Review Reports

Round 1

Reviewer 1 Report

In general, the work presents important result on the processing of arsenic containing gold-bearing concentrate. In the same time, the manuscript should be completely re-written for publication.

 

1. General commentaries on the INTRODUCTION structure.

The Introduction is divided into several subsection. The first 5 paragraphs include the description of modern methods for arsenic removal from gold-bearing ores/concentrates. Other subsections discuss the data obtained in previous works of authors of the present study and their colleagues obtained using approaches similar to those used in the present work.

It is better to clarify the reason to divide the subsections. For example, at the beginning of subsection 1.1 the following sentences may be added:

“In the work [number of reference], laboratory scale trials on the treatment of gold-bearing concentrate were performed. The concentrate containing [main minerals and element content].”

At the end of the subsection, few sentences, which descript main results of the work may be added.

Subsection 2.2 provides data on arsenic mineral behavior. At the end of the subsection, few sentences describing the main conclusions obtained based on the information should be added. For example:

“Thus, the differences in the behavior of different arsenic compounds lead to the following problems form the point of view of ore processing….”

The subsection 1.3. is titled “Ways to solve problems”. The problems should be clearly formulated in previous sub-sections.

In the last paragraph of the introduction, one sentence, which clearly formulate the goals of the present work should be included.

2. Line 32. Check the term “composite gold-containing….ores”. The term “gold-bearing ore” is more commonly used. The term “composite” ore is not clear.

3. Lines 32-33. “arsenic in the form of sulfides or compounds.” [? which compounds?]

4. Subsections 2.1, 2.2, 2.3 describe the equipment used. Thus, these section may be combined into one subsection, for example, “Setup and experiments”.

5. Section 3 should be titled “Results”.

6. Did you mix both concentrates (Gravitational and Flotation)? Describe the composite obtained.

Also, describe the granulation in the section 2. Materials and methods.

7. Add the section “Discussion” after results.

The main points of the “Discussion” should include:

- the comparison of the results obtained in the present work with those, obtained in previous works; also, describe the novelty and main advantages of the present article;

- describe the complete route of the concentrate processing using your method; the product obtained should be processed to extract the gold and silver: describe possible options (direct cyanidation, smelting into copper matte) and their advantages/disadvantages;

- describe further methods for arsenic utilization;

- the concentrate contained significant fraction of carbon, which is a problem for Bakyrchik ores, could you estimate the effect of your treatment on carbon content and carbonaceous matter behavior?

Also, it should be noted that there are a lot of different methods for treatment of arsenic containing concentrates (roasting, POX, BIOX, ALBION), which make it possible to destruct arsenopyrite, deliberate gold for further cyanidation and produce relatively safe arsenic wastes (scorodite). You should compare the technology proposed in your wok with the methods used in industry.

English must be checked by a qualified translator.

Author Response

The authors are appreciating the careful reading of the article and valuable comments by the reviewer. All changes are highlighted in blue in the manuscript.

 

Comment 1. It is better to clarify the reason to divide the subsections. For example, at the beginning of subsection 1.1 the following sentences may be added: “In the work [number of reference], laboratory scale trials on the treatment of gold-bearing concentrate were performed. The concentrate containing [main minerals and element content].” At the end of the subsection, few sentences, which descript main results of the work may be added.

Response 1. Agree with the comment. Corrected.

 

Comment 2. Subsection 2.2 provides data on arsenic mineral behavior. At the end of the subsection, few sentences describing the main conclusions obtained based on the information should be added. For example: “Thus, the differences in the behavior of different arsenic compounds lead to the following problems form the point of view of ore processing….”

Response 2. Agree with the comment. Corrected.

 

Comment 3. The subsection 1.3. is titled “Ways to solve problems”. The problems should be clearly formulated in previous sub-sections.

Response 3.  Corrected.

 

Comment 4. In the last paragraph of the introduction, one sentence, which clearly formulate the goals of the present work should be included.

Response 4. Corrected.

 

Comment 5. Line 32. Check the term “composite gold-containing….ores”. The term “gold-bearing ore” is more commonly used. The term “composite” ore is not clear.

Response 5. Agree with the comment. Corrected.

 

Comment 6. Lines 32-33. “arsenic in the form of sulfides or compounds.” [? which compounds?]

Response 6. Agree with the comment. Corrected.

 

Comment 7. Subsections 2.1, 2.2, 2.3 describe the equipment used. Thus, these section may be combined into one subsection, for example, “Setup and experiments”.

Response 7. We have divided the section "Materials and Methods" into separate subsections 2.1, 2.2, and 2.3 purposefully. They describe the various processes. In this way, it will be easier for readers to find the necessary information regarding the apparatus and the principle of its operation.

 

Comment 8. Section 3 should be titled “Results”.

Response 8. Corrected

 

Comment 9. . Did you mix both concentrates (Gravitational and Flotation)? Describe the composite obtained.

Response 9. In the process of technological testing on the new apparatus, the flotation and gravity concentrates were not mixed due to their different granulometric composition. Both concentrates were subjected to vacuum thermal treatment separately.

 

Comment 10. Also, describe the granulation in the section 2. Materials and methods.

Response 10. Agree with the comment. Corrected.

 

Comment 11. Add the section “Discussion” after results. The main points of the “Discussion” should include:

- the comparison of the results obtained in the present work with those, obtained in previous works; also, describe the novelty and main advantages of the present article;

- describe the complete route of the concentrate processing using your method; the product obtained should be processed to extract the gold and silver: describe possible options (direct cyanidation, smelting into copper matte) and their advantages/disadvantages;

- describe further methods for arsenic utilization;

- the concentrate contained significant fraction of carbon, which is a problem for Bakyrchik ores, could you estimate the effect of your treatment on carbon content and carbonaceous matter behavior?

Also, it should be noted that there are a lot of different methods for treatment of arsenic containing concentrates (roasting, POX, BIOX, ALBION), which make it possible to destruct arsenopyrite, deliberate gold for further cyanidation and produce relatively safe arsenic wastes (scorodite). You should compare the technology proposed in your wok with the methods used in industry.

Response 11. Agree with the comment. Corrected.

Reviewer 2 Report

Please find my comments attached.

Comments for author File: Comments.pdf

The manuscript is written in rather good English. However, there are some minor English mistakes. I listed some of the English mistakes below my scientific comments.

Author Response

The authors are appreciating the careful reading of the article and valuable comments by the reviewer. All changes are highlighted in green in the manuscript.

 

Comment 1. Abstract: In the abstract, the general context of the paper is missing. Also, the aim of the paper is not sufficiently highlighted.

Response 1. Necessary additions have been made to the article text.

 

Comment 2. Figure 2: Could the authors put the size of the assembled shaft?

Response 2.  The shaft is located inside a vertically arranged tubular electric furnace. The diameter of the shaft space is 155 mm. The shaft height is 1150 mm.

 

Comment 3. Line 255: Can authors specify what does it mean large volumes in this context?

Response 3.  In practice, for the processing of Bakyrchik refractory gold-arsenic ores in the process of gravity enrichment, up to 10 tons per day of gravity concentrate containing from 15 to 25% arsenic was formed. The created apparatus with a set capacity will allow it to process the entire volume of the concentrate formed per day.

 

Comment 4. Table 1: The content of elements in "Flotation" is not sum up to 100%. Why? Is it a mistake? Could the author re-design the Table to make it more convenient for readers?

Response 4. Agree with the reviewer's comment. The design of the table has been changed. The table shows the main components of the concentrate, the contents of the rest are given in the "other" column.

 

Comment 5. Table 1: In the lower rows, the results of the chemical composition are up to two digits after the decimal point, while in the upper rows, just up to one digit after the decimal point. Why? Differences in the precision of measurement?

Response 5. Agree with the comment. Corrected.

 

Comment 6. Table 2: There is uncertainty of temperatures, but other values are shown without +- Why?

Response 6. The temperature regimes in the reaction space of the sublimator were controlled automatically at set temperatures. At the same time, inertial temperature fluctuations inside the furnace space during the supply and disable of current loads were ± 10–15 degrees. Necessary additions have been made in subsection 2.2.

 

Comment 7. Figure 4: I don't see information about SEM analyses in the Materials and Method section.

Response 7. The analysis was carried out on a JEOL JXA-8230 electronic raster microanalyzer (JEOL, Japan). This information is available in subsection 2.5.

 

Comment 8. Figure 5: Difficult to believe that AsS is present based on this XRD pattern. I do not see the peaks related to AsS. Could the authors comment on this?

Response 8. According to the semi-quantitative phase analysis, the main phase of the condensate is As₂S₃ (up to 93%). The content of AsS is about 7%, so the intensity of the peaks related to this compound is not so high compared to the peaks of As₂S₃. Especially with the peak located at an angle of 18 Å.

 

Comment 9. In lines 348-354 is the same text as in lines 359-365 and in lines398-404. It should be corrected!!! The authors should read again the whole manuscript.

Response 9. Necessary changes have been made to the article text.

 

Comment 10. In lines 355-358 is the same text as in lines 405-408. It should be corrected!!!

Response 10. Necessary changes have been made to the article text.

 

Comment 11. Line 20-21: “Technological tests on sublimation of arsenic sulfides” should be “Technological tests on the sublimation of arsenic sulfides”

Response 11. Agree with the comment. Corrected.

 

Comment 12. Line 35: “in the lattice of” should be “in the lattice in”

Response 12. Agree with the comment. Corrected.

 

Comment 13. Line 124: “outer” should be “the outer”

Response 13. Agree with the comment. Corrected.

 

Comment 14. Line 175: “The solution of these problems” should be “The solution to these problems”

Response 14. Agree with the comment. Corrected.

 

Comment 15. Line 183: “rheological” should be “the rheological”

Response 15. Agree with the comment. Corrected.

 

Comment 16. Line 206: “mixing” should be “a mixing”

Response 16. Agree with the comment. Corrected.

 

Comment 17. Line 236: “rheological movement” should be “the rheological movement”

Response 17. Agree with the comment. Corrected.

 

Comment 18. Line 270: “steam outlet” should “the steam outlet”

Response 18. Agree with the comment. Corrected.

 

Comment 19. Line 350: “process arsenic-containing” should be “process of arsenic-containing”

Response 19. Agree with the comment. Corrected. 

Reviewer 3 Report

The authors of this article designed a sublimator and achieved near removal (more than 96- 99%) of arsenic in the gold-containing composite concentrate at low and atmospheric pressure. There are still some problems in the article, and the author is recommended to improve it. It is suggested that this manuscript can be accepted after minor revisions. Listed below are detailed comments on the author's manuscript.

 

1.       Page 3 – line 105, "…%: Ni – 2.8; Cr – 16.2; Fe – 41.3; As – 2.8; S – 20.7; SiO2 – 4.0." There is an error in this sentence, please check the full text.

2.       Page 4 – line 170, "…the Le Chatelier principle towards the formation of vaporous associates of arsenic." It is recommended that references be added here.

3.       Page 8 – line 348, Page 9 – line 359, Page 10 – line 398, The sentence "The distribution of the main elements – sulfur and iron, in compounds with arsenic, 348 as well as arsenic for products of…" appeared three times. Please check.

4.       Page 9 – line 355, Page 10 – line 405, The sentence "When analyzing the results of processing gold-arsenic composite…" appeared twice. Please check.

5.       Figure 4(B) is not represented in the corresponding figure title.

6.       There are two part 3. in the text. Please check.

Author Response

The authors are appreciating the careful reading of the article and valuable comments by the reviewer. All changes are highlighted in yellow in the manuscript.

 

Comment 1. Page 3 – line 105, "…%: Ni – 2.8; Cr – 16.2; Fe – 41.3; As – 2.8; S – 20.7; SiO2 – 4.0." There is an error in this sentence, please check the full text.

Response 1. Here are the main components of the cake.

 

Comment 2. Page 4 – line 170, "…the Le Chatelier principle towards the formation of vaporous associates of arsenic." It is recommended that references be added here.

Response 2.  The necessary citation was added.

 

Comment 3. Page 8 – line 348, Page 9 – line 359, Page 10 – line 398, The sentence "The distribution of the main elements – sulfur and iron, in compounds with arsenic, 348 as well as arsenic for products of…" appeared three times. Please check.

Response 3.  Agree with the comment. Corrected. 

 

Comment 4. Page 9 – line 355, Page 10 – line 405, The sentence "When analyzing the results of processing gold-arsenic composite…" appeared twice. Please check.

Response 4. Agree with the comment. Corrected.  

 

Comment 5. Figure 4(B) is not represented in the corresponding figure title.

Response 5. Agree with the comment. Corrected. 

 

Comment 6. There are two part 3. in the text. Please check.

Response 6. Agree with the comment. Corrected. 

Round 2

Reviewer 1 Report

The article was sufficiently improved. Therefore, it may be accepted. Minor editing of English language required as the text contains some typos.

Reviewer 2 Report

The authors implemented all my comments correctly.

The Quality of English has improved.

Reviewer 3 Report

 Thank you for taking into account the suggestion of this reviewer. Most of the changes have been done, and the rest have been justified clearly. Congratulations, you have done a great work.