Effects of Al(III) Ions at Magnetite Flotation from Quartz by Dodecylamine Al(III)

Round 1

Reviewer 1 Report

Manuscript ID: minerals-1694993

Title: Effects of Al (III) Ions in water on the separation of magnetite from quartz

Authors: Dong Wang et al.

Title must be changed to «Effects of Al (III) Ions at magnetite flotation from quartz by dodecylamine»

“Dodecylamine” must be added to keywords.

Introduction. The authors should add more references about the problem of magnetite flotation from quartz. It is necessary to provide data on various collectors and frothers. The literature review is not complete enough. The authors should write in more detail the novelty of this work.

Section 2.2 What reagent was used as a frother?

Figure 3. Why authors used Al content 4mg/L if in figure 3a the best quartz recovery was at Al content 2 mg/L?

Figure 4. In title for figure authors write “Fe grade”. Does it “Fe grade” or “Magnetite grade”?

Figure 5. What about the stable form of AlCl₄^-?

Authors must add flowsheet of flotation process with optimal parameters (reagents concentration, pH), data of magnetite and quartz recovery, yields (%)

The conclusions are too general. It is necessary to make a division into paragraphs 1) 2) 3). It is necessary to add the main numerical values obtained during this research.

References didn’t write in Minerals style.

Technical errors:

Line 11-13. Please, re-write this sentence. English is not well.

Line 13. Authors must add full chemical formula of dodecylamine.

Line 42-43. This sentence is not complete.

Author Response

Dear Reviewer；

Thanks to the reviewers for their valuable comments, my revisions are as follows;

1. Title changed to Effects of Al (III) Ions at magnetite flotation from quartz by dodecylamine
2. Dodecylamine has been added to the keyword
3. Several references on the separation of magnetite by quartz flotation have been added to the Introduction to reinforce the incompleteness of the Introduction.
4. What reagent was used as a frother?

      The cationic collector dodecylamine has strong foaming properties,          Therefore no foaming agent is added。

5. Why authors used Al content 4mg/L if in figure 3a the best quartz recovery was at Al content 2 mg/L?

   Although the difference between the recovery rates of 2 mg/L magnetite and quartz is large, the recovery rate of magnetite at 4 mg/L is lower, indicating that at this concentration of the agent, a higher-grade magnetite concentrate can be obtained. Therefore, an Al(III) ion concentration of 4 mg/L was chosen.

6. In title for figure authors write “Fe grade”. Does it “Fe grade” or “Magnetite grade”?

Figure 4 is the Fe grade

7. What about the stable form of Al(OH)4-?

Al ions in the solution mainly exist in the form of Al(OH)4-

8. Flotation process flow diagram has been added 
9. The conclusion section is divided into five subparagraphs to clearly state the test results
10. Use endnote software to modify references in ACS format
11. Modified the sentence on lines 11-13
12. Add the dodecylamine chemical equation in line 13
13. Modified the sentence on lines 42-43

Author Response File: Author Response.docx

Reviewer 2 Report

The introduction and description of the experimental part, as well as the rest of the manuscript, covered all important details. The findings are consistent between different methods used and are showing the non-neglectable influence of Al(III) on the floatability of quartz and magnetite. I can not tell anything about the technological feasibility, but I'm sure that some advances in technology can be made from these findings.

However, some sentences are not well constructed and the text should be proofread. Even in the abstract, there are sentences ending with coma, and some sentences do not end with a full stop, which seems insignificant at first but can be confusing for a reader - and is showing that the manuscript is not even spellchecked, let alone proofread.

Some words could have been more carefully chosen, for example, the sentence "The contact angle measurement results showed that the addition of Al (III) ions, the contact angle of magnetite varies significantly than that of quartz, the floatability of magnetite is lower than that of quartz." The sentence is not absolutely clear and should be rewritten. From the main text it can be seen that in the case of the addition of Al(III) ions, the contact angle decrease is greater for magnetite than for quartz.

There are some minor inconsistencies throughout the whole manuscript, for example, Al(III) should be written consistently without a space between Al and (III).

There are different commas in use: "Al(OH)3(s)、Al2O3(s)", also hyphens where they don't belong, line 218: "sur-face", also, the chemical equations will be more readable with spaces around "+" and the arrows.

Some figures are of lower graphical quality and could be re-saved. For example, Figure 5a seems to be of lower resolution than Figure 5b, also it looks like GIF format has been used which should be avoided because of details and colours degradation (there is dot-filled background visible in some figures like Figures 1, 3b, 5a, and 7).

The Figures overall could be of better resolution, it would add to the quality of the manuscript.

Author Response

Dear Reviewer；

    Thanks to the reviewers for their valuable comments, my revisions are as follows;

1. It can be seen from the variation range of the contact angle between magnetite and quartz that after adding Al(III) ions, the contact angle of magnetite decreases more than that of quartz.
2. Al (III) is replaced by Al(III)
3. The arrows and plus signs in chemical equations have been modified and have spaces
4. Figure 5a, Figure 5b and other pictures are in the tiff picture format, which has been modified according to the format required by the pictures of this journal.

Author Response File: Author Response.docx

Reviewer 3 Report

The quality of the infrared spectra could be improved.

Provide electron energy spectra of the samples, if tyou have the equipment for electron photoelectron spectroscopy (XPS).

Author Response

Dear Reviewer;

The XPS testing subject research will be considered later, and I would like to thank the reviewers for their valuable comments.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors answered all questions in detail. A flow sheet of flotation process has been added, conclusions have been significantly improved.
The article can be accepted in this form.