Effect of Blunging/Dispersion Parameters on Separation of Halloysite Nanotubes from Gangue Minerals
, Mustafa Cinar 3,*, Mert Terzi 1, Ilgin Kursun Unver 1, Yildiz Yildirim 4, Feridun Boylu 5 and Orhan Ozdemir 1,*
Round 1
Reviewer 1 Report
Dear Authors,
The manuscript titled “Effect of blunging parameters on dispersion behaviour of clay sample for purification of low-grade halloysite nanotus” were include the sudy on the removal of impurities from halloysite ore was examined in terms of mechanical dispersion parameters.
As a result of the review, elavuation and all coments was made on the manuscript. Please find the manuscript with comment as attachment file in the journal system.
Best wishes
Comments for author File: 
Comments.pdf
Author Response
General Comment: The manuscript titled “Effect of blunging parameters on dispersion behaviour of clay sample for purification of low-grade halloysite nanotus” were include the sudy on the removal of impurities from halloysite ore was examined in terms of mechanical dispersion parameters.
As a result of the review, elavuation and all coments was made on the manuscript. Please find the manuscript with comment as attachment file in the journal system.
Best wishes
General Response: Dear Reviewer, thank you for your valuable evaluation and comments.
Comment 1 (Page 2_Line 71): I think! except for 2014 and 2015 are given as estimates?
Response 1: AGREED. However, this was a cited figure, and there should be copyright permission from the original publisher to make the changes to the figure. MDPI Editorial Office asked if the paper had permission in case of reproduction or modification, which was used as a cited figure. For this reason, we removed this figure from the manuscript.
Comment 2 (Page 3_Line 99): What are these special methods?
Response 2: DONE. These special methods involve centrifugation, flotation, and leaching. And, this part was included in the text.
Comment 3 (Page 4_Line 148): The devices called ATTRITION SCRUBBER are generally preferred industrially. It has a special mixer propeller structure to increase the efficiency of such devices in the distribution of clay minerals. Why was this type of mixer used?
Response 3: AGREED. This device is generally called a "blunger" in the ceramics industry. However, this process aimed to disperse the clay minerals without changing the size of non-clay minerals. For this reason, that mixer was used as a blunger to adjust the industrial conditions in the laboratory instead of the Attrition Scrubber. The additional sentence was included in the text.
Comment 4 (Page 6_Line 184): The maximum grain size that can be selected in such applications should be 10 mm. Depending on the quartz content, this size can be reduced to smaller sizes. For this reason, in addition to not being able to choose a large size, feeding in a finer size has handicaps in industrial applications. It is a source of negativity for the reduction of clay minerals to these smaller sizes in all seasons. what do you think about industrial application?
Response 4: AGREED. The blunging is used for clay dispersion, and this kind of process is used for low-quality clay ores in the ceramic industry. Actually, there is no precise information about the feed size for blunger according to industries in the literature. This information is useful for those who choose lower feed particle size in the industrial blunging process in terms of clay particle size reduction economy. As it is said, hard materials such as quartz behave as grinding media in blunging operation and particle size distribution is an important parameter. This section of the study is going to provide more information on the size reduction of plastic clays according to the content of hard materials in future studies. In fact, we wanted to investigate the effect of feed size on the dispersion so that we could see the relationship between the feeding size and the change in the quality of the sample after the blunging process in terms of coarser and finer feeding sizes. The additional sentence was included in the text.
Comment 5 (Page 11_Line 254): Better to be referred to as "CONTENT"
Response 5: DONE. It was corrected as "content".
Comment 6 (Page 12_Figure 9(b)): There is no significant difference between the results obtained. This difference may be due to the analysis. How many repetitions of analyzes were done?
Response 6: SOMEHOW AGREED. The Al2O3-SiO2 contents at 20%, 35%, 50% of solids ratios were determined as 31.8%-49.5%, 32.8%-48.5%, and 31.5%-49.8%, and the trend shows the difference. In reality, there is a 1% of Al2O3 and SiO2 content difference among solids ratios in the chemical analyses, which indicates a nearly 2.5% of clay mineral content difference for the mineralogical content of the samples. Moreover, duplicate analysis was done for each sample, the average values were taken into account. The additional sentence was included in the text.
Comment 7 (Page 13_Line 299): How was the temperature of 50 degrees maintained and kept constant?
Response 7: THANKS. We forgot to give this information in the manuscript. A Scilogex magnetic stirrer/heater (Scilogex) was used to keep the pulp temperature constant. Before each test, a pre-test was made and the temperature of the pulp was measured with a thermometer if the temperature was constant at the desired value or not. This information was also added to the manuscript.
Comment 8 (Page 17_Line 393): The effect of mechanical parameters on the dispersion of clays is a very general statement and is a known situation. It would be more useful to give the degree of effect, reasons and results of each parameter mentioned.
I propose to evaluate the effects of changes in parameters such as solids ratio, time, feed size and temperature and support it with literature.
Response 8: AGREED. The mechanical parameters on the dispersion were given with the degree of effect, reasons, and results of each parameter and supported by the literature. This comment was responded to in green color in the conclusion section.
Reviewer 2 Report
The article is one of the many published studies on the purification of clay materials. The authors correctly described the research and phenomena occurring in halloysite nanotubes.
However, the introduction is too broad and should be shortened mainly to research problems in purification processes. It is unnecessary to repeat known knowledge.
All the figures do not contain their sources. If the Fig. Is own then there should also be information about it. The conclusions should be more precise. It is not known what the Authors understand by the term "optimal conditions". This should be clarified.
The Authors should also explain what the purpose of the "study of the influence of mechanical dispersion behavior on the removal of non-clay materials" was and whether the research results will translate into their practical use in industrial practice. Following these notices, this material may be published in "Minerals".
Author Response
The article is one of the many published studies on the purification of clay materials. The authors correctly described the research and phenomena occurring in halloysite nanotubes.
Comment 1: However, the introduction is too broad and should be shortened mainly to research problems in purification processes. It is unnecessary to repeat known knowledge.
Response 1: DONE. The repeated knowledge was removed, and the introduction was shortened according to the information about the purification process.
Comment 2: All the figures do not contain their sources. If the Fig. Is own then there should also be information about it.
Response 2: Figures 1 and 2, which needed citation, were given in the figures’ titles (Figure 2 was removed from the manuscript). The rest of the figures were produced with original data from this study. Additionally, the information about Figures 9 a and b are given in the text.
Comment 3: The conclusions should be more precise.
Response 3: DONE. The conclusions were rewritten to give precise information and shown in green color in the conclusion section.
Comment 4: It is not known what the Authors understand by the term "optimal conditions". This should be clarified.
Response 4: AGREED. Actually, this study was a pre-enrichment study to obtain the optimum or best conditions in the production of samples for the ceramic industry in terms of high Al2O3 contents and low SiO2-Fe2O3 contents of the samples. In this context, the optimal or best conditions were determined according to maximum Al2O3 and minimum SiO2-Fe2O3 contents that were gained from mechanical dispersion parameters as -38 µm sized material.
Comment 5: The Authors should also explain what the purpose of the "study of the influence of mechanical dispersion behavior on the removal of non-clay materials" was and whether the research results will translate into their practical use in industrial practice.
Response 5: The purpose of the study and the practical use of the material was discussed in the conclusions section in green color.
General Comment: Following these notices, this material may be published in "Minerals".
General Response: Dear Reviewer, thank you for your valuable evaluation and comments.
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper deals with the main blunging variables that affect the separation between a clay and non-clay materials. The paper seems a technical report rather than a scientific paper. Nevertheless, the work is well written and well organized. The methodology used for the experimental test is worthy of being considered.
A few points should be clarified, and a few errors should be corrected. In my opinion, the revised paper can meet the interest of the readers of Minerals.
A few remarks:
- Title: a more appropriate title could be: “Effect of blunging parameters on the separation of a low-grade halloysite nanotubes from gangue minerals”.
- Abstract. The sentence: “The particle size reduction……..and grinding operations” could be omitted.
- Line 24: the term “explained” is a statistical term; “determined” is a more appropriate word.
- Line 28: rather than “a solid ratio”, a “pulp concentration of 35 %” is a more appropriate term. “Solid concentration” instead of “solids ratio” should be used all throughout the test.
- Line 45: I would add “titanium”.
- Line 65: the authors could change the sentence to improve the references; “Kaolin group minerals can be classified according to their usage areas, physical characteristics, or mineralogical composition [https://doi.org/10.1016/0040-6031(95)02429-6]
- Figure 2: the authors should specify that the data are consolidated till 2020 and expected from 2021 on. Otherwise, it seems that all data are expected.
- Figure 2: there are two figures on the top of the two first bars that are incomprehensible.
- Line 100: grinding process, forms finer particles of gangue whose separation from clay minerals is difficult. The concept is that fine particles of two different phases, hardly separate form each other.
- Line 142: the authors should say that the mineralogical analysis carried out with X-ray diffraction, is only an estimate with respect to the real mineralogical composition, unless a calibration curve has been made.
- Line 168: why X-ray diffraction was not performed on the -38 micron fraction to determine the clay content of that fraction?
- Line 197-200: the sentence is not clear and should be better explained.
- Line 219: it should be “in Figure 7a” and not 6a.
- Figure 8: all figures should be self-consistent. Please, report in the caption the values of the fixed parameters involved in the process.
- Line 256-257: the authors should highlight that at constant blunging speed, the time affects more the grinding of the more grindable phase.
- Line 286: the term “practice” is better than “application” in this case.
- Line 289: the verb “test” is better than “see”.
- Line 293: after (at 35%), I think “were kept constant” is missing.
- Figure 10-11, captions: ..as a function of temperature; …..as a function of aging time.
- Figure 12, caption: please, report the fixed parameters.
- Conclusions: “the study was aimed to….”
Author Response
Reviewer #3
General Comment: The paper deals with the main blunging variables that affect the separation between a clay and non-clay materials. The paper seems a technical report rather than a scientific paper. Nevertheless, the work is well written and well organized. The methodology used for the experimental test is worthy of being considered.
A few points should be clarified, and a few errors should be corrected. In my opinion, the revised paper can meet the interest of the readers of Minerals.
General Response: Dear Reviewer, thank you for your valuable evaluation and comments.
A few remarks:
Comment 1: Title: a more appropriate title could be: “Effect of blunging parameters on the separation of a low-grade halloysite nanotubes from gangue minerals”.
Response 1: Agreed. Thank you for the recommendation. We changed the title upon your request as the following:
“Effect of blunging/dispersion parameters on separation of halloysite nanotubes from gangue minerals”.
Comment 2: Abstract. The sentence: “The particle size reduction……..and grinding operations” could be omitted.
Response 2: AGREED. The sentence was deleted.
Comment 3: Line 24: the term “explained” is a statistical term; “determined” is a more appropriate word.
Response 3: DONE. The “explained” was changed to “determined”.
Comment 4: Line 28: rather than “a solid ratio”, a “pulp concentration of 35 %” is a more appropriate term. “Solid concentration” instead of “solids ratio” should be used all throughout the test.
Response 4: DONE. The “solids ratio” was changed to “pulp concentration” throughtout the manuscript.
Comment 5: Line 45: I would add “titanium”.
Response 5: Because of another reviewer’s comment, we removed that part from the manuscript.
Comment 6: Line 65: the authors could change the sentence to improve the references; “Kaolin group minerals can be classified according to their usage areas, physical characteristics, or mineralogical composition [https://doi.org/10.1016/0040-6031(95)02429-6]
Response 6: DONE. The given reference was included in the manuscript.
Comment 7: Figure 2: the authors should specify that the data are consolidated till 2020 and expected from 2021 on. Otherwise, it seems that all data are expected.
Response 7: Figure 2 was removed from the manuscript.
Comment 8: Figure 2: there are two figures on the top of the two first bars that are incomprehensible.
Response 8: Figure 2 was removed from the manuscript.
Comment 9: Line 100: grinding process, forms finer particles of gangue whose separation from clay minerals is difficult. The concept is that fine particles of two different phases, hardly separate form each other.
Response 9: AGREED. The following sentence was added in the manuscript.
“and, forms finer particles of gangue which separation from clay minerals is difficult.
Comment 10: Line 142: the authors should say that the mineralogical analysis carried out with X-ray diffraction, is only an estimate with respect to the real mineralogical composition, unless a calibration curve has been made.
Response 10: RIGHT. The following sentence was added to the manuscript.
“Rietveld method was used to determine the quantitative XRD results.”
Comment 11: Line 168: why X-ray diffraction was not performed on the -38 micron fraction to determine the clay content of that fraction?
Response 11: IT IS ALREADY DONE. Figure 14 shows the XRD result of the clay content of 38 µm sized halloysite ore.
Comment 12: Line 197-200: the sentence is not clear and should be better explained.
Response 12: AGREED. This sentence was deleted.
Comment 13: Line 219: it should be “in Figure 7a” and not 6a.
Response 13: CORRECTED.
Comment 14: Figure 8: all figures should be self-consistent. Please, report in the caption the values of the fixed parameters involved in the process.
Response 14: DONE. All constant values for the experiments were given in all the figures.
Comment 15: Line 256-257: the authors should highlight that at constant blunging speed, the time affects more the grinding of the more grindable phase.
Response 15: AGREED. Effect of time on the dispersion is the aim of future study.
Comment 16: Line 286: the term “practice” is better than “application” in this case.
Response 16: DONE. The “application” was changed to “practice”.
Comment 17: Line 289: the verb “test” is better than “see”.
Response 17: DONE. The “see” was changed to “test”.
Comment 18: Line 293: after (at 35%), I think “were kept constant” is missing.
Response 18: DONE. “were kept constant” was included in the manuscript.
Comment 19: Figure 10-11, captions: ..as a function of temperature; …..as a function of aging time.
Response 19: DONE. “as a function of temperature” and “as a function of aging time” were included in the figure captions.
Comment 20: Figure 12, caption: please, report the fixed parameters.
Response 20: DONE..
Comment 21: Conclusions: “the study was aimed to….”
Response 21: DONE. The sentence was changed as follows:
“In this study, the effect of mechanical dispersion behaviours on the removal of the nonclayey minerals such as quartz and goethite from halloysite ore was investigated in detail”.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
No other suggestions
