The Recent Progress China Has Made in Mining Method Transformation: Part II Sublevel Caving Method Transformed into Backfilling Method
Round 1
Reviewer 1 Report
Comments and Suggestions for Authorshe article contains interesting numerical tests that focused on determining the stress state around excavations using backfill. The presented research issue indicates the possibilities of using backfill technology in a very effective way, translating into the pattern of production indicators. Below are a few minor comments and suggestions:
1. In the introduction, it should be mentioned that when using backfill materials, the backfilling time should be determined, which should be adjusted to the work schedule (doi: 10.3390/en14113186) and the detailed cooperation of the backfill material should be determined by determining its compressibility (doi: 10.3390/en13205290);
2. In the second chapter, please expand the information on operating losses and dilution in sublevel caving methods;
3. In the third chapter, please add two/three sentences regarding legal regulations, standard values ​​that must be met by backfill material that can be used in Chinese underground mining;
4. In the subsection 4.1, please write what natural hazards occur in the iron ore mine and what is the daily production;
5. Table 2, it is better to use the statement Unit Weight instead of Capacity. In addition, please write in the table what constitutes filling body;
6. In the subsection 4.3, please write what constitutive model was adopted in the numerical models;
7. For the safety factor presented in Table 4, please add the formula that defines it;
8. In the subsection 4.4 in stage 2, please correct the word houses. For stage 4, please write how long it takes to drill and load blast holes and how much explosive is used in one excavation;
9. Figure 11A - the caption should be changed to blasting ring pattern; 10. In the subsection 4.5, the word quarry should be replaced with underground excavation. It is also better to use dilution instead of depletion;
11. In Table 5, please provide the full name for TFe;
12. In the conclusions section, please add one statement regarding the need to protect the surface by using backfill, especially for shallow deposits.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1. The paper provides an analysis of the application of two different excavation methods, so it cannot be said that the „transformation“ of the method is as given in the paper and in the title itself. It is obvious that it is a change in the excavation method, so it is necessary to rewrite the paper accordingly.
2. Page 17: "the sublevel caving method can extract 27668.36 million tons of ore, backfilling method can extract 290.347 million tons of ore, the difference between the two is 1366.34 million tons".
There is an error in the ore quantities stated here.
Secondly, whether the ore losses that remain in the deposit during the developing and undercut of the block for mining, i.e. between the cutting level and the transportation level, have been taken into account.
3. The paper states the costs of expropriation and profit from extra quantity of ore by changing the method. In order to show the benefits of changing the method, a deeper analysis is needed. Excavation costs using open stope mining with cemented backfill are significantly higher compared to sublevel caving.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsDetailed comments for the authors can be found inside the attached PDF file.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsNo comments.
