A Study of the Composition and Dissolution of Jianshui Purple Pottery in Yunnan, China

Round 1

Reviewer 1 Report

This article “Study on composition and dissoulution of Jianshui purple pottery in Yunnan, China” reported the importance of Jianshui pottery as a national delicacy that not only meet the beauty requirement but also the safety requirement in use. The use of pottery is very common in daily life, and this paper takes the Jianshui purple pottery from Yunnan, China, as the object of study. The chemical composition, microstructure, and dissolution of trace elements of the raw purple pottery ore, mixture and the pottery cups are fully tested and analyzed. The analysis of the mechanism of composition change before and after firing of pottery is not very specialized and in-depth, but the pattern of change is briefly discussed.

The research topic of the article is interesting, and the production process and composition of Jianshui purple pottery have been systematically studied and introduced, which has some practical value. However, there are some unclear expressions or writing errors in the manuscript, which are suggested to be revised for publication. The authors need to address the following questions,

1. In the section “3.2. SEM and EDS analysis”, the details of the EDS acquisition are unclear, whether the location of the EDS sampling point is located at a certain point in the SEM image. The authors need to explain how the sampling points were selected.
2. In the section “3.4. Dissolution of trace elements”, in the simulation of the pottery use scenario (3), the extraction solution is evaporated by continuous heating. Meanwhile, the dissolution data show that the trace elements are relatively less dissolved in this scenario. Whether the authors have supplemented the extract solution or not, if there is such a step, it is bound to dilute the concentration of trace elements dissolution.
3. Does LOI mean Loss on ignition? If so, please explain that when you first use this abbreviation.
4. In introduction, " With reference to relevant information, it is confirmed that Jianshui purple pottery is safe as a food-contact appliance." This sentence is an unclear statement. The author should clarify that Jianshui purple pottery is safe and reliable from the point of view of the level of trace elements dissolution, and comparing the standards of food-contact appliance.

Author Response

Dear professor,

 Thank you very much for your review of our manuscript. Your careful reading and critical suggestions will help us to greatly improve the quality and readability of the manuscript. We are pleased to receive your comments and have closely studied and synthesized the information and made substantial changes to the original manuscript. For the convenience of reviewers, the revised manuscript used the "Track Changes" function in Microsoft Word. 

Comments and Suggestions for Authors:

This article “Study on composition and dissolution of Jianshui purple pottery in Yunnan, China” reported the importance of Jianshui pottery as a national delicacy that not only meet the beauty requirement but also the safety requirement in use. The use of pottery is very common in daily life, and this paper takes the Jianshui purple pottery from Yunnan, China, as the object of study. The chemical composition, microstructure, and dissolution of trace elements of the raw purple pottery ore, mixture and the pottery cups are fully tested and analyzed. The analysis of the mechanism of composition change before and after firing of pottery is not very specialized and in-depth, but the pattern of change is briefly discussed.

The research topic of the article is interesting, and the production process and composition of Jianshui purple pottery have been systematically studied and introduced, which has some practical value. However, there are some unclear expressions or writing errors in the manuscript, which are suggested to be revised for publication. The authors need to address the following questions,

1. In the section “3.2. SEM and EDS analysis”, the details of the EDS acquisition are unclear, whether the location of the EDS sampling point is located at a certain point in the SEM image. The authors need to explain how the sampling points were selected.

Response 1: Thanks for your careful reading and valuable suggestions. Since EDS is an elemental analysis of a particular point, we measured several random points for each sample. The statistics of their elemental content were plotted in Figure 7, using the box-plot method. In the box plot, the upper and lower points are the maximum and the minimum values, the upper and lower edges of the box are the upper and lower quartiles, the middle horizontal line is the median, and the middle point is the average value. As you suggested, the explanation about Figure 7 we have added to lines 246~251 of the revision.

 

2. In the section “3.4. Dissolution of trace elements”, in the simulation of the pottery use scenario (3), the extraction solution is evaporated by continuous heating. Meanwhile, the dissolution data show that the trace elements are relatively less dissolved in this scenario. Whether the authors have supplemented the extract solution or not, if there is such a step, it is bound to dilute the concentration of trace elements dissolution.

Response 3: Thanks for your careful reading and valuable suggestions. As you mentioned, the heating will lead to evaporation of the extract, which will increase its concentration. However, we did not refill the extract solution for this group. All dissolution experiments were done under the condition that the extract solution was filled to the pottery cup for the first time. Your question about the dissolution amount being rather lower in the use scenario (3) is reasonable. Our explanation for this is that because use scenario (3) was performed after the first two use scenario experiments, its dissolution value may be lower than the previous experiments. Since all the dissolution are far below the standard, we have not discussed this point in more depth.

3. Does LOI mean Loss on ignition? If so, please explain that when you first use this abbreviation.

Response 3: Thanks for your careful reading and valuable suggestions. As you mentioned, LOI is exactly loss on ignition. We have given a note where it first appears, in line 200 of the revision.

4. In introduction, " With reference to relevant information, it is confirmed that Jianshui purple pottery is safe as a food-contact appliance." This sentence is an unclear statement. The author should clarify that Jianshui purple pottery is safe and reliable from the point of view of the level of trace elements dissolution, and comparing the standards of food-contact appliance.

Response 4: Thanks for your careful reading and valuable suggestions. As you suggested, we have corrected the unclear statement in lines 111, 112 of the revised version.

 

We would like to take this opportunity to thank you again for the reviewing process, which has significantly improved the quality of the work.

 

Yours Sincerely,

Chang Liu

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

you cited X-ray diffraction (XRD) in the introduction and the materials and methods part but didn't show any XRD pattern of raw materials (specifically JSM-R) and sintered ones (JSP-R/O). In my opinion, you should discuss the evolution of the phases formed during sintering also according to XRD results and not only on the basis of the oxides you quantified by means of ICP measurements. If possible, Rietveld refinement would be useful too, to quantify amorphous phases present in the sintered materials.

Other corrections:

• line 17: "dissolution" and not "dissolutin",
• line 18: "various use" and not "varies use",
• line 45: "fully understanding" and not "fully understand",
• line 58: "Yu conducted chemical composition..." should be "Yu determined chemical composition...",
• line 59: "microstructure tests on pottery samples" should be "microstructure of pottery samples",
• lines 90, 91: "Secondly, Jianshui purple pottery is non-90 toxic, tasteless and harmless to human health." Please, add some references to support these claims,
• lines 92, 93: "Jianshui purple pottery in actual use is with the characteristics of hiding tea without mold..." should be "Jianshui purple pottery actual uses are hiding tea without mold..."
• lines 105-107: these are already results and should not be mentioned in the introduction, please delete these lines,
• line 127: please cite also the time per step and the anticathode used for XRD measurements + "SEM observations" rather than "SEM experiments"
• line 130: "by ICP-MS experiment." should be "by ICP-MS measurements.",
• lines 160-167: sintering phenomena. Please, check this paragraph: usually the liquid phase promotes the densification, because of higher atoms diffusion rates, but it it doesn't flow into porosities because its amount is generally limited to avoid samples warping, cracking... Rewrite this paragraph on the basis of the existing literature + line 166: "the density becomes higher", not "harder",
• line 169: "Origin 9.0 software were used" should be "Origin 9.0 software was used",
• line 177: "Al2O3 is the second most abundant composition," should be "Al2O3 is the second most abundant oxide,",
• line 187 "wt%" is the correct abbreviation for "weight%", not "wB/%",
• Table 3: why is iron mentioned as metal "Fe" and "Fe2O3" in the table?
• lines 191, 192: "The clay particles are mostly in the shape of cells, and 191 the edges are surrounded by silk-like and wavy projections and connected to each other.", check it please, it is not clear,
• lines 195, 196: "μm" is the correct abbreviation for "micron", not "um" + leave a blank space between the numerical values and their units,
• line 200: what does it mean that "the interior construction becomes denser"?,
• lines 204-206: "The reason of the holes and bubbles is that the gas in the pottery body has not been exhausted during the firing process, or the gases such as CO, CO2, SO2, etc. generated from raw material clay minerals at high temperatures.": I can understand the formation of CO/CO2 during firing because it is probable that you have calcium carbonate in your samples (please, show XRD patterns!) but what is the source of sulphur? Do you have some sulphides in your raw materials? Please, explain it + consider that some of your raw materials decompose and that some of them melt during sintering, react together and form new phases, which is another reason for pores formation. Please, add this point too to the text and add some references as well. The pores can be bigger too because a higher temperature lowers the viscosity of the liquid phase, 
• Figures 4-6: please enlarge scale bars and respective values, they are not readable at all,
• line 217: how many analysis did you do? how were uncertainty bars calculated in fig. 7? Please, add these information to the text,
• Table 4 & Table 6 & Table 7: "wt%" and not "w(B)",
• line 256: "the dissolution of Pb in the fired products was 0.039 mg/L and 0.053 mg/L,...": what does it mean? Are you mentioning a range of values? If yes, please write: "the dissolution of Pb in the fired products was in the range 0.039 - 0.053 mg/L,...",
• line 288: "dissolution: Pd≤3.0mg/L,..." should be "dissolution: Pb≤3.0 mg/L,...",
• paragraph "4. Discussion" should be rewritten on the basis of XRD results, literature results and previous comments on sintering phenomena. The discussion can't be limited to ICP/MS results + consideration on iron making temperature is not correct as you have fluxes in your material (mainly K2O, TiO2 and a in a more limited way, Na2O) that will form a liquid phase. In addition, the claim that "Fe will melt" is not correct because you don't have iron but iron oxides in your raw materials,
• line 314: "Clay reaches a stable state after firing at high temperatures": what does it mean? Please check the sentence,
• Figure 10: honestly, I don't understand its interest and would recommend to delete it. What is the aim of this figure? It is almost obvious that as the LOI of your raw materials is limited (5.76% for JSM-R), the composition of the fired materials (expressed in oxides) won't be too different from the one of the original mix... A discussion on the content of the phases formed after sintering and their contribution to the mechanical properties of the fired sample would be much more of interest to the Readers... In addition, this figure is not clear at all: what are these dots representing?
• Conclusion: check point 1 in function of previous comments on the temperature of iron making and reduced LOI (5.76% for JSM-R, which is not a so low value). Your comment on iron content reduction is also questionable as alumina and silica contents decreased too after firing (referring to Table 3 results when comparing JSM-R and JSP-O/R results), please check this comment also,
• Check the references, they are not all written in the same format.

Best regards.

 

Reviewer 2

 

Author Response

Dear professor, 

Thank you very much for your review of our manuscript. Your careful reading and critical suggestions will help us to greatly improve the quality and readability of the manuscript. We are pleased to receive your comments and have closely studied and synthesised the information and made substantial changes to the original manuscript. For the convenience of reviewers, the revised manuscript used the "Track Changes" function in Microsoft Word.

 

Comments and Suggestions for Authors:

Dear Authors,

you cited X-ray diffraction (XRD) in the introduction and the materials and methods part but didn't show any XRD pattern of raw materials (specifically JSM-R) and sintered ones (JSP-R/O). In my opinion, you should discuss the evolution of the phases formed during sintering also according to XRD results and not only on the basis of the oxides you quantified by means of ICP measurements. If possible, Rietveld refinement would be useful too, to quantify amorphous phases present in the sintered materials.

Response 1:

Thanks for your careful reading and valuable suggestions. The XRD measurements we perform in this paper on the raw pottery, the mixed clay, and the finished product are mainly used to detect the mineral composition within them. As in this literature, only the chemical composition within them was quantified, and it was found that SiO₂ and Al₂O₃ are the main components in pottery clay (>80%)[1]. Therefore, we only compare the compounds of the three samples quantitatively and do not discuss the evolution of the phases formed in more depth. We are very sorry that we did not save the XRD pattern documents. However, this also requires resampling to complete other related experiments, which can be a little time consuming. If rietveld refinement is necessary, we need more time to supplement the experiments and then complete the work.

Other corrections:

• line 17: "dissolution" and not "dissolutin",. (revised at line 17)
• line 18: "various use" and not "varies use", (revised at line 18)
• line 45: "fully understanding" and not "fully understand", (revised at line 45)
• line 58: "Yu conducted chemical composition..." should be "Yu determined chemical composition...", (revised at line 59)
• line 59: "microstructure tests on pottery samples" should be "microstructure of pottery samples", (revised at line 60)

Response 2: Thanks for your careful reading. These have been corrected in the revised version.

• lines 90, 91: "Secondly, Jianshui purple pottery is non-90 toxic, tasteless and harmless to human health." Please, add some references to support these claims,

Response 3: Thanks for your valuable suggestions. Jianshui purple pottery has a long history and is widely used, and is known as one of the four most famous potteries in China. Its excellent characteristics have been mentioned in many literatures, and we have cited the source of these claims here in support at line 95 of the revised version.

• lines 92, 93: "Jianshui purple pottery in actual use is with the characteristics of hiding tea without mold..." should be "Jianshui purple pottery actual uses are hiding tea without mold..."

Response 4: Thanks for your careful reading. These have been corrected at lines 96,97 in the revised version.

• lines 105-107: these are already results and should not be mentioned in the introduction, please delete these lines,

Response 5: Thanks for your valuable suggestions. We agree with you that this part should not be in mentioned the introduction, and we have deleted it in the revised version.

• line 127: please cite also the time per step and the anticathode used for XRD measurements + "SEM observations" rather than "SEM experiments" (revised at lines 133~137)
• line 130: "by ICP-MS experiment." should be "by ICP-MS measurements.", (revised at lines 133~137)

Response 6: Thanks for your suggestions. These have been corrected in the revised version.

• lines 160-167: sintering phenomena. Please, check this paragraph: usually the liquid phase promotes the densification, because of higher atoms diffusion rates, but it it doesn't flow into porosities because its amount is generally limited to avoid samples warping, cracking... Rewrite this paragraph on the basis of the existing literature + line 166: "the density becomes higher", not "harder",

Response 7: Thanks for your valuable suggestions. We have taken a deeper understanding of the definition of sintering and found that our previous explanation was not rigorous and scientific. Sintering, the transformation of powdery materials into dense bodies, is a traditional process. People have been using this process for a long time to produce ceramics, powder metallurgy, refractory materials, ultra-high temperature materials, etc. Generally speaking, the dense body obtained by sintering after the powder has been molded is a polycrystalline material whose microstructure consists of crystals, vitreous humor and pores. As you suggested, we have rewritten this paragraph explaining the sintering phenomenon in lines 166-171 of the revised manuscript. The word "harder" is also corrected to "higher".

• line 169: "Origin 9.0 software were used" should be "Origin 9.0 software was used", (revised at line 180)
• line 177: "Al2O3 is the second most abundant composition," should be "Al2O3 is the second most abundant oxide,", (revised at line 188)
• line 187 "wt%" is the correct abbreviation for "weight%", not "wB/%", (revised at line 199)

Response 8: Thanks for your suggestions. These have been corrected in the revised version.

• Table 3: why is iron mentioned as metal "Fe" and "Fe2O3" in the table?

Response 9: Thanks for your careful reading. We have analyzed the mineral composition of the raw ores, mixed clay and the finished products of purple pottery, and Fe refers to TFe (Total Fe). Fe₂O₃ is the main form of its presence in the clay. To make it clearer, we corrected the table header and explained it at the end of Table 3.

• lines 191, 192: "The clay particles are mostly in the shape of cells, and 191 the edges are surrounded by silk-like and wavy projections and connected to each other.", check it please, it is not clear,

Response 10: Thanks for your suggestions. We are very sorry that the narrative here is unclear. We have revised it in lines 204,205 of the revised manuscript to focus on the introduction of the edge profile characteristics of clay mineral particles.

• lines 195, 196: "μm" is the correct abbreviation for "micron", not "um" + leave a blank space between the numerical values and their units, (revised at lines 208~210)

Response 11: Thanks for your careful reading. We realized that the wrong abbreviation was used, and this has been corrected in the revised version.

• line 200: what does it mean that "the interior construction becomes denser"?,

Response 12: Thanks for your suggestions. We agree with you that the use of "internal construction" is not rigorous. What we are trying to say is that after mixing and compacting, and with sufficient moisture, the internal texture is denser. We have revised it to "internal texture" in line 213 of the revision.

• lines 204-206: "The reason of the holes and bubbles is that the gas in the pottery body has not been exhausted during the firing process, or the gases such as CO, CO2, SO2, etc. generated from raw material clay minerals at high temperatures.": I can understand the formation of CO/CO2 during firing because it is probable that you have calcium carbonate in your samples (please, show XRD patterns!) but what is the source of sulphur? Do you have some sulphides in your raw materials? Please, explain it + consider that some of your raw materials decompose and that some of them melt during sintering, react together and form new phases, which is another reason for pores formation. Please, add this point too to the text and add some references as well. The pores can be bigger too because a higher temperature lowers the viscosity of the liquid phase, 

Response 13: Thanks for your valuable suggestions. The production of SO₂ gas was based on speculation of coal mine combustion, and we are sorry that this point was so inappropriate. We have deleted the content related to SO₂. Because the raw materials contain CaO, which can react with water and CO2 in the air to form Ca(OH)₂ and then react with CO₂ to form CaCO₃. Therefore, it is reasonable to assume that CO and CO₂ gases are produced during pottery firing. We agree with you that some of raw materials decompose and that some of them melt during sintering, react together and form new phases, which is another reason for pores formation, and the pores can be bigger too because a higher temperature lowers the viscosity of the liquid phase. We have added it as an explanation in the revised version. The phase change of quartz particles is also one of the reasons for pores formation. The expansion of quartz particles at high temperatures and the equivalent shrinkage during cooling leads to the loss of bonding between them and the clay matrix, which can lead to the creation of pores in the pottery[2-5]. As you suggested, we have referred to the relevant literatures and added more discussion in lines 219~227 of the revised version.

• Figures 4-6: please enlarge scale bars and respective values, they are not readable at all,

Response 14: Thanks for your careful reading and valuable suggestions. Clearer scales and respective values have been marked in Figures 4 ~ 6 of the revised versions.

• line 217: how many analysis did you do? how were uncertainty bars calculated in fig. 7? Please, add these information to the text,

Response 15: Thanks for your careful reading and valuable suggestions. Since EDS is an elemental analysis of a particular point, we measured several random points for each sample. The statistics of their elemental content were plotted in Figure 7, using the box-plot method. In the box plot, the upper and lower points are the maximum and the minimum values, the upper and lower edges of the box are the upper and lower quartiles, the middle horizontal line is the median, and the middle point is the average value. As you suggested, the explanation about Figure 7 we have added to lines 246~251 of the revision.

• Table 4 & Table 6 & Table 7: "wt%" and not "w(B)",
• line 256: "the dissolution of Pb in the fired products was 0.039 mg/L and 0.053 mg/L,...": what does it mean? Are you mentioning a range of values? If yes, please write: "the dissolution of Pb in the fired products was in the range 0.039 - 0.053 mg/L,...", (revised at line 285)
• line 288: "dissolution: Pd≤3.0mg/L,..." should be "dissolution: Pb≤3.0 mg/L,...", (revised at lines 317~319)

Response 16: Thanks for your suggestions. These have been corrected in the revised version.

• paragraph "4. Discussion" should be rewritten on the basis of XRD results, literature results and previous comments on sintering phenomena. The discussion can't be limited to ICP/MS results + consideration on iron making temperature is not correct as you have fluxes in your material (mainly K2O, TiO2 and a in a more limited way, Na2O) that will form a liquid phase. In addition, the claim that "Fe will melt" is not correct because you don't have iron but iron oxides in your raw materials,

Response 17: Thank you for your valuable suggestions. Sintering is a very important process in the production of pottery, and has an extremely important impact on the performance and quality of pottery. We neglected to discuss the importance of sintering before, which is very inappropriate. We agree with you that the sintering process should be the focus of discussion. We have rewritten the "Discussion" section after referring to the relevant literature. Figure 10 was removed because it was not the focus of this paper and its presence made the logic of the text misleading. Increasing the firing temperature as well as increasing the firing time will result in improved performance such as the average force, bending strength break, bending modulus, modulus of rupture, density and shrinkage percentage of the pottery[6,7]. We have added a discussion of sintering, citing some of the relevant literatures on pottery sintering. We agree with you that the statement "Fe will melt" is not correct, and we have revisited the idea that iron oxides are melted to form a liquid phase in the presence of fluxes. Thank you for your suggestions, which makes our article logical, well organized and accurate.

• line 314: "Clay reaches a stable state after firing at high temperatures": what does it mean? Please check the sentence,

Response 18: Thanks for your suggestions. We apologize for the lack of clarity of expression here. It should be that the purple pottery embryo has reached a stable state in terms of its internal structure and chemical composition after firing. We have completed the correction of it at lines 361~363 of the revised version.

• Figure 10: honestly, I don't understand its interest and would recommend to delete it. What is the aim of this figure? It is almost obvious that as the LOI of your raw materials is limited (5.76% for JSM-R), the composition of the fired materials (expressed in oxides) won't be too different from the one of the original mix... A discussion on the content of the phases formed after sintering and their contribution to the mechanical properties of the fired sample would be much more of interest to the Readers... In addition, this figure is not clear at all: what are these dots representing?

Response 19: Thanks for your suggestions. The main purpose of Figure 10 is to show the comparison between the chemical composition content of the mixed clay samples measured in this paper with the predicted content calculated from the empirical values of the raw material ratios. The points on the graph represent the content of each chemical component. We agree with you that this is not the focus of this paper, and we present it with the expectation that it will shed light on the improvement of the pottery making process. As you suggested, we deleted this part to make the logic of the article clearer and to make the point expressed in the article more understandable.

• Conclusion: check point 1 in function of previous comments on the temperature of iron making and reduced LOI (5.76% for JSM-R, which is not a so low value). Your comment on iron content reduction is also questionable as alumina and silica contents decreased too after firing (referring to Table 3 results when comparing JSM-R and JSP-O/R results), please check this comment also,

Response 20: Thanks for your valuable suggestions. We have changed the summary of "Conclusion point 1". Instead of referring to iron making as the cause of Fe loss, we have quoted your previous suggestion, stating that iron oxides melt in the presence of fluxes and then lead to a reduction in Fe content. I'm confused about your point of view that alumina and silica contents decreased too after firing (referring to Table 3 results when comparing JSM-R and JSP-O/R results). Therefore, I have extracted a comparison of the components of JSM-R and JSP-O/R (part of Table 3), and highlighted in red the values of the components with significantly higher content compared. It can be visually seen that the Fe and LOI component content decreases significantly as a percentage of the finished product, as well as SiO2 and Al2O3 increase significantly. I think that after sintering, the LOI is removed at high temperature. As well, after the sintering action, the iron oxides are partially lost by melting, resulting in such a change in composition. As you suggested, we have corrected some misstatements in the conclusion of the revised version.

Table 3. Test results of chemical compositions of experimental samples (wt%).

Sample No.	SiO2	Al2O3	TFe	CaO	MgO	K2O	Na2O	TiO2	P2O5	MnO	LOI	Sum
JSM-R	63.45	17.59	7.88	0.43	0.77	2.64	0.08	1.02	0.07	0.04	5.76	99.73
JSP-O	69.95	18.81	5.94	0.32	0.74	2.7	0.11	1.11	0.07	0.03	0.2	99.96
JSP-R	69.67	18.87	5.93	0.38	0.73	2.76	0.14	0.99	0.06	0.04	0.22	99.79

 

• Check the references, they are not all written in the same format.

Response 21: Thank you for your careful reading. We have corrected the formatting of the original and new references in accordance with the formatting requirements for journal references.

 

We would like to take this opportunity to thank you again for the reviewing process, which has significantly improved the quality of the work.

 

Yours Sincerely,

Chang Liu

 

Reference:

1. Meethong, N.; Pattanasiriwisawa, W.; Somphon, W.; Tanthanuch, W.; Srilomsak, S. Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 degrees C. In Traditional And Advanced Ceramics, Sirisoonthorn, S., Jiemsirilers, S., Nilpairach, S., Wasanapianpong, T., Sujaridworakun, P., Chuankrerkkul, N., Eds.; Key Engineering Materials; Trans Tech Publications Ltd: Durnten-Zurich, 2014; Volume 608, pp. 47-+.
2. Tite, M.S. Strength, Toughness and Thermal Shock Resistance of Ancient Ceramics, and Their Influence On Technological Choice. Archaeometry 2001, 43, 301–324.
3. Thér, R. Identification of Pottery Firing Structures Using the Thermal Characteristics of Firing. Archaeometry 2013, 56, 78–99.
4. Podwórny, J.; Wojsa, J.; Wala, T. Variation of Poisson's ratio of refractory materials with thermal shocks. Ceramics International 2011, 37, 2221-2227.
5. Wang, H.F.; Bonner, B.P.; Carlson, S.R.; Kowallis, B.J.; Heard, H.C. Thermal Stress Cracking in Granite. Journal of Geophysical Research Atmospheres 1989, 94, 1745-1758.
6. Kuang, M.; Wang, P.; Luo, Q.; Wei, Z.; Wei, Y.; Peng, H.; Xie, L. Porous pottery of sintered diatomite and adsorption performance of methylene blue. BULLETIN OF THE CHINESE CERAMIC SOCIETY 2016, 35, 2986-2989.
7. Bakar, N.A.; Daud, N.; Nor, S.M.M.; Mohamed, J.J.; Muhammad, N.M.N. The Effect of Firing Duration on Mambong Pottery. In Materials Characterization Using X-Rays And Related Techniques, Sulaiman, M.A., Ahmad, Z.A., Mohamed, J.J., Eds.; AIP Conference Proceedings; Amer Inst Physics: Melville, 2019; Volume 2068.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript deals with a topic which is suitable for Crystals journal. In general, it is well structured and written properly. The results of the dissolution tests are particularly interesting. It is evident that the study can contribute to the existing knowledge about fine pottery manufacture and application, so it deserves an opportunity for publication. However, there are several deficiencies that must be corrected before. The main is the following: if the pores content is so important in this kind of materials, why the authors just check it through a simple observation by SEM? In my opinion, they should perform a detailed characterization of porosity by conventional techniques such as N₂ physisorption and mercury porosimetry, which are available in so many laboratories around the world, to determine the amount of macropores, mesopores and micropores, besides the specific surface area.

In addition, the are other medium/minor corrections to be made as follows:

• All tables and figures must be self-explaining in a scientific article, so the reader does not have to go to the text to fully understand its meaning. In this sense, indicate the technique employed for results shown in Tables 3, 4 and 5 in their corresponding headings. Similarly, caption of Figure 8 must include the meaning of u and P2.
• In relation to the above, Tables 6 and 7 headings should also include the bibliographic references from which data come.
• English, although not so bad, should be better revised by a native speaker for further improvement. Some examples of mistakes are: line 56 (They must be He), line 80 (was must be were), line 82 (as must be in), Figure 1 (Triteness better than The triteness), line 137 (product instead of products), lines 142-156 (avoid mixture of verbal tenses), line 155 (becomes instead of become), line 169 (were must be was), lines 174-186 (revise whole paragraph, do not confuse composition with component), line 223 (Si and K). lines 224-225 (both two must be both or the two).
• Indicate the meaning of LOI acronym at least the first time it is introduced.
• Why the iron content is the only one not expressed as oxide like the rest of elements? 
• In line 241 JSP-P must be JSP-R.
• In line 60, Wang must be Wang and Chen. Similarly, in line 337 Dasari must be Dasari et al.
• Why the letter size is smaller from line 53 to line 76?
• Similarly, make uniform the format of bibliographic references. Sometimes the journal name is in italics and capital letters, also some author names are written in capital letters. Additionally, the journal name must be always wirtten before the year of publication (see refs. 16 and 17).
• Insert some missing separation spaces. For example, in line 32 (areas[2]), line 58 (development[6]), line 63 (pottery[8]), line 260 (24h. 20min[16,17]).
• Line 310: Al2O3 must be Al₂O₃.
• Line 359: 1140 ºC-60 ºC must be 1140 ºC-1160 ºC.
• Lines 195-196: the appropriate symbol for microns is µm.

Author Response

Dear professor,

Thank you very much for your review of our manuscript. Your careful reading and critical suggestions will help us to greatly improve the quality and readability of the manuscript. We are pleased to receive your comments and have closely studied and synthesised the information and made substantial changes to the original manuscript. For the convenience of reviewers, the revised manuscript used the "Track Changes" function in Microsoft Word. 

Comments and Suggestions for Authors:

This manuscript deals with a topic which is suitable for Crystals journal. In general, it is well structured and written properly. The results of the dissolution tests are particularly interesting. It is evident that the study can contribute to the existing knowledge about fine pottery manufacture and application, so it deserves an opportunity for publication. However, there are several deficiencies that must be corrected before. The main is the following: if the pores content is so important in this kind of materials, why the authors just check it through a simple observation by SEM? In my opinion, they should perform a detailed characterization of porosity by conventional techniques such as N2 physisorption and mercury porosimetry, which are available in so many laboratories around the world, to determine the amount of macropores, mesopores and micropores, besides the specific surface area.

Response 1: Thanks for your careful reading and valuable suggestions. First of all, thank you for your comments on our manuscript and it is a great honor to receive your approval of our work. Since XRD, SEM and ICP-MS are the more commonly used experimental methods to study the composition and microstructure of pottery, we have only used these methods for our preliminary study of purple pottery. Your suggestion of N2 physisorption and mercury porosimetry experiments to determine the amount of macropores, mesopores and micropores is very important for the study of purple pottery. We will consider using these methods in further studies to investigate the internal microstructure of pottery in depth.

In addition, the are other medium/minor corrections to be made as follows:

All tables and figures must be self-explaining in a scientific article, so the reader does not have to go to the text to fully understand its meaning. In this sense, indicate the technique employed for results shown in Tables 3, 4 and 5 in their corresponding headings. Similarly, caption of Figure 8 must include the meaning of u and P2.

Response 2: Thanks for your careful reading and valuable suggestions. We agree with you that each figure and table in a scientific paper should be appropriately labeled to make it understandable and readable. As you suggested, we have labeled each figure in the revised version.

In relation to the above, Tables 6 and 7 headings should also include the bibliographic references from which data come.

Response 3: Thanks for your valuable suggestions. As you suggested, we have cited the source literature for the data in the table headings of Tables 6 and 7 in the revised manuscript.

English, although not so bad, should be better revised by a native speaker for further improvement. Some examples of mistakes are: line 56 (They must be He), line 80 (was must be were), line 82 (as must be in), Figure 1 (Triteness better than The triteness), line 137 (product instead of products), lines 142-156 (avoid mixture of verbal tenses), line 155 (becomes instead of become), line 169 (were must be was), lines 174-186 (revise whole paragraph, do not confuse composition with component), line 223 (Si and K). lines 224-225 (both two must be both or the two).

Response 4: Thanks for your careful reading and valuable suggestions. In the revised version, we have corrected the English writing of the article, including some grammatical issues and improper use of words that you have raised.

Indicate the meaning of LOI acronym at least the first time it is introduced.

Response 5: Thanks for your careful reading and valuable suggestions. LOI is exactly loss on ignition. We have given a note where it first appears, in line 200 of the revision.

Why the iron content is the only one not expressed as oxide like the rest of elements? 

Response 6: Thanks for your careful reading. We have analyzed the mineral composition of the raw ores, mixed clay and the finished products of purple pottery. Where Fe refers to TFe (Total Fe), distinguishing it from the soluble iron (SFe) content measured previously. And Fe₂O₃ is the main form of its presence in the clay. To make it clearer, we corrected the table header and explained it at the end of Table 3.

In line 241 JSP-P must be JSP-R. (revised at line 270)

In line 60, Wang must be Wang and Chen. Similarly, in line 337 Dasari must be Dasari et al. (revised at line 62 and line 388)

Response 7: Thanks for your careful reading. These have been corrected in the revised version.

Why the letter size is smaller from line 53 to line 76?

Response 8: Thanks for your careful reading. We apologize for the formatting error here, and we have corrected it.

Similarly, make uniform the format of bibliographic references. Sometimes the journal name is in italics and capital letters, also some author names are written in capital letters. Additionally, the journal name must be always wirtten before the year of publication (see refs. 16 and 17).

Response 9: Thank you for your careful reading. We have corrected the formatting of the original and new references in accordance with the formatting requirements for journal references.

Insert some missing separation spaces. For example, in line 32 (areas[2]), line 58 (development[6]), line 63 (pottery[8]), line 260 (24h. 20min[16,17]).

Line 310: Al2O3 must be Al2O3. (revised at line 353)

Line 359: 1140 ºC-60 ºC must be 1140 ºC-1160 ºC. (revised at line 411)

Lines 195-196: the appropriate symbol for microns is µm. (revised at lines 208~210)

Response 10: Thanks for your careful reading. These have been corrected in the revised version.

 We would like to take this opportunity to thank you again for the reviewing process, which has significantly improved the quality of the work.

 

Yours Sincerely,

Chang Liu

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear Authors,

thank you for having accepted almost all the suggested corrections. However, in my opinion, some other corrections are necessary:

• Table 3: XRD was originally a qualitative analysis that by means of Rietveld refinement is now also a quantitative analysis. Therefore, if you used XRD for the quantification of the phases, please, detail the exact process you followed: which software did you use for Rietveld refinement...? Then, how were you able to detect the such low amount of P2O5 and MnO with XRD? I think these are ICP-MS results. Did you combine the results you got from different experimental techniques? If yes, please, explain it! + explain how you determined the LOI.
• lines 164-169 & 209-216: I can understand that you deleted the XRD files but please, explain the possible phenomena that can happen during sintering by means of literature. Refer, for example, to: Jorge Martin-Marquez et al., Evolution with Temperature of Crystalline and Amorphous Phases in Porcelain Stoneware, J. Am. Ceram. Soc., 92 [1] 229–234 (2009); Jorge Martin-Marquez et al., Effect of firing temperature on sintering of porcelain stoneware tiles, Ceramics International 34 (2008) 1867–1873 + lines  209-216 & 329, 330: why are you mentioning the alpha to beta quartz transformation and the formation of cracks? Did you detect some cracks in your material? If yes, please mention it when commenting FESEM micrographs.
• line 177: silica, alumina, Fe and K2O are the main "oxides", not "chemical compositions" + in place of "Fe", indicate "iron oxides".
• EDS measurements (related to Fig. 7): I can understand that maybe you don't have the same number of measurements on the different samples but "several points" to indicate that you did different measurements is rather vague. Please, give at least a range of values to understand how many points you investigated.
• lines 311-313: what is the meaning of the "average force" and of "bending strength break"? + the "modulus of rupture" represents the bending strength.

Best regards.

 

Reviewer 2

Author Response

Response to Reviewer 2’s Comments (Round 2): 

Dear professor,

Thank you very much for your review of our manuscript. After the review of your first round of comments, we have revised the paper based on your suggestions, which has greatly improved the quality and readability of our paper. We are pleased to receive your further comments and have closely studied and synthesised the information and made substantial changes to the manuscript. For the convenience of reviewers, the revised manuscript used the "Track Changes" function in Microsoft Word.

 

Comments and Suggestions for Authors:

Dear Authors,

 

thank you for having accepted almost all the suggested corrections. However, in my opinion, some other corrections are necessary:

 

Table 3: XRD was originally a qualitative analysis that by means of Rietveld refinement is now also a quantitative analysis. Therefore, if you used XRD for the quantification of the phases, please, detail the exact process you followed: which software did you use for Rietveld refinement...? Then, how were you able to detect the such low amount of P2O5 and MnO with XRD? I think these are ICP-MS results. Did you combine the results you got from different experimental techniques? If yes, please, explain it! + explain how you determined the LOI.

Response 1:

First of all, we must admit a very serious mistake, the "XRD measurement" in the original manuscript should be "XRF measurement". This test was done by sending our samples to the testing center of Jilin University, which has a high level of testing qualification. After detailed inquiry, we realized that XRD measurement can only complete the qualitative analysis of the composition. Through some software or methods, less accurate quantitative analysis results can be obtained. XRF measurement, on the other hand, can perform quantitative analysis of compound composition and is a very common method. We are very sorry for the misunderstanding of the method and the misrepresentation in the original article that led to such a low-level error. We have great respect for your professionalism and your review process. Thank you for going through your professional review process so that this low-level error would not be presented in our manuscript. We are very sorry for such carelessness and indiscipline in our manuscript.

In addition, we have learned about the method of LOI determination. The sample is first ground into powder and then calcined at 1000°C. The LOI value is calculated by comparing the mass difference before and after calcination. The calcined samples were used for XRF measurements to derive the values of the individual oxide content.

We have corrected the original text from "XRD measurements" to "XRF measurements", and the specifications of the relevant test instruments have been revised. The description of the LOI measurement method has also been added to lines 132~135 of the revised manuscript.

 

lines 164-169 & 209-216: I can understand that you deleted the XRD files but please, explain the possible phenomena that can happen during sintering by means of literature. Refer, for example, to: Jorge Martin-Marquez et al., Evolution with Temperature of Crystalline and Amorphous Phases in Porcelain Stoneware, J. Am. Ceram. Soc., 92 [1] 229–234 (2009); Jorge Martin-Marquez et al., Effect of firing temperature on sintering of porcelain stoneware tiles, Ceramics International 34 (2008) 1867–1873 + lines  209-216 & 329, 330: why are you mentioning the alpha to beta quartz transformation and the formation of cracks? Did you detect some cracks in your material? If yes, please mention it when commenting FESEM micrographs.

Response 2:

Thanks for your valuable suggestions, we have referred to the literature and then discussed the phenomena that may happen during the sintering process, and these have been added to lines 169~179 of the revised version. This has led to a better understanding of the sintering process and the sintering mechanism, and these additions will make the manuscript more informative.

The α-β phase transition of the quartz grains is mentioned because it may also be responsible for the pores in the finished pottery. Our SEM images did not reveal cracks in the quartz grains. The formation of cracks is what is found in these literatures and the crack formation is preceded by the expansion of the quartz grains. The expansion of the quartz grains and the equivalent shrinkage during cooling is another possible reason for the pore formation.

line 177: silica, alumina, Fe and K2O are the main "oxides", not "chemical compositions" + in place of "Fe", indicate "iron oxides".

Response 3: Thanks for your careful reading and valuable suggestions. We agree with you that it should be "oxides" rather than " compositions", and that "Fe" should be interpreted as referring to "iron oxides". As you suggested, we have corrected these at lines 176,177 of revised version.

 

EDS measurements (related to Fig. 7): I can understand that maybe you don't have the same number of measurements on the different samples but "several points" to indicate that you did different measurements is rather vague. Please, give at least a range of values to understand how many points you investigated.

Response 4: Thanks for your careful reading and valuable suggestions. We are sorry for this vague statement. Therefore, we have checked the original data and found that all samples have completed more than 5 EDS measurements, and individual samples have completed 10 times. As you suggested, we have corrected this statement in line 248 of the revision.

 

lines 311-313: what is the meaning of the "average force" and of "bending strength break"? + the "modulus of rupture" represents the bending strength.

Response 5: Thanks for your careful reading and valuable suggestions. We found the conclusion that increasing the firing temperature can improve the average force and bending strength break of pottery through this literature[1]. The average force and bending strength break are measured by i Instron Machine and are not specifically described in the article. We contacted the authors of the article by email to inquire about the significance of these two strength indicators and did not receive a reply. Therefore, in order to make our manuscript more rigorous and scientific, I have removed these two concepts. As you suggested, we have explained that the modulus of rupture represents the bending strength in line 329 of the revised manuscript.

 

Best regards.

 

We would like to take this opportunity to thank you again for the reviewing process, which has significantly improved the quality of the work.

 

Yours Sincerely,

Chang Liu 

Reference

1. Bakar, N.A.; Daud, N.; Nor, S.M.M.; Mohamed, J.J.; Muhammad, N.M.N. The Effect of Firing Duration on Mambong Pottery. In Materials Characterization Using X-Rays And Related Techniques, Sulaiman, M.A., Ahmad, Z.A., Mohamed, J.J., Eds.; AIP Conference Proceedings; Amer Inst Physics: Melville, 2019; Volume 2068.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors have considered most of my comments and suggestions. There are still some minor deficiencies like the lack of explanation of labels in Figure 8 in its corresponding caption or the fact that some chemical formulae still need the numbers in subscript format. However, I suppose this can be corrected in the proof of printing. I noticed also that the authors replied properly to the questions addressed by the other reviewers and the manusript was consequently clearly improved. From my viewpoint it can be now accepted for publication.

Author Response

Response to Reviewer 3’s Comments (Round 2):

 

Dear professor,

Thank you very much for your review of our manuscript. After the review of your first round of comments, we have revised the paper based on your suggestions, which has greatly improved the quality and readability of our paper. We are pleased to receive your further comments and have closely studied and synthesised the information and made substantial changes to the manuscript. For the convenience of reviewers, the revised manuscript used the "Track Changes" function in Microsoft Word.

 

Comments and Suggestions for Authors:

 

The authors have considered most of my comments and suggestions. There are still some minor deficiencies like the lack of explanation of labels in Figure 8 in its corresponding caption or the fact that some chemical formulae still need the numbers in subscript format. However, I suppose this can be corrected in the proof of printing. I noticed also that the authors replied properly to the questions addressed by the other reviewers and the manusript was consequently clearly improved. From my viewpoint it can be now accepted for publication.

Response:

Thank you for your work in reviewing our manuscripts, which has greatly improved the quality of our articles. We have explained Figure 8 in its figure name label and double-checked and corrected the compound subscript issue. We are pleased to receive your suggestions.

We would like to take this opportunity to thank you again for the reviewing process.

 

Yours Sincerely,

Chang Liu

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.