Calibrating the Digital Twin of a Laboratory Ball Mill for Copper Ore Milling: Integrating Computer Vision and Discrete Element Method and Smoothed Particle Hydrodynamics (DEM-SPH) Simulations

Round 1

Reviewer 1 Report

The paper is very rich cognitive material. It contains a lot of information, which is the result of careful research work, both of an analytical and purely experimental nature. It is a combination of numerical modeling and the results of a research experiment. Both in the modeling part and in the experimental research part, the authors used modern computational and measurement techniques. The potential use of the work results may contribute to deepening knowledge about milling processes in ball mills.

The paper has minor shortcomings:

- chapter 3.5. Grinding Media

Please insert a space before citing literature [85, 86].

- chapter 3.7. 3. Wet Milling

On line 617, "millig experiments" is missing the letter n (milling).

- chapter 3.8.1. Geometry Definition

In line 660 "Each simulation had 12s (2s for wall movement and 10s of normal mill work)" - insert "." at the end of the sentence.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Very good and interesting article. But there are a few comments and questions:

The paper does not give a justification of the chosen value of filling the mill with grinding bodies. The chosen value of 60 % is excessive.  

The paper studies the dynamics of motion at a rotational speed of 30 of the critical speed, the results at other speeds should have been compared.

The purpose of the modeling is not clear, how the results obtained can help to intensify the grinding process.

The particle size distribution of the ore to be ground is not specified.

The choice of ball size for the studied mills is not justified.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

1. In section 3.4, please clarify the method used to measure slurry density by specifying the type of instruments utilized.

2. In Figure 17, an explanation should be added in the text regarding the appearance of the floating balls in the simulation inside the grinder compared to the experimental image where this phenomenon does not occur.

3. In section 4, the authors report measurements of the dynamic angle of repose for drums of different diameters but do not specify the rotation speeds of the drum. Is this parameter not affected by the drum's rotation speed?

4. The detailed description of the heatmaps shown in Figures 20 and 21 is missing, leaving it unclear what these results represent. It would be beneficial for the authors to provide an explanation of the variables being depicted in the heatmaps and how they relate to the overall findings of the study.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have added to the text of the article. The article can be recommended for publication.