is presented as documentation of an actual slope failure in Poland, yet no source is cited, and no details on the study or data collection are provided. Is this a case study or simply an illustrative example?

Response: This is simply an example intended to demonstrate that landslides can be triggered by spontaneous combustion.

Issue 8. While the article compiles various references, no critical evaluation or comparison of findings is provided. For instance, Table 1 (line 158) presents Factor of Safety (FoS) values, but the method of analysis, assumptions, and validation are not discussed. What model was used? What software? Is it based on published data or the authors’ calculation?

Response: The data presented in Table 1 is based on my own analysis, conducted for a coal mine waste dump located in Poland. The slope stability analysis was designed to illustrate how spontaneous combustion-induced cracks and fractures can reduce the Factor of Safety (FoS), thereby increasing the risk of slope failure. While the analysis provides valuable insight into the geotechnical implications of spontaneous combustion, the specific details—such as the analytical method, assumptions, validation process, and software used—are not the primary focus of this review. The intention is to support the broader discussion by highlighting a practical example, rather than to present a full case study or methodological investigation. A full analysis is available and can be shared upon request.

 Issue 9. The authors claim (line 341): /Most existing studies tend to treat thermal and mechanical phenomena in isolation.../ yet no systematic table or summary of these studies is provided to support this claim. A comparative matrix summarizing literature on thermal effects, slope failures, and monitoring would strengthen this point.

Response: Numerous studies have been conducted focusing on the thermal behavior of waste material, environmental impacts, progression of combustion, and the mechanical behavior of waste dump slopes; however, these aspects have generally been studied separately. My intention is to highlight that thermal–mechanical interaction has not yet been considered, representing a gap that should be addressed in future research. This is an important observation. I agree that including a table summarizing research on these topics would be helpful; however, due to the large number of studies, such a table would be excessively long. Instead of a table, relevant references have been added to support this observation.

Issue 10. Many of the cited studies are outdated or duplicated. For example, multiple entries from Polish institutions could be synthesized to avoid redundancy.

Response: In compiling this review, I made a concerted effort to cite all relevant studies available at the time of writing. This was done to ensure a comprehensive and balanced overview of the current state of knowledge, without favouring any particular approach or source.

Issue 11. Figures 4 and 5 are referenced in the text but lack sufficient explanation or proper labeling. For example, Figure 4 shows slope cracks but does not specify the location, time of observation, or instrumentation used.

Response: Figures 4 and 5 are intended to illustrate how spontaneous combustion can lead to the formation of cracks, fractures, and internal cavities within the slope body of a mine waste dump. Specific details such as the exact location, time of observation, or the instrumentation used are not the primary focus of this review. The purpose of including these figures is to support the broader discussion by providing a practical visual example, rather than to offer a comprehensive case study or detailed incident report. A full report can be delivered upon request.

 Issue 12. Figure 6 (city/local heating system configuration) is conceptually interesting but highly speculative and undeveloped. No thermodynamic or engineering feasibility is discussed, nor is there reference to similar systems in practice.

Response: This is purely a conceptual idea at this stage. Figure 6 presents a simplified schematic intended only to illustrate the general concept. To the best of my knowledge, there are currently no known applications of such a system for mine waste dumps worldwide. Naturally, the technical details of this approach would need to be thoroughly developed and tested under real field conditions to assess its feasibility and effectiveness. Future work should focus on evaluating the system’s safety, economic viability, and environmental impact before any practical implementation can be considered.

 Issue 13. The suggestion to use spontaneous combustion as a heat source (line 442) lacks a feasibility study or energy balance analysis.

Response: An alternative approach is to explore the use of spontaneous combustion as a potential heat source. This concept is still in the early idea stage. As previously mentioned, preventive measures to mitigate spontaneous combustion in mine waste dumps are often costly, time-intensive, and labour-demanding. Therefore, instead of fully preventing or suppressing spontaneous combustion, it may be more practical in some cases to control it and harness the heat it generates in a continuous and safe heat source. This concept has been explored, to some extent, in the context of municipal solid waste (MSW) landfills, where controlled heat recovery systems have shown promise. Future research should focus on the development, optimization, and safety of similar systems for mine waste dumps, taking into account site-specific geological, geotechnical, and environmental conditions. Implementation strategies would need to be carried out for each individual case to ensure both feasibility and sustainability.

Issue 5. In the discussion contrast Polish waste accumulation with that of other major coal-producing countries (China, Germany, Ukraine) in the context of ESG strategy to contextualize scale and urgency (doi:10.33271/mining17.01.001; etc)

Response: The suggested reference falls outside the scope of this manuscript and does not align with its primary focus.

Issue 14. The Conclusion simply repeats content from earlier sections. It should instead summarize key insights, unresolved questions, and practical implications.

Response: Conclusions have been improved

 Issue 15. The manuscript addresses an important problem but requires significant improvements. With substantial revisions and clearer focus, the manuscript may become suitable for publication.

Response: Revisions have been made based on your comments and suggestions. Please note that this is a review paper, primarily based on previously published research conducted worldwide. It does not present new experimental work, calculations, or methodological innovations. However, it aims to provide an extensive and comprehensive overview of the existing literature on the topic. Bring an attention on Additionally, it reflects my perspective as an expert in the field, with the hope that this synthesis of knowledge and insight will be valuable to researchers and practitioners who are interested in the subject.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors did a great job updating their manuscript, it can be accepted for publication.

Author Response

Dear Reviewer,

Thank you again for your constructive comments and suggestions on my manuscript

Best regards

Author

Reviewer 3 Report

Comments and Suggestions for Authors

Unfortunately, the author’s responses to the reviewer’s comments are wholly unsatisfactory. Instead of engaging constructively with the feedback, the author has provided superficial replies that read more like dismissive remarks than genuine attempts at improvement. Several responses appear to be generated by artificial intelligence, evidenced by repetitive phrases such as “Details can be provided upon request”. These phrases fail to address the core issues raised.

Moreover, the author has disregarded substantial recommendations provided by the reviewer. Key aspects such as the inclusion of concrete examples, comparative tables, updated literature synthesis, and explicit clarification of the methodology used for their own analysis were either ignored or inadequately addressed. This approach shows a formalistic attitude toward peer review, a reluctance to thoroughly revise the manuscript, and a limited grasp of the expectations for academic rigor.

Author Response

Dear Reviewer,

Thank you for your comments and suggestions on my manuscript. I have carefully rechecked your feedback from the first round and I believe I did my best to address your concerns clearly.

I do appreciate your constructive comments and suggestions seriously during the revision process. However, it seems that my responses may not have fully met your expectations. I assure you that my intention is respectful and collaborative, and I hope you can understand my perspective on the following points.

Let me summarize my position:

1. I did not cite the suggested references because they are out of the specific scope of my research. Additionally, according to the journal's guidelines, I am not sure that recommending specific references for citation is appropriate within the review process

2. Some analyses mentioned are based on my own work. Due to limit of number of pages, I could not include the full details in the current manuscript. However, I am willing to share these analyses with interested readers if they request. There is absolutely nothing to hide here.

3. My responses were written based on your comments and reflect my own understanding. There is no inappropriate use of AI tools in the manuscript preparation. Please note that I am not a native English speaker so there may and will be some grammatical mistakes or repetition. I believe the scientific content remains clear and should be the main focus of the review process.  I think the editorial team will support with language editing If necessary.

4. In general, I respect all reviewers' comments. However, authors are not always required to adopt every suggestion/ recommendation if they believe it may compromise the focus or integrity of the study. 

Once again, I respect your opinion and decision. I hope this response helps clarify my position, and I remain grateful for your time and effort in reviewing my work.

Sincerely,

Author