Study of K-Feldspar and Lime Hydrothermal Reaction: Phase and Mechanism with Reaction Temperature and Increasing Ca/Si Ratio
Round 1
Reviewer 1 Report
Dear Authors,
this paper is well organized and it shows interesting reaction aspects such as kinetic study.
this paper can be published after following minor correction.
Table 1: Tem -> Temp.
Equation 5, I can not obtain this equation with differentiate Eq. 4 as written in paper.
and what is d1 in Eq. 5?Author Response
Reviewer 1:
Dear Authors,
this paper is well organized and it shows interesting reaction aspects such as kinetic study.
this paper can be published after following minor correction.
Table 1: Tem -> Temp.
Answer: Done. The authors modified them.
Equation 5, I can not obtain this equation with differentiate Eq. 4 as written in paper.
and what is d1 in Eq. 5?
Answer: Eq. 5 should be written:
Ea=-R dlnD/(d(1/T)) (5)
Eq. 5 can be obtained in terms of the following transforming:
lnD=lnA-Ea/RT=lnA+lne^(（-Ea/R×1/T）) (6)
The above equation was differentiated and could be obtained:
dlnD=dlnA+dlne^(（-Ea/R×1/T）)=-Ea/R×dln 1/T (7)
Therefore, we can obtain Eq. 5 by transforming Eq. (7).
Thanks for your suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Minerals-417951
Study of K-feldspar and lime hydrothermal reaction: phase and mechanism with reaction temperature and increasing Ca/Si ratio
By Shanke Liu, Cheng Han, Jianming Liu
Rewiew
This article is a continuation of the series of works by Authors on the research of the interaction of K-feldspar with Lime. In this particular article, the effect of temperature and Ca/Si ratio on the degree of decomposition of K-feldspar and obtaine various types of minerals. This paper will be interest to a wide range of scientists who are creating new composite materials based on the Ca-Al-Si-K-O-H system. I recommend to publish it after minor revisions.
Language: In general, the English is good and proficient, no remarks found with my English skills.
Content: The structure is good and all relevant parts are included clearly. Only the following points and questions were found and are suggested to be checked and/or clarified:
1. Line 98-106. What is the type of autoclave used? How was the liquor mixing? What is the rotation speed of the agitator? What pressure was in the autoclave at the temperatures 160-250 °C?
2. How to carry out X-ray of samples after a hydrothermal process?
3. Line 109. Why is the process duration exactly 13.6 hours?
4. Fig.2 shows the main results of the work. It is necessary to increase these figure. In my opinion, it is necessary to add chemical compounds to the figure in order to quickly and clearly understand the area of the existence of various minerals. The article does not give the chemical formulas of the considered minerals, only in the supplementary. It makes difficult to understand the material.
5. Table 1. No chemical formulas in the table. You can leave the abbreviations, but it seems to me that it is better to add another column in which chemical formulas are indicated. It is very inconvenient to constantly read the note to the table.
6. Figure 4 and Figure 5 need to increase. Figures 5b and 5c are arranged unevenly relative to each other.
7. Line 362. Fig.8 “A magnified image” can be changed by SEM magnified image.
8. Line 364. Chapter 3.3. The article does not show the dependencies of K-feldspar dissolution. Only chemical composition in the supplementary.
9. What equation was used to determine the kinetics and why? Shrinking core model: 1-(1-α)1/3?
10. References 10 deleted doi:https://doi.org/10.1016/j.cemconres.2007.11.005.
11. References 15, 16, 17, 27, 28, 29, 30, 46, 48, 57 some number should appear as subscript.
12. References 46. “220-+” What the correct pages?
13. In all references must be changed “degrees C” to °C.
Comments for author File: 
Comments.pdf
Author Response
Reviewer 2:
Minerals-417951
Study of K-feldspar and lime hydrothermal reaction: phase and mechanism with reaction temperature and increasing Ca/Si ratio
By Shanke Liu, Cheng Han, Jianming Liu
Rewiew
This article is a continuation of the series of works by Authors on the research of the interaction of K-feldspar with Lime. In this particular article, the effect of temperature and Ca/Si ratio on the degree of decomposition of K-feldspar and obtaine various types of minerals. This paper will be interest to a wide range of scientists who are creating new composite materials based on the Ca-Al-Si-K-O-H system. I recommend to publish it after minor revisions.
Language: In general, the English is good and proficient, no remarks found with my English skills.
Content: The structure is good and all relevant parts are included clearly. Only the following points and questions were found and are suggested to be checked and/or clarified:
1. Line 98-106. What is the type of autoclave used? How was the liquor mixing? What is the rotation speed of the agitator? What pressure was in the autoclave at the temperatures 160-250 °C?
Answer: It is an autoclave with a 100 ml volume. The reactants were homogenously blended with a magnetic agitator for five minutes at the speed of 500rpm, and then were heated in the autoclave. The pressure in the autoclave was equal to be the corresponding saturated vapor pressure of the water at the temperature when the temperature remained constant.
The authors modified the manuscript to clarify them.
2. How to carry out X-ray of samples after a hydrothermal process?
Answer: In fact, it was the powdered samples were used to collect the diffraction patterns by the X-ray powder diffractiometer.
3. Line 109. Why is the process duration exactly 13.6 hours?
Answer: The original time was set for 20 hours, however, an unexpected interruption of power supply happened during heating. Therefore, 13.6 hours (at least) were estimated as the practical heating time when the temperature remained constant at 190°C.
4. Fig.2 shows the main results of the work. It is necessary to increase these figure. In my opinion, it is necessary to add chemical compounds to the figure in order to quickly and clearly understand the area of the existence of various minerals. The article does not give the chemical formulas of the considered minerals, only in the supplementary. It makes difficult to understand the material.
Answer: I do not understand what is the meaning of “increase” in the sentence “It is necessary to increase these figure”. I guess the reviewer meant that these figures should be enlarged or magnified. This can be easily adjusted in DOC file. The authors added the corresponding chemical formulas in the caption of Figure 2.
5. Table 1. No chemical formulas in the table. You can leave the abbreviations, but it seems to me that it is better to add another column in which chemical formulas are indicated. It is very inconvenient to constantly read the note to the table.
Answer: In order to keep the coherence, the authors added the chemical formulas in the note of Table 1 as in the caption of Figure 2.
6. Figure 4 and Figure 5 need to increase. Figures 5b and 5c are arranged unevenly relative to each other.
Answer: The authors enlarged Figure 4 and modified Figure 5.
7. Line 362. Fig.8 “A magnified image” can be changed by SEM magnified image.
Answer: Done.
8. Line 364. Chapter 3.3. The article does not show the dependencies of K-feldspar dissolution. Only chemical composition in the supplementary.
Answer: The authors had discussed the changes of the dissolution of K-feldspar with different reaction conditions in an early publication (Liu, S.K.; Han, C.; Liu, J.M.; Li, H. Research of extracting potassium, silica and aluminum from potassium feldspar by hydrothermal chemical reaction. Acta Mineralogica Sinica 2009, 29, 320–326). Therefore, the author did not present and discussed the results in the manuscript.
9. What equation was used to determine the kinetics and why? Shrinking core model: 1-(1-α)1/3?
Answer: On the kinetics, the authors discussed it in another published paper (Liu, S.; Han, C.; Liu, J. Study of K-Feldspar and Lime Hydrothermal Reaction at 190 °C: Phase, Kinetics and Mechanism with Reaction Time. ChemistrySelect 2018, 3, 13010-13016). In summary, based on the Jander equation, the hydrothermal reaction was controlled by the diffusion and the dissolution-precipitation in different durations, respectively.
10. References 10 deleted doi:https://doi.org/10.1016/j.cemconres.2007.11.005.
Answer: Done.
11. References 15, 16, 17, 27, 28, 29, 30, 46, 48, 57 some number should appear as subscript.
Answer: Done.
12. References 46. “220-+” What the correct pages?
Answer: Done.
13. In all references must be changed “degrees C” to °C.
Answer: Done.
Thanks for your hard work and suggestions.
Author Response File: Author Response.docx
