The Investigation of Optimizing Leaching Efficiency of Al in Secondary Aluminum Dross via Pretreatment Operations
Round 1
Reviewer 1 Report
The manuscript shows many experimental results. However, there's little originality and novelty
- The effect of grinding and the hydrolysis behavior of AlN have been already reported in the previous paper of the authors or the paper in the reference list.
- There's no systematic explanation and discussion on leching behavior of Al in SAD
Author Response
Dear reviewer, Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript investigates the effect of pre-treatment operations on subsequent acid leaching. It forms part of a study to improve the extraction of Al in an economical and environmentally friendly manner. The manuscript is good for publication following minor typographical and grammatical error corrections.
Author Response
Dear reviewer, Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Manuscript overview
To the reviewer’s opinion, the article needs major reconstruction. It is not easy enough to follow due to a large number of missing articles (e.g., a, the), missing commas, unnecessary commas, and missing prepositions, as well as some sentences having awkward structures and incorrect verbs (e.g. ‘’was’’ instead of ‘’were’’ or the opposite). The author(s) should review the entire manuscript to search for and correct grammatical (i.e. tenses) and editorial errors. Also, some suggested changes are provided below as specific technical and editorial comments:
- Line 29, 91, 94 and 125: A sentence cannot start with the word “And”
It is a repeated mistake and the author should check the whole manuscript for it.
- Line 45-46: “Therefore SAD…etc.” is a repetition of lines 34-35.
- Lines 81-82: This sentence should be included in the Conclusions
- Line 114,121: “920ml’’ instead of “the 920ml” and “50ml’’ instead of “the 50ml”
- Line 168: ‘’optical conditions’’: does the author mean optimal conditions?
- In the Materials and Methods section the author is referred to ICP-OES but there are no details on the instrument and the conditions of the analysis. Also, the author does not mention in the Results and discussion the results from the chemical analysis with ICP-OES.
Author Response
Dear reviewer, Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
A review of article processes-945404
“The investigation of optimizing leaching efficiency of Al in secondary aluminum dross via pretreatment operations” by Hai-gang Feng, Guo-fan Zhang , Luo-bing Xun, Si-yuan Zhen, De-zhi Liu.
Comments and suggestions which authors may find useful in upgrading manuscript are the following:
- The manuscript requires the major text editing. There are many editorial errors in the manuscript. Also, moderate English changes required.
- Lines 88-89: The leaching experiment device is presented in Fig. S2, not the results of the chemical and phase analysis.
- Page 3, Table 1 - The grain size cannot be negative. What does “-0.45+0.25 mm” mean?
- Between the value and the unit should be a space, e.g. “50 ml”, “20 g”, “7.6 kg” (not “50ml”, “20g”, “7.6kg”). Please, correct it in the paper.
- Figures 1, 2, 4, 5, 6, 7, and S6: The figures show the dependence of various variables on time. It is necessary to add a point (0, 0) for t = 0 on each figure. Also, on X-axis should be the units of the decomposition rate or leaching efficiency. Figures titles: it should be "Fig. 1." or "Figure 1", not "Figure. 1." or Figure.1." (e.g. in a line 170 is “Figure 1”, but in a line 171 is „Figure. 1”).
- Page 4, lines 155-158: What does “(l)” mean in the equations (3-6)?
- Page 5, line 168: The liquid-to-solid ratio (5:2) is unclear. In my opinion it should be “50 ml/20 g” or “5:2 ml/g”, not only “5:2”.
- Page 5, Fig. 2 and page 11, Fig. 7: Leaching efficiency of total Al is poor (about 24% with 6 M HCl, Fig. S3). Have the authors investigated other leaching solutions? Maybe the addition of H2O2 to the leaching solution will increase the leaching efficiency?
- Page 7, line 245: The same question as in point 3. What does “-76 μm” mean?
- Page 9, Fig. 5: In my opinion, Fig. 5 should be moved into Supplementary Materials.
- Delete “pp.” and “p.” in the references.
- Errors are marked in the original file. Please, see an attathment.
Comments for author File: Comments.pdf
Author Response
Dear reviewer, Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Revision of introduction could improve the manuscript. It is thought that this study explains the effect of grinding and water leaching on subsequent acid leaching based on mineralogical analysis. However, still the conclusions is not fully agreed as follows;
“In this study, the efficiency of leaching Al in the SAD by using pretreatment operations was 375 optimized to improve the Al recovery in hydrometallurgical processes.” in conclusions is not accepted because the effect of several factors of grinding and water leaching on leaching of Al from SAD was not systematically studied and presented to find the optimum condition. It can be understood that the study presents that the combined process of grinding + water leaching + acid leaching is a potential method to leach the non-refractory materials such as metallic Al and AlN.
“As a result, ball grinding and 383 water leaching could significantly increase the efficiency of Al leaching from the SAD in subsequent 384 acid leaching operations.” in conclusions is not agreed because the leaching yield of Al shows still low value of below 30%.
Author Response
Dear reviewer,
Thank you again for your comments and suggestions about our manuscript entitled “The investigation of optimizing leaching efficiency of Al in secondary aluminium dross via pretreatment operations (Processes-945404)”. These comments and suggestions are all valuable and helpful for revising and improving our paper and makes me think more deeply about this paper. We have studied the comments and suggestions carefully and have made corrections which we hope to meet with approval. According to the comments and suggestions, all of the revisions are marked in red colour using the "Track Changes" function in the manuscript, and the itemized response is attached. The reviewer's comments and our answers are given in italicized font and normal font, respectively. Changes/Additions to the manuscript are given in red text and the corresponding position in the revised manuscript is given in blue text.
Response to reviewer's comments:
1、 “In this study, the efficiency of leaching Al in the SAD by using pretreatment operations was 375 optimized to improve the Al recovery in hydrometallurgical processes.” in conclusions is not accepted because the effect of several factors of grinding and water leaching on leaching of Al from SAD was not systematically studied and presented to find the optimum condition. It can be understood that the study presents that the combined process of grinding + water leaching + acid leaching is a potential method to leach the non-refractory materials such as metallic Al and AlN.
Answer: First and foremost, thank you for your careful review and relevant comments and suggestions. I am sorry about our unprecise expression in conclusions. The effect of several factors of grinding and water leaching (such as grinding time, water leaching time and temperature, liquid-to-solid, speed of stirring) on leaching of Al from SAD are just studied separately, and then the optimum condition was chosen in this paper. Therefore, thank you again for your comments and we decide to revise the sentence of “In this study, the efficiency of leaching Al in the SAD by using pretreatment operations was 375 optimized to improve the Al recovery in hydrometallurgical processes.” to “In this study, grinding and water leaching are potential pretreatment operations to increase the leaching efficiency of the non-refractory Al components such as metallic Al and AlN in the SAD in the subsequent acid leaching process.”. The correction is in page 14, line 446.
2、 “As a result, ball grinding and 383 water leaching could significantly increase the efficiency of Al leaching from the SAD in subsequent 384 acid leaching operations.” in conclusions is not agreed because the leaching yield of Al shows still low value of below 30%.
Answer: Thank you again for your careful review and relevant comments and suggestions. Although the low leaching efficiency below 30% of total Al results from the high proportion of the insoluble Al compounds, including corundum and magnesia-alumina spinel in the SAD, the above expression in conclusions is indeed inappropriate after our careful consideration. We decide to revise the sentence of “As a result, ball grinding and 383 water leaching could significantly increase the efficiency of Al leaching from the SAD in subsequent 384 acid leaching operations.” to “As a result, the pretreatment operations can increase approximately 5.71% of the Al leaching efficiency from the SAD in subsequent acid leaching operations”. The correction is in page 14, line 459.
We tried our best to make some changes and improve the manuscript. Once again, thank you for your fruitful work. If you have any questions about this paper, please don't hesitate to contact me at the E-mail below.
Yours sincerely,
Haigang Feng
Corresponding author
Guofan Zhang
E-mail: [email protected]
Author Response File: Author Response.pdf
Reviewer 4 Report
I accept the manuscript.
Author Response
Dear reviewer,
Thank you for your careful comments and suggestions about our manuscript entitled “The investigation of optimizing leaching efficiency of Al in secondary aluminium dross via pretreatment operations (Processes-945404)”. Thank you again for approval on our revised manuscript sincerely. If you have any questions about this paper, please don't hesitate to contact me at the E-mail below.
Yours sincerely,
Haigang Feng
Corresponding author
Guofan Zhang
E-mail: [email protected]
