Effective Extraction of Vanadium from Bauxite-Type Vanadium Ore Using Roasting and Leaching
, Guanjie Liang 1,3, Wenxiao Huang 1,3 and Wenliang Xiong 1,5Round 1
Reviewer 1 Report
see attached
Comments for author File: 
Comments.pdf
Author Response
Respond to Reviewer 1 Comments
Point 1: Abstract and/or Introduction: for the non-specialized reader, the nature/composition of the mineral (component) illite should briefly be revealed. – Where in this mineral K,H(Al,Mg,Fe)2(Si,Al)4O10(OH)2(H2O) does vanadium come in (i.e. which metal site is substituted by V, and in which oxidation state does it exist?)
Response 1: Thank you very much for your suggestions. We have reviewed relevant literature work and made supplements.
Point 2: Line 127: Again - at least for the non-specialist - the term “vanadium occurs in illite by isomorphism” affords clarification.
Response 2: Thank you very much for your review. We have replenished and refined it again.
Point 3: The sentence (at the end of section 2.2) “c is the concentration of V2O5 in the leaching solution” sounds somewhat strange: V2O5 by itself is insoluble. Same applies to the first sentence in section 2.3: “The V2O5 concentration …”. - Apparently, as suggested by eqns. (2) and (3), vanadium is not present as V2O5 but rather in the form of V2O3 and VO2. Also, in the succeeding section(s), it remains unclear, in which oxidation state vanadium is present in the mineral / in the procedural extraction(s). In fact, in line 226, the authors state that the “valence conversion of V” is promoted (line 226) and, in line 237, refer to “valence state transformation”.
Response 3: Here is our work not careful enough and has been revised and improved.
Point 4: Eqns. (4) and (5): The formulae applied here for ammonium molybdate are somewhat strange (in as far is the ammonium ions are split into protons and dinitrogen); at least these formulae are not confirm with common formulations in chemical equations.
Response 4: Here are the mistakes in our work, and we have made corresponding corrections. Thank you for your advice.
Point 5: Line 288: The term “aqueous munirite” is misleading, since munirite (NaVO3·2H2O), when dissolved in water, transforms to vanadate H2VO4- + Na+aq.
Response 5: Thank you very much for your advice. We have made corresponding modifications, please review it.
Point 6: Lines 333/334: I do not quite perceive the meaning of the sentence “H2O … is conductive to the evaporation of H2O …”
Response 6: There is indeed some improper expression here, we had revised it, please review it, and thank you again for your advice.
Finally, Thank you very much for taking your precious time to review the article in your busy work, and thank you for your recognition of our research work. I hope our effort work can get your approval. Looking forward to your good news!
With kind regards,
Dr. Junhui Xiao
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear authors
The manuscript deals about an interesting topic. However, the manuscript needs to be improved.
I write you some indications:
How was performed the minerallurgical processing of sample ore? What size particle has the sample? The only metal that can be beneficiated was V? Can V minerals been enriched before treatment? Roasting of wide ore made the process very expensive and with high generation of wastes.
Introduction needs to be revised. Authors need to justify the objetive of the research.
Authors said "The V2O5 concentration in the lixivium" . This needs to be corrected. V2O5 was not soluble in water, authors need to indicated the V ion. The term lixivium needs to be changed why leaching solution or lixiviated. In the Figure 3 authors said "V2O5 leaching efficiency". It is V efficiency or V2O5? In the Equation 1, authors also said "V2O5 in the leaching solution". Authors need to homogenize the terminology and to use the correct term. How was V in the leaching solution?
Terms calcined and roasting are different. However, authors used them indistinctly. For example, "Figure 5. a shows that the main components of
the calcined ore" instead in the roasting ore.
Size of Figure 6 needs to be large
In general, the article must be re-organized. The results should be presented in a more orderly manner. Table 3 should be compared with Table 2 and comment on the effect of roasting
Figure 2 shows DG of reaction 2 and 3. The DS of both reactions was <0. As DG=DH-TDS. The slope was positive. However, lines of Figure 2 show very low negative slopes. Please, authors need to revise this Figure and in addition Figure 8 for the same reason.
Authors used terms calcification and calcination. Both processes were different. Authors need to used calcination.
Comments for author File: Comments.pdf
Author Response
Respond To Reviewer 2 Comments
Point 1: How was performed the minerallurgical processing of sample ore? What size particle has the sample? The only metal that can be beneficiated was V? Can V minerals been enriched before treatment? Roasting of wide ore made the process very expensive and with high generation of wastes.
Response 1: Thank you very much for your review. The sample ore is directly mined by the mine and has a particle size of about 10 mm, in which valuable metals include vanadium, aluminum, etc., but currently we are only interested in recycling vanadium. Besides, the ore preconcentration has not been researched at the present stage, so we will consider the pretreatment of vanadium-bearing ore by gravity separation, flotation and other mineral processing methods in the follow-up work.
Point 2: Introduction needs to be revised. Authors need to justify the objetive of the research.
Response 2: Thank you very much for your advice. We have made corresponding modifications and supplements.
Point 3: Authors said "The V2O5 concentration in the lixivium". This needs to be corrected. V2O5 was not soluble in water, authors need to indicated the V ion. The term lixivium needs to be changed why leaching solution or lixiviated. In the Figure 3 authors said "V2O5 leaching efficiency". It is V efficiency or V2O5? In the Equation 1, authors also said "V2O5 in the leaching solution". Authors need to homogenize the terminology and to use the correct term. How was V in the leaching solution?
Response 3: Here is our work not careful enough and has been revised and improved.
Point 4: Terms calcined and roasting are different. However, authors used them indistinctly. For example, "Figure 5. a shows that the main components of the calcined ore" instead in the roasting ore.
Response 4: Thank you very much for your advice. We have made corresponding revisions.
Point 5: Size of Figure 6 needs to be large
Response 5: Here is our drawing is not clear enough and has been modified. Please review it.
Point 6: In general, the article must be re-organized. The results should be presented in a more orderly manner. Table 3 should be compared with Table 2 and comment on the effect of roasting.
Response 6: Thank you again for your suggestion. We have made corresponding modifications and compared table 2 and 3. Please review it.
Point 7: Figure 2 shows DG of reaction 2 and 3. The DS of both reactions was <0. As DG=DH-TDS. The slope was positive. However, lines of Figure 2 show very low negative slopes. Please, authors need to revise this Figure and in addition Figure 8 for the same reason.
Response 7: Thank you very much for your suggestions. We have reviewed the relevant thermodynamic data and made calculations, and redrawn Figure 2 and Figure 8. Please review it.
Point 8: Authors used terms calcification and calcination. Both processes were different. Authors need to used calcination.
Response 8: Thank you again for your advice. In this paper, "calcification roasting" refers to roasting the ore after adding calcium salt, so we think "calcification" is more suitable. In addition, "calcification" is also used in references [9],[12],[13].
Finally, Thank you very much for taking your precious time to review the article in your busy work, and thank you for your recognition of our research work. I hope our effort work can get your approval. Looking forward to your good news!
Yours sincerely,
Dr. Junhui Xiao
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Authors have improved the manuscript. However, there are some mistakes that they need to revise.
For example, "particle size of 45 to 74 um", please change um by μm
The introduction needs to be improved. The need to do the research should be reflected.The introduction should show a greater connection between the different paragraphs.
Authors said "The raw material used in this study was obtained from Shaanxi Province, China". How was performed the preparation of sample for their subsequent analysis by XRD and subsequent metallurgical treatment? How was performed XRD or FRD?
Authors said "The other major chemical groups are SiO2, Fe2O3, Al2O3, and CaO". It is more adequate to said oxides or compounds.
Authors said "Thirty grams of vanadium ore of different granularity" What granularity? "an appropriate amount of distilled water and sulfuric acid was mixed under stirring" What quantity and concentration has been used?
Authors said "The leaching percentage was calculated using Eq." However, then they said the leaching efficiency. Please, use the same terminology
I continues without understand the DG/T curves of Figure 2. Equation 2 and 3 show that H2SO4 was in the liquid phase. However, in the representation of Figure 2, was not representen the change in the slope due to the evaporation point of H2SO4. DS of Equations 2 and 3 was different depending of H2SO4 was in the liquid or gaseous phase. I think authors need to indicate this fact in the equations and needs to revise the thermodinamic data. Authors also need to revise Figure 8 and corresponding equations. Why does the line not reflect the change in slope due to the evaporation of H2SO4?
Authors said "As the roasting temperature continues to rise, the H2SO4 begins to volatilize and decompose in large quantities". What is the exact H2SO4 volatilization and decomposition temperatures?
Author Response
Respond to Reviewer 2 comments
Point 1: For example, "particle size of 45 to 74 um", please change um by μm
Response 1: Thank you very much for your advice. It's true that we're not using units properly here and we have modified it.
Point 2: The introduction needs to be improved. The need to do the research should be reflected. The introduction should show a greater connection between the different paragraphs.
Response 2: Thank you very much for your suggestions. We have consulted relevant literature work and supplemented relevant literature on the necessity of doing this research.
Point 3: Authors said "The raw material used in this study was obtained from Shaanxi Province, China". How was performed the preparation of sample for their subsequent analysis by XRD and subsequent metallurgical treatment? How was performed XRD or FRD?
Response 3: Thank you very much for your suggestions and we have supplemented relevant content.
Point 4: Authors said "The other major chemical groups are SiO2, Fe2O3, Al2O3, and CaO". It is more adequate to said oxides or compounds.
Response 4: Thank you very much for your advice. We have made corresponding revisions.
Point 5: Authors said "Thirty grams of vanadium ore of different granularity" What granularity? "an appropriate amount of distilled water and sulfuric acid was mixed under stirring" What quantity and concentration has been used?
Response 5: We did not express clearly here. Thank you very much for your suggestions. We have made corresponding modifications, please review.
Point 6: Authors said "The leaching percentage was calculated using Eq." However, then they said the leaching efficiency. Please, use the same terminology.
Response 6: Thank you again for your advice. We have made corresponding modifications, please review.
Point 7: I continues without understand the DG/T curves of Figure 2. Equation 2 and 3 show that H2SO4 was in the liquid phase. However, in the representation of Figure 2, was not representen the change in the slope due to the evaporation point of H2SO4. DS of Equations 2 and 3 was different depending of H2SO4 was in the liquid or gaseous phase. I think authors need to indicate this fact in the equations and needs to revise the thermodinamic data. Authors also need to revise Figure 8 and corresponding equations. Why does the line not reflect the change in slope due to the evaporation of H2SO4?
Response 7: It is calculated by consulting literature and combining with HSC Chemistry software. Corresponding supplement has been made. Thank you again.
Point 8: Authors said "As the roasting temperature continues to rise, the H2SO4 begins to volatilize and decompose in large quantities". What is the exact H2SO4 volatilization and decomposition temperatures?
Response 8: Thank you very much for your review. Concentrated sulfuric acid has a boiling point of 611K and is most volatile when it reaches the boiling point. And pure sulfuric acid will decompose at 563K and release sulfur trioxide.
Finally, thank you very much for taking your precious time to review the article in your busy work, and thank you for your recognition of our research work. I hope our effort work can get your approval. Looking forward to your good news!
Yours sincerely,
Dr. Junhui Xiao
Author Response File: Author Response.docx
Round 3
Reviewer 2 Report
Dear Editor,
I consider you have improve the manuscript. However there are two questions that continues to be without solution
First: How was performed the preparation of sample from mine to lab? Or how was performed the minerallurgical preparation? what king of mill? what size?
Second: Figures 2 and 8 have been changed 2 times in a different form and I continues without understand the representation. The DG/T diagrams are know as Ellinghan-Richardson diagramas and show DG=DH-TDS versus T. The transformations of H2SO4 liquid into gas at evaporation temperature of H2SO4 should be reflected in the continues lines as a change in the slope. I don´t know how authors performed calculations but I consider that the Figures need to be revised.
Author Response
Respond to Reviewer 2 comments
Point 1: First: How was performed the preparation of sample from mine to lab? Or how was performed the minerallurgical preparation? what king of mill? what size?
Response 1: We have perfected this part again for your review. Thank you very much for your suggestions.
Point 2: Second: Figures 2 and 8 have been changed 2 times in a different form and I continues without understand the representation. The DG/T diagrams are know as Ellinghan-Richardson diagramas and show DG=DH-TDS versus T. The transformations of H2SO4 liquid into gas at evaporation temperature of H2SO4 should be reflected in the continues lines as a change in the slope. I don´t know how authors performed calculations but I consider that the Figures need to be revised.
Response 2: Your suggestion is very helpful to our study, we have not fully taken into account the effect of sulfuric acid changing from liquid to gas. We try our best to added and adjusted, please review again, thank you for your review of the work, we must strengthen the work of the follow-up research work.
Finally, thank you very much for taking your precious time to review the article in your busy work, and thank you for your recognition of our research work. I hope our effort work can get your approval. Looking forward to your good news!
Yours sincerely,
Dr. Junhui Xiao
Author Response File: Author Response.docx
