Efficient Use of Water in Tailings Management: New Technologies and Environmental Strategies for the Future of Mining

Round 1

Reviewer 1 Report

This is an interesting survey, although it is unclear what it adds to the existing literature. Perhaps, it extends current thinking to new areas in South America. If so, there should be more on the value of SA cases. The authors have made an effort to present their research in clear language with a minimum of jargon, but the paper is undermined by inadequate mastery of English. A thorough language edit is needed. The figures and tables are the best parts of the paper, and more explanation of their contents and implications would improve the paper. (The purpose of including the process diagram on page 12, however, is not explained.) On the other hand, some background information is superfluous or redundant, and statements of opinion should be explained or removed. For example, we don't simply accept that equity and environmental conservation should be considered unless they have some implications for mining operations, even though we may believe that they should. An interesting question, not addressed in this paper, is how mines can be/have been convinced to take these community values into consideration. See the uploaded file for specific comments.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1:

Please see the attachment.

Response to the Comments and Suggestions for Authors

This is an interesting survey, although it is unclear what it adds to the existing literature. Perhaps, it extends current thinking to new areas in South America. If so, there should be more on the value of SA cases. The authors have made an effort to present their research in clear language with a minimum of jargon, but the paper is undermined by inadequate mastery of English. A thorough language edit is needed.

Ok the language editing has been done.

The figures and tables are the best parts of the paper, and more explanation of their contents and implications would improve the paper. (The purpose of including the process diagram on page 12, however, is not explained.)

Ok, Explanation have been added.

On the other hand, some background information is superfluous or redundant, and statements of opinion should be explained or removed.

This has been given careful consideration. Explanations have been added.

For example, we don't simply accept that equity and environmental conservation should be considered unless they have some implications for mining operations, even though we may believe that they should.

Ok considered in the new version of the article.

An interesting question, not addressed in this paper, is how mines can be/have been convinced to take these community values into consideration.

Ok but that idea is out of the scope of this article.

See the uploaded file for specific comments.

This has been given careful consideration

Thank you for your comments and suggestions.

Regards

Carlos Cacciuttolo Vargas

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

In your manuscript you have well illustrated new alternatives to water supply, such as desalination of seawater, direct use of seawater or recovery of tailings water. The message in this paper focuses on the possibility of applying different water supply technologies or their combination, implementing adequate water management strategies that take into account: environmental issues, technical issues, strict regulatory frameworks, community requirements and cost-effective strategies, resulting in reduced water replenishment and need for water for exploitation (m³ per metric ton of treated ore).

I think the following should be done:

1. Describe: In the chapter 5. Results of Evaluation of Application of Dewatered Tailings Methodologies at Large Scale Mining Study Case:

Costs are evaluated on the basis of water usage relative to the production  efficiency of the mine. In copper ore deposits where the quality of ore grade is low, the cost of water used per unit weight of metal obtained is high. Therefore, mining companies have to as-sess the cost effectiveness of using brackish or desalinated water. As a re-sult, mining companies are attempting to improve the efficiency of their water use in operations, by reducing water losses due to infiltration, evaporation or effluent generation.

• Please, all this needs to be clarified. Other parameters that affect the cost of production, ie the flotation process, should also be mentioned. Where the quality of the ore is low with metal content, of course the flotation process is burdened with higher costs. What about the combination of flotation reagents for specific cases?
• List at least a few methods of waste treatment options including re-flotation when it comes to high quality minerals

1.  Figure 13. Schematic view of mining project with desalinated water use

- Напишите значење ознака на слици и поправите слику

1. Taking into account the reasons announced above exist economic and environmental drivers to: (i) consider the conversion to thickened/paste or tailings/filter cake disposal technology, and (ii) consider the supply of sea water for mining processes. These aspects will be the new design and operation trends of Greenfield and Brownfield mining proјеct

- Explain which of the following procedures has comparative advantages and why

4. Although the development of thickening and filtration technologies has advanced significantly in recent years, more research / studies are needed to understand their behavior, focusing on achieving good performance in higher production with different tailings particle size distributions.

- Explain why. There are a number of manuscripts on the influence of particle size on flotation efficiency

5. Figures 3 and 4 show typical water flows in a mill and a thickening plant and a tailings dump in a mining project.

      - Text in pictures to be in Times New Roman, or cite literature. This should be   harmonized in the other pictures as well

Best regards

Author Response

Dear Reviewer 2:

Please see the attachment

Dear authors,

In your manuscript you have well illustrated new alternatives to water supply, such as desalination of seawater, direct use of seawater or recovery of tailings water. The message in this paper focuses on the possibility of applying different water supply technologies or their combination, implementing adequate water management strategies that take into account: environmental issues, technical issues, strict regulatory frameworks, community requirements and cost-effective strategies, resulting in reduced water replenishment and need for water for exploitation (m³ per metric ton of treated ore).

I think the following should be done:

1. Describe: In the chapter 5. Results of Evaluation of Application of Dewatered Tailings Methodologies at Large Scale Mining Study Case:

Costs are evaluated on the basis of water usage relative to the production  efficiency of the mine. In copper ore deposits where the quality of ore grade is low, the cost of water used per unit weight of metal obtained is high. Therefore, mining companies have to as-sess the cost effectiveness of using brackish or desalinated water. As a re-sult, mining companies are attempting to improve the efficiency of their water use in operations, by reducing water losses due to infiltration, evaporation or effluent generation.

• Please, all this needs to be clarified. Other parameters that affect the cost of production, ie the flotation process, should also be mentioned. Where the quality of the ore is low with metal content, of course the flotation process is burdened with higher costs. What about the combination of flotation reagents for specific cases?    

This has been given careful consideration and there are now 2 new references.

• List at least a few methods of waste treatment options including re-flotation when it comes to high quality minerals   

Done, Added

1.  Figure 13. Schematic view of mining project with desalinated water use

- Write the meaning of the mark on the picture and fix the picture 

This has been corrected

1. Taking into account the reasons announced above exist economic and environmental drivers to: (i) consider the conversion to thickened/paste or tailings/filter cake disposal technology, and (ii) consider the supply of sea water for mining processes. These aspects will be the new design and operation trends of Greenfield and Brownfield mining proјеct

- Explain which of the following procedures has comparative advantages and why

 Taking into account the reasons announced above in this article,exist economic (cost savings) and environmental (less water use and community approval) drivers exist in de-sert areas of Chile and Peru to: (i) consider the conversion to thickened/paste or tail-ings/filter cake disposal technology, and (ii) consider the supply of sea water for mining processes. These aspects will be the new design and operation trends of Greenfield and Brownfield mining projects.

Tailings Dewatering Technologies have comparative advantages, because is possible to save cost and have les water use and community approval. Added to the text in the article.

1. Although the development of thickening and filtration technologies has advanced significantly in recent years, more research / studies are needed to understand their behavior, focusing on achieving good performance in higher production with different tailings particle size distributions.

- Explain why. There are a number of manuscripts on the influence of particle size on flotation efficiency

 This show the high variability of the characteristics (particle size distribution and mineralogy) of treated ore in the grinding and flo-tation process in the metallurgical plants.. Added to the text in the article.

1. Figures 3 and 4 show typical water flows in a mill and a thickening plant and a tailings dump in a mining project.

      - Text in pictures to be in Times New Roman, or cite literature. This should be   harmonized in the other pictures as well

All figures have been checked and harmonized as required.

Best regards

Thank for your comments and suggestions.

Carlos Cacciuttolo Vargas

Author Response File: Author Response.docx