Assessment of Silica Recovery from Metallurgical Mining Waste, by Means of Column Flotation

Round 1

Reviewer 1 Report

Research authors are relevant. Questions and comments are given in the file.

Comments for author File: Comments.pdf

Author Response

Response to the Reviewer 1

December 15^th, 2019

 

Comments from reviewer:

The metallurgical and mining industries are a source of industrial waste, causing harm to the environment. However, they contain valuable components that are in demand in various industries. The authors' work is devoted to the issue of recycling by the flotation method of waste from a mining enterprise, in which silica is the main impurity compound for the purpose of its extraction.

Upon reading the article have any questions and comments.

 

Are the authors familiar with the work of Russian scientists on the separation of silica from waste products of metallurgical silicon by flotation? Was a comparison of flotation regimes, final indicators?: RESPONSE: The authors did not find the information about these Russian researchers. We only compare with data in the bibliogreaphy found.

 

What specific production waste do the authors use as an object of research? Those. It would be desirable to give information about the technological process, as a result of which the investigated waste is formed. RESPONSE: We modified the intruduction and much of the document text, according to the first two reviews that appeared in the magazine system, but in text now is explained the detailed characteristics of these waste In the introduction the authors write and indicate the content of precious metals in the investigated waste. But in Section 2 “Materials and Methods” there is no data on the chemical composition of a specific sample, only analysis methods are described. That is, as follows from this, the chemical composition of the material from the “Introduction” section is identical with the sample under study? But one must either refer to the introduction or specifically indicate the chemical composition of the studied research object. Then the question is: where is the article in the article about how precious metals behave during the flotation process, in which product they are concentrated, and what are the further prospects for their extraction from the material. RESPONSE: This was already modified and introduced in text.

 

Unnecessary words are on page 3 …. Crystallography Open Database; Match! Software used. RESPONSE: We try to give detailed information related to this topic.

 

There is no information in the conclusions: in which industry do the authors recommend the final product? (since at the beginning of the article, the authors list many possible industries for using silica). RESPONSE: This was included in that section.

 

The article does not include the design of the flotation column and the technological scheme of flotation, which makes it difficult to understand the process as a whole. RESPONSE: Was included a Figure detailing the design of the flotation column.

 

According to the text of the article, the method of dispersing air is not known to which part of the column and how it is supplied. RESPONSE: The method of air dispersion is carried out by applying air controlled by a fluxometer connected to a porous stainless steel disperser, with a pore diameter of 50 µm.

 

In the text of the article it is not clear how and where the depressor is presented. The supply of a depressor and a collector to the same apparatus is unacceptable. RESPONSE: The depressant is not used in experimentation, it is only compared to the literature, in which if it was used.

 

It is unclear whether in the first stage of flotation fatty acids are used as collectors in a neutral or weakly basic medium (all further data are given for amines). RESPONSE: In the experimentation dodecylamine, sodium ethyl xanthate and sodium lauryl sulfate were used. In the part of the Batch flotation, dodecylamine was used at Basic pH (pH = 10) and compared with the effect produced by fatty acids in floating quartz, where the pH is used is weakly acidic (pH = 4-7) .

 

The article does not contain data on the correlation of the quality of the concentrate and the flow rate of the collector, which would seem more logical than associating the quality of the concentrate with gas content. RESPONSE: We have the following figures, but we didn´t use them in text. However, if you consider that they are necessary in text we will include them. (Included in OPFD file) From the title of the article “Assessment of Silica Recovery from Metallurgical Mining Waste, by Means of Column Flotation” the goal is not entirely clear. How do authors evaluate silica recovery? Only the gas (air) content is given; the authors try to relate this to the quality of the concentrate of the first and second flotation stages, which is somewhat doubtful. It would be more logical to give a graph of the quality of the concentrate when the gas content changes, to determine the optimal and, at the optimum value, to bring the dependence of the quality of the concentrate on the consumption of the reagent, pH, etc. There is no required data for this name. However, there is no variation in the gas content data, specific data are provided for which there is no explanation - why exactly these data are used. RESPONSE: Silica recovery was evaluated by characterization by EDS and DRX. Optimal values were used for the first and second stage of Batch (tables point 4), to determine the concentrations in BATCH. Also we have the following results to validate the title and the content of text (Included in PDF file)

Thanks again for your time devoted to this review

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding authors

Author Response File: Author Response.pdf

Reviewer 2 Report

The work of Salinas-Rodríguez et al. investigate the floatation process of a mining tailing obtained from the Dos Carlos mine in Mexico. The flotation presented allow to separate SiO2-rich minerals from other present in the tailing. The paper is not properly written with several flaws in the exposure and lack of clarity on the objective and key result of the study. In my opinion this paper does not meet the standard for a scientific publication. I have provided below some comments that could help improve this research.

 

Line 36 to 54 provide a general background on some concepts related to reuse of and recycling of minerals and materials but is not focused with respect to the topic of the manuscript. There is a reference to the European Union (relevance?), a reference to circular economy, sustainable supply chain etc. (relevance?). The paper discusses recovery of silica from mining tailings but there is no assessment on the cost, environmental impact (for example use of frothers. etc.). For example, it is not clear how the process described in line 67 to 81 is a more sustainable alternative to simply mine high purity silica sand and leave the mining tail untouched. I suggest the author rephrase the introduction.

Line 62 states “can be effectively reused”. How? Is this process already in operation? Also, the reader does not necessarily know what the Dos Carlos mine is. I assume it is gold ore for cyanidation? There should be a comparison between the composition of the ore to be processed and the waste.

Line 99 to 102. Where are the SEM results?

Line 105. Handheld devices are known to be unreliable. Any comment? Also, I could not follow where these XRF data where used in the text.

All the parameters used in the paper (Jg, Db, etc.) need to be properly introduced and explained. The reader has no clue to what this refer to. Line 127. How was the retained gas determined? Again, all variables need to be explained and detailed.

3D graphs are not advisable because difficult to read. Axis are not sufficiently clear or readable

Line 140. How was the bubble size determined?

The bulk of the data seem to describe an optimization of the parameters of the flotation process, an approach that present little novelty.

 

 

The manuscript requires extensive language revisions. Several sentences are unclear or do not make sense. I suggest a professional language editor check and revise the manuscript

 

The financial disclosure at the bottom of the manuscript is not fully clear. It is stated that no funding was received and while some of the authors acquired funding at the same time

 

Some of the references do not seem relevant (e.g., ref. 7, ref.9, ref 13. Etc.)

 

Author Response

Response to the Reviewer 2

December 15^th, 2019

 

Comments from reviewer:

Line 36 to 54 provide a general background on some concepts related to reuse of and recycling of minerals and materials but is not focused with respect to the topic of the manuscript. There is a reference to the European Union (relevance?), a reference to circular economy, sustainable supply chain etc. (relevance?). The paper discusses recovery of silica from mining tailings but there is no assessment on the cost, environmental impact (for example use of frothers. etc.). For example, it is not clear how the process described in line 67 to 81 is a more sustainable alternative to simply mine high purity silica sand and leave the mining tail untouched. I suggest the author rephrase the introduction.

RESPONSE: The introduction was modified trying to be more attached to the content. Lines 36 to 45 were eliminated and almost all the concepts about recycling reduced.

Line 62 states “can be effectively reused”. How? Is this process already in operation? Also, the reader does not necessarily know what the Dos Carlos mine is. I assume it is gold ore for cyanidation? There should be a comparison between the composition of the ore to be processed and the waste.

RESPONSE: This process is not yet in operation. The obtained results will be patented joint with that obtained for silver and gold leaching. On the other hand, the description of the dam “Dos Carlos” was included in text joint with the comparison of material before and after flortation.

Line 99 to 102. Where are the SEM results?

RESPONSE: The results are now included in text

Line 105. Handheld devices are known to be unreliable. Any comment? Also, I could not follow where these XRF data where used in the text.

RESPONSE: It was a mistake in the first redation of text. The XRF equipment was not handheld and was now properly described in text.

All the parameters used in the paper (Jg, Db, etc.) need to be properly introduced and explained. The reader has no clue to what this refer to. Line 127. How was the retained gas determined? Again, all variables need to be explained and detailed.

RESPONSE: All has already explained in text.

3D graphs are not advisable because difficult to read. Axis are not sufficiently clear or readable

RESPONSE: All graphs were changed to be more redable

Line 140. How was the bubble size determined?

RESPONSED: It was explained in text

The manuscript requires extensive language revisions. Several sentences are unclear or do not make sense. I suggest a professional language editor check and revise the manuscript

RESPONSE: English was reviewed

The financial disclosure at the bottom of the manuscript is not fully clear. It is stated that no funding was received and while some of the authors acquired funding at the same time

RESPONSE: It was pointed that for publishing fees only, was recieved funding, but not for experimental and general analysis for work

Some of the references do not seem relevant (e.g., ref. 7, ref.9, ref 13. Etc.)

RESPONSE: All them were deleted, and there were too relevant.

 

 

Thanks again for your time devoted to this review

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors, 

the article is focused on the interesting topic. But the experimental parts of it has a low scientific value. The experiments are described without necessary accuracy for example no data about the flotation column (no figure attached). The results are quite rough data sets with the bunch of graphs. The is no discussion section and the conclusions are obvious and they are only some general statements. The article must be completely re-worked. After that I would like to review it again.

 

Sincerely,

Reviewer

Author Response

RESPONSE.

Firstly, thank for your comments that helped us to improve text. The introduction part has been modified and in the section 2 was attached a Figure showing the experimental design used in the work. Secondly, a discussion section was added, and finally text was reviewed in the language edition.

 

Thanks again for your time devoted to this review

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

After answering questions and comments, the aricle improved markedly, including grafs and pictures. Figure 1 should be improved. My wish: in the analysis of scientific sources, exampes can be given by siilar methods (in particular, flotation) in relation to the studied mterial (silica) and from other objects containing it. 

Author Response

Response to the Reviewer 1

December 26^st, 2019

 

Comments from reviewer:

After answering questions and comments, the article improved markedly, including graphs and pictures. Figure 1 should be improved. My wish: in the analysis of scientific sources, examples can be given by similar methods (in particular, flotation) in relation to the studied material (silica) and from other objects containing it. 

RESPONSE: Firstly, figure 1 was changed for another improved. According to the comparison requested, it was included at the beginning of discusion part.

 

Once again, thanks for your time devoted to this review

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding auth

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors have implemented significant changes to the original manuscript, bringing it up to a suitable standard for scientific publication. Overall the experimental design and data presented are not particularly novel or informative. However, the data may still have some value for the community. I would appreciate if the authors could better elaborate on possible use of the feldspar residue and possibly on how the SiO2-rich component could be used with respect to other sources of quartz (for example direct sand mining). Otherwise the paper could be published in my opinion.    

Author Response

Response to the Reviewer 2

December 21^st, 2019

 

Comments from reviewer:

The authors have implemented significant changes to the original manuscript, bringing it up to a suitable standard for scientific publication. Overall the experimental design and data presented are not particularly novel or informative. However, the data may still have some value for the community. I would appreciate if the authors could better elaborate on possible use of the feldspar residue and possibly on how the SiO2-rich component could be used with respect to other sources of quartz (for example direct sand mining). Otherwise the paper could be published in my opinion.

RESPONSE: The requested paragraph was linked to the conclusions section, tried to be as consistent as possible.

 

Once again, thanks again for your time devoted to this review

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

 

I do appreciate the substantial improvement you made. Now, the article has much higher quality. However, it is still low/medium quality in comparison to the average quality of the articles published in the journal. Nevertheless, now I believe it can be suitable for publishing in the journal. 

Sincerely,

Reviewer

Author Response

Response to the Reviewer 3

December 21^st, 2019

 

I do appreciate the substantial improvement you made. Now, the article has much higher quality. However, it is still low/medium quality in comparison to the average quality of the articles published in the journal. Nevertheless, now I believe it can be suitable for publishing in the journal. 

Sincerely,

Reviewer

 

RESPONSE.

Firstly, thank for your comments that helped us to improve text.

 

Your comments and your support for the results presented. Additionally, reinforcing information has been included for the conclusions, based on the results obtained.

Once, thanks for your time to do this review.

 

Sincerely

 

Eduardo Cerecedo & Juan Hernández

Corresponding authors

Author Response File: Author Response.pdf