Application of the Flotation Tailings as an Alternative Material for an Acid Mine Drainage Remediation: A Case Study of the Extremely Acidic Lake Robule (Serbia)
, Srećko R. Stopić 3 and Željko Kamberović 4Round 1
Reviewer 1 Report
The manuscript describes the removal of some taels using flotation tailings. The Acid water containing several metals are in Serbia. The manuscript is suitable for metals, but some points should be improved.
1) In introduction, before the end of last paragraph in Introduction, You need to mention the motivation to this paper because there are some problems.
2) In software analysis, more information should be inserted. What information can we know? These should be inserted to Introduction and R&D.
3) Can you add the flow of the treatment as a Scheme?
4) In eq. 5) this equation include the dynamic information, in line 269 and 270 but the analysis of software includes the equilibrium information, isn't it?In your system, can you explain all the data based on equilibrium?
Author Response
Dear Reviewer, thank you very much for your Support and excellent remarks. We are sending our answers and attached new improved Version.
1) In introduction, before the end of last paragraph in Introduction, You need to mention the motivation to this paper because there are some problems.
- The high motivation of the research is not only to investigate the ability of flotation tailings to neutralize and purify water collected from the acidic Lake Robule, but also to remove iron in order to prepare a solution for recovery of valuable elements such as copper, gold, aluminum and silver in our future work. In order to predict the behavior of metals and especially its precipitation, the geochemical software will be tested and discussed with experimental results.
2) In software analysis, more information should be inserted. What information can we know? These should be inserted to Introduction and R&D.
-2.6. Simulation of metal precipitation using PHREEQC software
..An individual simulation was made for each defined time during the experiment according to the measured values of pH and the concentration of metals as input values for the calculations. Water volume, solid to liquid ratio and temperature, as constant parameters during the experiment, were also input values for the calculation. Saturation indices (SI) are defined as the logarithm of the ratio of the ion activity product (IAP) to the solid solubility product (Ks), equation 1.
3.5. Results of the PHREEQC software simulation of the water Treatment (R&D)
Results of the treatment simulation obtained by the PHREEQC program are given in Table 5. The results are based on the measured concentrations of elements and pH values of obtained solutions over time, as well as on defined water volume (50 mL), solid to liquid ratio (15%) and temperature (18°C) as constant values during the experiment. The results are presented in the form of calculated saturation indices (SI) of corresponding mineral phases.
3) Can you add the flow of the treatment as a Scheme?
es, we did, Figure 2
4) In eq. 5) this equation include the dynamic information, in line 269 and 270 but the analysis of software includes the equilibrium information, isn't it?In your system, can you explain all the data based on equilibrium?
This eq. 5) includes the dynamic information about formation of goethite but the analysis of software includes the equilibrium information, where maximal possibility for precipitation was in case of the hematite. Generally, as shown in Table 5, an increase of time and pH-Values increases possibility for the precipitation of iron hydroxide, goethite and hematite with different values of calculated saturation indices (SI). In case the other elements such as zinc, cadmium, lead, manganese these SI-values are negative with small possibilities for precipitation.
Reviewer 2 Report
The article entitled "Application of the flotation tailings as an alternative material for an acid mine drainage remediation: a case study of the extremely acidic Lake Robule (Serbia)" is an interesting manuscript that provides a solution for the acid mine drainage in the Lake of Robule (Serbia). The problem was adequately set and defined, the background is adequate and provides information about practices to solve the problem of the acid mine drainage in Lake Robule and other places using different techniques. And the results are clearly presented, and the conclusions are supported on them.
The operation and analyses conditions are clearly described and detailed.
Is the mine still in operation? Do they use some technology nowadays to minimize the generation of acid mine drainage?
In Table 7 when you indicate “/” in the table for the national discharge limits, what do you want to say: not defined or zero for the corresponding values?
Are there any plans for the application of the results of your research?
Author Response
Dear Reviewer, thank you for your Support and nice remarks. We are sending our answers and attached new Version.
Is the mine still in operation? Do they use some technology nowadays to minimize the generation of acid mine drainage?
The mining operations started in 1963; and since then 378 million tons of flotation tailings have been deposited on a large dump. Flotation tailings samples were dug out from cubes of 0.04 m3 volume (0.2·0.2·1 m) at 25 equidistant spatial locations (distance between locations was 50 m) forming square-shaped network, and put in the separate bags. In the laboratory, composite sample was prepared by quartering method. Regarding to Technology innovation in the field of minimization of Generation of acid mine Drainage, we have to Point out, that there is no some activities in this direction in this mining right now in Serbia. Because of this Situation, we did not write about it.
In Table 7 when you indicate “/” in the table for the national discharge limits, what do you want to say: not defined or zero for the corresponding values?
-"I" means not defined
Are there any plans for the application of the results of your research?
We inserted our answers in conclusion:
Our future activities shall be performed in order to propose a continuous neutralisation process for an application of the flotation tailings as an alternative material for an acid mine drainage remediation. Also, this methodology would be studied in scale-up condition, in order to obtain more realistic data on the consumption of flotation tailing amount and percent of acid mine water
Reviewer 3 Report
Research keywords - in my modest opinion could be improved with key words linked to "surface water", "polluted site remediation", or similar, indeed now the keywords are too much focused on metals and materials.
To show a map of Serbia with the locations of the two sites (Copper mine Majdanpek and extremely acidic Lake Robule) could help the understanding the sustainability of the remediation process.
Lines 204 and 225 - could be that the authors mean "higher H+ concentration" instead of " higher pH?
The authors say that the results of there "research are a step further in implementation of principles of the sustainable development including minimization, treatment and reuse of waste within the same industry." I suggest to get stronger this statement with a tentative estimation of the volume (or mass) of the flotation tailings necessary for the an active treatment of AMD. Also to show a map of Serbia with the locations of the two sites (Copper mine Majdanpek and extremely acidic Lake Robule) could help the understanding the sustainability of the remediation process.
Author Response
Dear Reviewer, thank you very much for your Support and nice remarks. Attached we are sending our answers:
Research keywords - in my modest opinion could be improved with key words linked to "surface water", "polluted site remediation", or similar, indeed now the keywords are too much focused on metals and materials
.We added: polluted site remediation, synergy of processes
To show a map of Serbia with the locations of the two sites (Copper mine Majdanpek and extremely acidic Lake Robule) could help the understanding the sustainability of the remediation process.
We did it, as shown at Figure 1
Lines 204 and 225 - could be that the authors mean "higher H+ concentration" instead of " higher pH?
Yes, we changed it
The authors say that the results of there "research are a step further in implementation of principles of the sustainable development including minimization, treatment and reuse of waste within the same industry." I suggest to get stronger this statement with a tentative estimation of the volume (or mass) of the flotation tailings necessary for the an active treatment of AMD. Also to show a map of Serbia with the locations of the two sites (Copper mine Majdanpek and extremely acidic Lake Robule) could help the understanding the sustainability of the remediation process.
-We inserted our answers in conclusion:
Our future activities shall be performed in order to propose a continuous neutralisation process for an application of the flotation tailings as an alternative material for an acid mine drainage remediation. Also, this methodology would be studied in scale-up condition, in order to obtain more realistic data on the consumption of flotation tailing amount and percent of acid mine water
