Blasting Fragmentation Study Using 3D Image Analysis of a Hard Rock Mine

Round 1

Reviewer 1 Report

1. Some important results should be given in the abstract.

2. It is better to remove abbreviations from keywords, such as x80 and kuz-ram.

3. The parameters presented in Table 2 should be introduced M, B, Y, L, St, ….

4. What is the reference of relation 4?

5. In relation 4, B and S, both are introduced as spacing? What is the difference between these two parameters?

6. In Figure 9, what is the reason for the difference between the curves obtained from the kuz-ram model and the porta metrics method? Why the kuz-ram model suggests a more uniform granularity and the granularity obtained by the porta metrics method is well. This validation does not seem to be acceptable.

Needs moderate corrections.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper presents an interesting analyze the fragmentation results of itabirites based on distribution of the disassembled material through monitoring photos using the PortaMetricsTM tool.

 However, in my opinion, the paper needs major revision before being accepted for publication.

Below are some comments and suggestions:

 The article is called «Blasting fragmentation study using 3D image analysis of a hard rock mine»

 The 3D image analysis technique is not explained clearly enough.

 Figure 2. Photo of blast test 1 and 3 does not look like the state of rock mass after the blasting. They differ from other photos in the fragmentation of rocks. It looks like the photos were taken after loading  most part of the rock. As for photo 3, it looks more like the result of secondary blasting. How can such different results be compared?

 

Figures 3-9 show that the Kuz-Ram model and PortaMetrics platform analysis results are very different for all blast tests. This difference should be explained. Since the accuracy of 3D analysis remains in question.

 Bottom of page 10 in sentence  «The MMPro results showed that the material was well fragmented, with an average percentage of fragments passing through 150 mm: 69.70% for Tests 1–3; 66.20% for Test 4; and 56.4% for the conventional blasting test.» The authors analyze the average fragment size of 150 mm, why only 150 mm. Usually analyze the entire cumulative curve.

 

Top page 12 in sentence  «As expected, the productivity levels of operations were inversely proportional to the sizes of blasting fragments, specifically studied by X80 in this case». The authors state the obvious. Even Table 4 contains formulas from which the conclusions of the authors follow.

 The article leaves an ambiguous impression. The blasting experiment was an interesting one. However, for a full disclosure of its essence, it was necessary to bring technological schemes with the parameters of the ledge and drilling operations. All photos of the rock mass (to analyze the quality of fragmentation) must be taken immediately after blasting. Scientific novelty is not disclosed in the article.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

I would be very glad to re-review the paper in greater depth once it has been edited because the subject is interesting.

This paper investigates the particle size distribution of the disassembled materials considering different blasting plane parameters. This is an interesting topic. However, there are some important information that shall be clarified before publishing of the article.

(1)    The format of the abstract is not correct. Please read the author guidelines. It is too descriptive and lengthy. Please add some quantities to it and shorten it through focusing on the main point.

(2)    In the introduction, few existing studies examining the progress about particle size distribution and digital image technology are named. The amount, continental depth, and location in the paper where prior literature is discussed could be improved.

(3)    I suggest the authors add page and line numbers when they re-submit it. It will be easier for reviewers to make comments.

(4)    In section 2.3, please add figure description about image process.

(5)    There is no experimental comparison of the research with previously known work, so it is impossible to judge whether the content is an improvement on previous work.

(6)    Please merge Figures 3 to 7.

(7)    The points presented in the conclusion section are not up to the mark. The authors are advised to revise it completely and try to present information, which is a comprehensive summary of the important aspects discussed in the preceding sections. It certainly lacks in its current form.

· Comparison with previous studies must mention in the result section, not in the conclusion section.

· Mention your own results only.

· Mention recommendations.

· Make the conclusion in points with short details.

· Change the name of the section to “Conclusions and Recommendations”.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

applsci-2417768

Blasting fragmentation study using 3D image analysis of a hard rock mine

 

This study is quite interesting. Blasting is important in mining engineering, even sometimes it is the only feasible way to develop the deep underground resources/coal in the hard rock masses. This work is application-orientation and could provide valuable references. 

I appreciate the authors' effort spent on this work. However, the current manuscript should be improved to satisfy with the required quality for publishing in Appl Sci. I kindly have the following comments and suggestions to help the authors improve their manuscript. 

------------------------ Major concerns ------------------------

1.        Introduction. Literature survey seems insufficient. I kindly suggest that to add more up-to-date literature and review them critically. What are the challenges; What are the solutions/methods; What are the drawbacks of different methods; The way used in your study.

2.        Results and discussion section. This section is insufficient. The current analyses are limited at the curve plots of Kuz-Ram and MMPro particle size distributions. I suggest to add more analyses in different viewpoints. For instance, as the authors mentioned in abstract, explosive energy is an interesting viewpoint.

3.        Article's structure. The current layout looks not a good one. I suggest: first, introduce experimental equipment and material preparation; secondly, introduce mathematical formulation of the Kuz-Ram model analysis; thirdly, show the analysis results and digging the underlying phenomena/mechanisms; finally, draw conclusions and give outlooks.

 

------------------------ Detailed comments  ------------------------

1.        Keywords. Kindly suggest that "X80" and "Kuz-Ram" can not be keywords. Please select more general and more specific words as the keywords.

2.        Fig. 1 gives a photo of the machine. However, a schematic/workflow of the machine is more useful than a photo. I kindly suggest that to add a schematic to explain the principle of capturing 3D images.

3.      The product operator in Eq (4) is not standard. It should be removed or replaced by . The superscript “0.5” is better replaced by the sqrt symbol.

4.        Below Eq (4), it is not clear what is "1.10 [2.26]." It seems a typo. Please carefully check other places.

5.        The x-axis of curve plots, like Figs 3-7, is not clear. The space between 1, 10, 100, 1000, is not a uniform distance. Are they should be scaled by logarithm?

 

------------------------ Terminology ------------------------

1.        Poisson's coefficient should be Poisson's ratio.

 

------------------------ Format ------------------------

1.        The font in Table 1 should not be all in bold.

2.        Please carefully check the position of Eq (1).

3.        The contents following Eq (4), "W (m)" and " the standard deviation of the perforation (m);". The unit "(m)" appears twice. Please remove one.

 

Did not detect obvious issues. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

there is no comment.

Moderate editing of English language required.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Accept in present form

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

The comments are the same as the comments in the last-round review. The comments/suggests proposed in the 1st-round review still did not address. Some were even ignored. 

The response letter was unserious, which was informal. In addition, I suggest that the authors should provide a detailed point-to-point response letter in next submission, instead of just a simple answer "Dear reviewer, your suggestions were considered for adapting the article". 

Same as the comments in the last-round review. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 3

Reviewer 4 Report

I leave the decision to the editors. 

N/A

Author Response

Dear Reviewer and Academic Editor,

We consider the suggestions for change according to the academic editor.

To this end, the following considerations were made:

We left highlighted in all the text formatting as found in the attachment, answering your questions.

Also, in reference to your answers:

First Question: Notes for Authors: The corrections made in response to reviewers' comments must be highlighted in the text.

Response: It was carried out, and can be found marked in yellow in the text, all the changes made.

Second Question: "The results showed that the conventional blasting design did not exhibit the best fragmentation of the very compact itabirites..." - design cannot exhibit, it produces.

Response: This topic was removed because no make sense with the article.

Third Question: Future research: "A multivariate statistical analysis of the operational activities of the Mine to 493 Crusher techniques is recommended for future works, seeking to minimize costs

494 and maximize productivity, even comparing with the results obtained by Porta-

495 Metrics." - what does this sentence mean?

Response: This topic was removed of the text and we applied another response who take more clearly what the propose to Future Works.

 

Best Regards,

 

Douglas Soares Moreira,

Engenheiro de Minas Mestrando em Tecnologia Mineral.

Pesquisador Bolsista Instituto Tecnológico Vale.