Optimization of Hydrochemical Leaching Process of Kaolinite Fraction of Bauxite with Response Surface Methodology

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1-      Characterize the materials with TEM and SEM if possible to determine the morphological change after hydrochemical processing

2-      Change the title of the manuscript to emphasize on the simulation you have done

3-      The caption of figure 4 is too long

4-      Enhance the English language of the manuscript

5-      Write the references according to MDPI style

6-      Part 6 can be removed

7-      Enhance the resolution of the figures

 

Comments on the Quality of English Language

the English quality must be improved

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

In this manuscript, the influence on the leaching process was studied by adjusting the CaO/SiO₂ ratio, temperature, alkaline solution concentration and duration. This study used a central composite design (CCD) and conducted experimental research and calculations on the leaching mode using response surface methodology (RSM) technology. As mentioned in the manuscript, the concentration of leaching solution and leaching temperature are the main factors affecting the leaching effect. The results of experiments carried out using the developed model of the leaching process confirmed the validity of the calculated indicators with an error of 2.01%. However, the experimental methods and statistics used in the manuscript are relatively single. I believe that the paper is qualified for publishing in Processes after a Revision. Please check the attachment.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate editing of English language is required.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The research proposes a leaching process to recover aluminum from kaolinite with a particular application on a bauxite ore.  The process includes a chemical activation with bicarbonate. The detailed objective is not clearly defined in the Introduction section. The objective has to be clearly described in order to be published in a scientific journal. 

The proposed leaching process is original and relevant to the hydrometallurgy field; however, the introduction and results are poorly presented. It is difficult to assess the consistency of the conclusions since the objective is not defined. The manuscript is not publishable in the current form. 

Main suggestions to improve the manuscript:

Add a paragraph at the end of the Introduction section stating the objective of the work. 

Remove the description of the design of experiments from the Introduction section. It is not relevant to work since it is a general description to apply to all articles. The details of design of experiments are well-known and there is no need to include them there. More literature has to be added about kaolinite leaching. 

The material description added to the initial paragraph of the Results section fits better in the Materials and Method section. 

Remove inconsistent text from Line 143: “This section may be divided by subheadings. It should provide a concise and precise”

Check significant figures in Table 5. 

Add more details to the description of Figure 4, units?

Description for Figure in lines 239 to 242? Figure 5? Units of Temp and leaching time?

Line 288, What Figure?

Line 290 What is TCHA? 

Lines 310-312: Patents?

Comments on the Quality of English Language

Moderate editing of English language required. Some sentences are inconsistent. 

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all the requested modifications 

Author Response

Thank you so much for your comments and wishes.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript's quality has been substantially improved. I recommend its acceptance for publication in its present form.

Author Response

Thank you so much for your comments and wishes.

Reviewer 3 Report

Comments and Suggestions for Authors

The research is still poorly presented. It does need more work in order to be accepted for publication. Some of the answers/modifications to previous comment are not sufficient yet. The sentence added as objective is still not clear. Optimization of which leaching process? optimal conditions under which variables? And the response has to be clearly stated.

The results of different techniques are poorly described Figure 2, 5 and 8, X-ray image? What does it mean?

Table 3 and 5: composition adds to a value higher than 100%. The table has description and title, they are redundant.

Line 156: “The complete disappearance of gibbsite and kaolinite occurs” … Gibbsite and kaolinite disappeared or were below the detection limit of the analysis method?

Acronyms are not introduced in the text, for example: TCHA

Figure 7: units in temperature and leaching time, font size of numbers is very small, not legible.  

Table 6: Significant figures of Temperature, Na2O concentrations and CaO/SiO2

Figure 6: Units? The figure has description and title, they are redundant.

Comments on the Quality of English Language

Moderate editing of English language required. Some sentences are inconsistent. 

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

No more comments.

Author Response

Thank you for your comments and well wishes