Geochemical Response of Surface Environment to Mining of Sn-Pb-Zn Sulfide Deposits: A Case Study of Dachang Tin Polymetallic Deposit in Guangxi

Round 1

Reviewer 1 Report

In the mining activities, solid polymetallic sulfide mines are the important environmental pollution sources. And, environmental pollutions have been improved further in the ore dressing and smelting processes, and heavy matters expand large area including atmosphere. So, it is an important to kept environmental health. For this target, to understand the heavy metal conditions in the different environmental mediums is the first step. In this manuscript, authors studied the different medium environmental pollution in detail caused by polymetallic sulfide mine mining activities at the Chehe Town in Guangxi, it is an important for the environmental evaluation this mine area.

There are some questions:

1.         “Due to continuous uplifting of the crust and downcutting of the riverbed, heavy metal pollution in the sediment has limited effect on the soil near the river.”, it is a long geological time, and no measured by short time, that means, this phenomenon can’t be considered in the human environmental pollutions.

2.         Sulfide can make water acid so that to corrode the carbonate in the karst areas, and this is a kind of environmental question. Another, polymetallic sulfide mine in this MS is in the mountain, enormous heavy metal pollutants can’t influenced mine area owing to strong runoff and carbonate corroding, but these heavy metals maybe influence the downstream area somewhere, so, it is a question to understand this mine how to influence downstream area, and how far, how to influence.

3.         It is best to add the background description of mining and smelting, and which kinds of minerals of this polymetallic sulfide mine? How to exploit and methods? Whether or not is there tailings ponds? How to deal tailings ponds, waster water, waste residues, etc? pouring these matter into Diaojiang River directly or after dealing?

4.         “The remaining 3 L of each sample was acidified with HCl to analyze concentrations of Cd, Pb, Zn, and other heavy metals.”, what’s kind of HCl? And how much the metalbackground concentrations?

5.         It is best to describe the analysis process, including devices, items, how to analyze simply, what are the standard matters? Why is X-ray fluorescence spectrometry (XRF) used and what items to analyze?

6.         In the Table 1, the best sequence is min, max, mean. And references must note.

7.         How to collect the air dustfall samples, and sites？ The analysis results must correspond with the sample sites.

8.         It is best to mark the different background metal concentrations in the Figure 4. And, why are the Cd, Zn, Pb concentrations in the upwind (-7, -3km) higher than that of downwind? What is the reason that there are low all metal concentrations in the downwind 3km site?

9.         “Based on the mineral compositions of various media (Fig. 5), the ore is mainly composed of primary sulfide minerals such as sphalerite, pyrite, and pyrrhotite.”, how to find these minerals from the figure 5? Do the figures in the figure 5 observe from slices, or others? Low pyrite in the sediment can be found in the XRD figure, but can’t be found in the tailings, and how to demonstrate it is pyrite（FeS）? How about metal the background values at this area?

10.      “Tailings and sediment that are exposed to hypergene conditions for a long time, in addition to retaining some primary sulfide minerals, are mainly composed of secondary minerals such as quartz, calcite, kaolinite, goethite, illite, and gypsum.”,is quartzsecondary mineral?

11.      “The tailings had undergone the processes of mining, smelting, and open storage, the heavy metals were mainly in the form of oxides, and the potential risk was greatly reduced compared with that of ore.”, in this MS, what is “tailings”? and what is tailings in generally? Form table 3, heavy metals are very high in the tailings.

12.      “The migration and transformation of elements during the supergene process can be characterized by ΔC.”, it is best to explain ΔC at the first appearing.

13.      Is the results of Figure 6 this MS’s results or does cite from other author’s results? No downstream samples in this MS, or far downstream samples.

14.      In the discussion, some general concepts have been described, it is not to discuss the data from this MS, and not make environmental evaluation by these data also. It is best to rewrite this part.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript entitled “Geochemical response of surface environment to mining of Sn-2 Pb-Zn sulfide deposits: A case study of Dachang tin polymetallic deposit in Guangxi” by Bo Li et al., presents a results of geochemical, mineralogical, and statistical investigation of Pb/Zn mine tailings, mine drainage, stream sediments, soil, dust, and crops. The authors conducted a detailed study of the sample composition performed to explore the geochemical response of the surface environment to mining and smelting of metal sulfide deposits and to assess the environmental hazard of tailings. The work carried out and the results obtained are very important for understanding the processes of metal release and their migration from tailings.

The manuscript is well-written, having a clear structure.

            Therefore, I recommend the acceptance of this manuscript in the “Water”. Yet, the authors should address some minor suggestions, listed below.

Subsection 2.3. Analysis methods. Please provide information about sample preparation of dust, stream sediments, crops.

L 164-165. The first two sentences are not results, but a description of the study object.

L 168. Reference to Fig. 2 comes before the reference to Table 1, while in the text Fig. 2 is shown after the Table. 1.

Table 1 (and others). The numbers in the table are given with excessive precision. The analytical error is 5%. For example, 5% of 3173.91 would be 159, i.e. plus or minus 159. The real value will be 3200.

L 193-195. It says: Migration of As, Cd, Pb, Zn, and other heavy metals in the atmosphere showed similar geochemical behaviors and variations along the wind direction.

However, if you look at Fig. 4, we see that zinc and cadmium are distributed similarly, while lead and arsenic have large differences in migration

Formula F1 should be shown in the Methods section (editor's discretion).

Table 3. Please, explain the meaning of the coefficients.

In general, the text is written in an interesting way, the manuscript is well illustrated, the conclusions are proved by a large amount of factual material.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

I have carefully reviewed the manuscript titled "Geochemical response of surface environment to mining of Sn-Pb-Zn sulfide deposits: A case study of Dachang tin polymetallic deposit in Guangxi" (water-2295429). The authors present a detailed analysis of the geochemical distribution, migration, and transformation behaviors of Cd and other heavy metals in and around the mining area, and their potential impacts on the surface environment. The study highlights the need for monitoring and controlling the risks associated with sediment transport, conducting treatment, and adjusting crop planting to manage heavy metal pollution.

However, there are some minor issues that should be addressed before the manuscript can be accepted for publication. I have detailed my comments and suggestions below:

1-      Line 12: replace (Rational) with (The rational)

2-      Line 14: replace (metal) with (metals)

3-      Line 26: replace (metal) with (metals)

4-      Line 27: replace (has) with (have)

5-      Line 132: replace (Fig) with (figure)

6-      Line 204: what do you mean by each element was calculated according to (F1):???

7-      In table 3 remove the Chinese world near to pH

8-      Line 279: what do you mean by supergene process can be characterized by ΔC:???

9-      All figures in this article are highly relevant, but unfortunately, the resolution is quite poor, making it difficult to clearly discern the details. A higher resolution would greatly enhance their impact.

10-  I recommend that the authors provide a more comprehensive caption for all figures that includes a clear label and short description of each image. This will help readers understand the figures and their relevance to the study findings.

11-  Figure 5. Label each image and provide a short description of each image

12-  The authors need to provide more details about the analytical methods used in this study, particularly the ICP-MS, XRF methods. The description of the instrument settings, sample preparation, data acquisition, and calibration procedures. Without this information, the reliability and accuracy of the results are uncertain.

13-  The tables in this manuscript are useful for conveying the study findings, but the lack of a complete data set for Tables 1-5 limits the usefulness of the information. I encourage the authors to provide a complete data set to allow for better interpretation of the results.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors have reviewed this MS in detail, and I have not more questions. I agree most of them.