Research Progress and Typical Case of Open-Pit to Underground Mining in China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

The manuscript entitled: Research Progress and Typical Cases of open-pit to underground mining in China, provides a comprehensive review of the research progress and typical cases of transitioning from open-pit to underground mining in China. The authors discuss key technical issues, including the optimization of development systems, the selection of mining methods, control of slope stability, and determination of mining boundary heights.

In my opinion, the authors effectively establish the context and significance of the topic, highlighting the challenges faced by open-pit mines as they deepen, such as decreased efficiency, increased costs, and some environmental concerns. They argue that transitioning to underground mining has become an inevitable choice for sustainable development in the mining industry, which is nowadays especially visible by taking into consideration the extraction of critical raw materials and reducing dependency on the critical value chains.

The authors in their work discussed in detail 4 key issues: open open-air to underground pioneering systems, mining method, slope stability and boundary pillar thickness by providing a thorough examination of each of these aspects, drawing on a wide range of literature and case studies. In addition, the authors provided the Xinqiao mine case study that makes this manuscript not only a theoretical.

In my opinion, the manuscript is well structured and provides a comprehensive coverage of the topic. Provided literature and Xingiao case study data illustrate the practical application of the discussed technologies, what at the end of the manuscript results with a clear presentation of key findings. The conclusion emphasizes the importance of this research to the sustainable development of China's mining industry, however, this importance it’s also the limitation of that work. In the future, the authors can make a broader discussion including various global case studies.

What authors should revise are minor errors (terminology and editorial) that are present in this manuscript.

1. Line 400, change smoke to fumes. This is more precise information about gaseous products that are the result of an explosive decomposition reaction. (terminology)
2. From subsection 3.5 the authors should provide numeration order according to the editorial guidance. Moreover, they make a continuous numeration in the conclusion section, which is misleading with the numeration that started in section 3.5. (editorial)
3. Change the numeration order or remove it from the conclusion. (editorial)
4. In the whole manuscript, there are editorial errors like lack of “space” after the dot at the end of the sentence (mostly after references) e.g. line 63, 69 etc. (editorial)

In my opinion presented manuscript makes a valuable contribution to the Chinese field of mining and minor errors don’t impact the work’s overall merit. After the minor errors are revised, the manuscript can be published in the journal

Author Response

Detailed Response to Reviewer 1

Manuscript ID:     applsci-3664742

Title of Paper:      Research Progress and Typical Case of open-pit to underground mining in China

Authors:              Shuai Li, Wencong Su, Tubing Yin, Zhenyu Dan, Kang Peng

We appreciate the time and efforts by the editor and reviewers in reviewing this manuscript. The comments provided were all valuable and very helpful for improving our paper. We have carefully studied the comments and have made corrections, which we hope meet with approval. Revised portions are marked in red in the paper. Please note that the following text in blue is our response to the reviewers’ comments, and the text in red is the revised main text.

 

Response to Comments from the Reviewer 1

 

Comment 1:

Line 400, change smoke to fumes. This is more precise information about gaseous products that are the result of an explosive decomposition reaction. (terminology)

Response 1:

Thank you for your valuable comment. We agree with the suggestion to change “smoke” to “fumes” in line 400. We appreciate your professional guidance, which has helped improve the accuracy of the paper.

After each blasting and exhausting the fumes through adequate ventilation, the collapsed ore is transported by the CY-4 diesel front loader through the haulage routes and segmented connecting drifts to the ore chute (as shown in Figure 10B). The load-er's estimated capacity is 406.7 tons per shift. Given that the segmented ore volume is 11,400 tons, the net ore removal time is 29 shifts.

(See line 567 in the article)

 

Comment 2:

From subsection 3.5 the authors should provide numeration order according to the editorial guidance. Moreover, they make a continuous numeration in the conclusion section, which is misleading with the numeration that started in section 3.5. (editorial)

Response 2:

Thank you for your valuable comments. We have corrected the numbering from section 3.5 onward and renumbered the conclusion section according to the journal's editorial guidelines, ensuring consistency and continuity throughout the paper.

(See 3.5 in the article, at lines 544-599)

 

Comment 3:

Change the numeration order or remove it from the conclusion. (editorial)

Response 3:

Thank you for your valuable comments. Regarding the numbering issue in the conclusion section, we have made the necessary revisions according to the journal's editorial guidelines and renumbered the conclusion section to ensure a more standardized format. Additionally, we have reviewed other sections of the paper to ensure all numbering is correct.

(See 4. Conclusions in the article, at lines 650-693)

Comment 4:

In the whole manuscript, there are editorial errors like lack of “space” after the dot at the end of the sentence (mostly after references) e.g. line 63, 69 etc. (editorial)

Response 4:

Thank you for your valuable comments. Regarding the issue of missing spaces after periods at the end of sentences, particularly after references, we have thoroughly reviewed the entire manuscript. We have corrected all instances where a space was missing after the period, especially following references, and ensured that each sentence is properly formatted.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript provides a review of key technologies and challenges in transitioning from open-pit to underground mining. This topic is interesting. However, I recommend rejection in its current form for the following reasons:

• The content and references of the manuscript are insufficient.
• Some words in this manuscript are not in English, such as Figures 8 and 11.
• Why does the conclusion section begin with “6”?
• This manuscript lacks the prospect of underground mining.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The article deals with the interesting issue of converting open-pit mines into underground mines. However, it needs some corrections and cleanup before publication:

1. There is frequent repetition and descriptions in the article relating to the need to transform an open pit mine into an underground mine or related to protective pillars. It is not necessary to repeat the same information in several chapters.
2. There is a caption for Figure 3 on page 6. However, there is no figure there.
3. The title of section 3 should begin with a capital letter.
4. There is a caption of figure 8 on page 9. however, there is no figure there.
5. Figure 8. p. 11 - The descriptions on the figure should be in English.
6. Section 4 conclusion - the list starts with number 6.
7. I found no reference to figure 7 in the text.

The authors should describe more precisely what was the purpose of writing the article and what they wanted to achieve with this article. In my opinion, the technology involved in the mine transformation process was poorly described. More attention should have been paid to explaining the main risks and problems associated with the mining transition. How to deal with the solution of these problems should also be emphasized. The description in the article is so general that it is difficult to generalize clearly about how to deal with other mines.

In the conclusion section, there are repetitions of the content of the body of the article. What is missing is a commentary by the authors, a discussion and a summary providing, for example, guidelines for other mines to follow. I suggest expanding and completing the conclusions. In the conclusions, there should also be a reference to the goals that the authors should set at the beginning of the article.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

There are many drafting issues: 
-all proper names, paragraphs, and titles must be capitalized (e.g., lines 201, 204, 289, 296, and so on), 
-explanations in all figures must be provided in English (e.g., Fig. 8, Fig. 11 a), 
-in Fig. 9 explanations regarding the meaning of each type of pattern used must be provided,
-what does '28d Uniaxial compressive strength' refer to? 
-the text in lines 224, 225 is meaningless, 
-different horizons are given in the paper (e.g., -106, -156, and so on) without the reference horizon (horizon 0) being shown in any figure,

Comments on the Quality of English Language

-technical terms must be used correctly (e.g., front loader instead of  forklift, open pit instead open air and so forth),

- the text needs to be revised to gain clarity.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 5 Report

Comments and Suggestions for Authors

The paper provides a systematic review of technological advancements and typical cases of transitioning from open-pit to underground mining in China. It offers recommendations for adjusting the standardization line used in constructing green mines and aims to provide practical insights for similar mining operations.

The authors focus on several broad themes but do not explore specific solutions or scientific research in depth. While this approach is acceptable for highlighting the importance of multiple key aspects when planning mine development, particularly the transition from open-pit to underground operations, there are main areas that require clarification.

Major comments

1. Firstly, there are no quantifiable metrics provided for assessing environmental protection and the development of green mines. Additionally, no definitions or criteria are outlined for evaluating what constitutes green mining. Although the text suggests that the cited mine complies with green mining standards, it fails to reference specific standards or guidelines. These elements necessitate thorough revision.
2. In Section 3.4, the discussion on the numerical modeling results regarding the stability of the upper column of the original rock emplacement and the upper column of the composite emplacement lacks clarity. The modeling assumptions, input data, and methodology are not included in the text. This subsection should be revised to emphasize these critical details. Furthermore, Figure 8 needs to have its descriptions provided in English rather than Chinese.
3. The discussion regarding the project plans to use backfill materials for Tangling City as an ecological method needs further development, as these actions appear contradictory.
4. The final paragraph of the Conclusions does not accurately reflect the research results. There is insufficient emphasis on the need for further research into key technologies. This paragraph should be revised to address this issue.
5. The paper centers on the Xinqiao Mine as a core case study, but the title emphasizes "typical cases" (plural). It is recommended to include 1-2 additional domestic mine examples (e.g., the open-stope method at the Jinchuan Nickel Mine or the caving method at the Daye Iron Mine) either at the beginning of Chapter 3 or in the conclusion section. Otherwise, the title of the article should be modified. Also, in Section 3, a brief overview of the differences in their transformation method selections and applicable conditions (e.g., ore body dip angle, environmental policies) should be included to highlight the diversity of global practices and strengthen the argument for "typicality."
6. The keyword "green mine" can be further integrated into the main theme. In the conclusion section, consider adding the core value of green mines in the context of open-pit to underground mining (such as reducing tailings discharge through backfilling, reusing closed pit land through ecological restoration projects, and lowering unit energy consumption by improving resource utilization). This should align with national policy directions (e.g., "waste-free mines") and emphasize the social significance of the research.

Minor comments:

1. Almost all figure captions are invalid and should be revised (e.g., Figures 2, 4, 7, 11).
2. Figure 2 is not a map.
3. Figures should have a main caption, followed by captions for each part (a)-(…).
4. Address the duplication issue with Figure 3: Both Sections 2.2 and 2.3 refer to "Figure 3," but the contents differ (one is a schematic diagram of mining methods, the other is a slope model diagram). The figures should be renumbered (e.g., the figure in Section 2.3 should be renumbered to Figure 4) to avoid citation confusion.
5. The caption for Figure 8, mentioned in line 316, is unnecessary.
6. Unit corrections are needed: In Section 3.1, "mine volume 43.6 million m²" should be corrected to m³ (cubic meters); in Section 3.2, "annual production 1.5 million tons per annum" should be revised to "per annum."
7. The English translation of "boundary pillar" varies in the text (e.g., boundary pillar, realm pillar, crown pillar). It is recommended to standardize this term to the internationally recognized term "crown pillar" (e.g., in Sections 2.4 and 3.4) and clearly define it upon first mention (e.g., in the abstract/introduction) to avoid confusion among readers.
8. A similar issue exists with the term "pioneering system," which is translated that way in Section 2.1; however, "development system" is more commonly used in the mining industry. It is recommended that the translation be revised accordingly.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed the comments made in the previous review. In my opinion, this has improved the structure of the article. In my opinion, the article can be published.

Author Response

Manuscript ID:     applsci-3664742

Title of Paper:       Research Progress and Typical Case of open-pit to underground mining in China

Authors:                 Shuai Li, Wencong Su, Tubing Yin, Zhenyu Dan, Kang Peng, Haoxuan Yu.

We sincerely thank the reviewer for their time and positive evaluation of our manuscript. We appreciate your recognition of our work. Since no further revisions were requested, we did not make additional changes in response to this round. We are grateful for your constructive feedback throughout the review process.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

The observations from previous review was proper adressed.

Author Response

Manuscript ID:     applsci-3664742
Title of Paper:      Research Progress and Typical Case of open-pit to underground mining in China
Authors:               Shuai Li, Wencong Su, Tubing Yin, Zhenyu Dan, Kang Peng, Haoxuan Yu.
           We sincerely thank the reviewer for their time and positive evaluation of our manuscript. We appreciate your recognition of our work. Since no further revisions were requested, we did not make additional changes in response to this round. We are grateful for your constructive feedback throughout the review process.

Author Response File: Author Response.docx

Reviewer 5 Report

Comments and Suggestions for Authors

The revised manuscript has improved significantly in response to the reviewer's suggestions. However, there are still some formal deficiencies that prevent me from granting permission for publication in its current form. 

Main comments:

1. In the figure captions, please ensure that the capitalization of captions is correct. Only proper names should be written in capital letters.
2. The unit on the ordinate axis of Figure 6 should be changed and made consistent with SI units; the current unit "thousand t/a" does not seem appropriate.
3. The unit "Mpa" should be written as "MPa."
4. All photographs should clearly indicate the name of the person who took them to confirm their authenticity and ensure they were not sourced from elsewhere or generated by AI.
5. If photographs are sourced from other authors or locations in articles, proper references should be included (for example, see figures 10a and 10b).
6. The reference to figures in the text should match the corresponding figure sub-captions; for example, "10(c)" should not be misrepresented as "10C."
7. References in figure captions must be precise and accurate. For instance, in Figure 4, the reference [50] pertains explicitly to Figure 4(c). It's important to clarify whether this reference is meant only for Figure 4(c) and not for the entirety of Figure 4.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf