Innovative Transformation and Valorisation of Red Mill Scale Waste into Ferroalloys: Carbothermic Reduction in the Presence of Alumina
, Yuri Konyukhov 2, Kejiang Li 3, Kalidoss Jayasankar 4, Nikita Maslennikov 2, Dmitry Zinoveev 5, Jumat Kargin 6, Igor Burmistrov 7, Denis Leybo 8, Maksim Kravchenko 9 and Partha Sarathy Mukherjee 10Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors introduced a method to reduce the red mill scale waste and transform the waste to ferro-aluminum alloy. Please find my comments below.
1. In Materials and Experiment section, the authors determined three sets of red MS, graphite and alumina blends. In the set without alumina, the authors used 8g instead of 10g in the other two sets with alumina. I understand the authors referred to the work of Khanna et al., however, as a control group, the difference of graphite amount would bring up the question of the importance of graphite amount. I suggest the authors should clarify the key factor in this research is alumina not the graphite amount increase.
2. The Results section is confusing. The result is not consistent with the authors’ statement. The authors should have better explanation and connection between each set and temperature. For example, “Much higher levels of Al (5.7%) were detected in the metallic droplet. The results for the (20g red MS+20g Al2O3+10g C) heat treated at 1550ºC were found to be quite similar to those reported in Figure 5; these have been presented in the supplementary Figure S3.” (237-239), the supporting information Figure S3 only shows Al level of 1.3%, the (20g red MS + 20g Al2O3 + 10gC) at 1550 ºC is more similar to Figure 3.
3. The figures need improvement, e.g. the element table is too small in Figure 2 (a); two #2 in EDS spectra in Figure 5.
Author Response
Please see attached file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis work reports that a route for extracting iron from red MS and transforming it into ferro-aluminium alloys using carbothermic reduction in the presence of alumina. The red MS powder was blended with high purity alumina (Al2O3) and synthetic graphite (C) in a range of proportions. The carbothermic reduction of red MS-Al2O3-C blends was carried out at 1450ºC and 1550ºC under argon atmosphere for 30 minutes and then furnace cooled. Some questions should be answered.
1. XRD should provide standard card peaks and corresponding crystal planes.
2. The scale of SEM should be enlarged.
3. EDS is too small to see it clearly.
4. Just small experiment is difficult to support the conclusion, “This study has shown that red MS is a valuable material source, which could be transformed into ferro-aluminium alloys for utilization in a range of industrial sectors such as construction, automotive, infrastructure etc. in an economic, and environmentally sustainable manner.”
Comments on the Quality of English Languageit is ok.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe research paper was carefully written, and the issue is nicely presented, however, there are certain changes that must be made in order for the research to be more effective.
Page 1: write the afflilation without email and check the affliation no. 6
Page2 line 61: it is preferable to write the aim of the work in the end of the introduction
Page 2 line 66: “in MT; 39 MT global total” what does “ in MT “ mean ?
Page 2 line 95 : write the refernce number at the end of the sentence and check this in the rest of the text
Page 3 line 137: Explain the temperature at which the process was carried out as well as the temperature attained.
Page 4 line 156: mention the location with its Coordinatesز
Page 4 line 159: “surface area 8.79 m2/g” put the adsorption-desorption curve of BET for this specific surface area and in the rest of measured surface area as well
Page 5 line 198: “EDS and XRD have also been included in the figure” mention the no. of figure
Page 6 line 211: why the Si and O do not appear when the treatment was carried out at 1450 áµ’C
Page 7 line 218: “atop: correct it to “a top”
Page 9 line 244: I recommend that XRD be put with its own characterization as done in Figure 2.
Page 10 line 258: Explain the role of Al2O3 in the reduction process and how its presence lowered the reaction temperature.
Page 13 lines from 319 to 332: check the text format
Page 13 line 327: in the future work add the proper application for the produced material
Pagr 14, 15 and 16: check the format of the references NO. (1, 3, 13, 15, 16, 20, 22, 33, 35, 36, 37, 40, 42, 43, 44, 46, 51, and 53)
Comments on the Quality of English Language
Minor editing of English language required
Author Response
Please see attached file
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe document shows an interesting proposal on the recycling of iron mill scales from iron manufacture, which is one of the largest and most polluting industries worldwide. I recommend accepting this article, after some suggestions to the authors:
1. It is essential that in the introduction the authors emphasize the importance of commercial ferroaluminum alloys and the desired composition that justifies the development of experimental tests. The graph included in the supplementary material would serve to emphasize the importance of this study.
2. In the experimental development section, I think it is important to point out what the role of carbon will be in the mixture. From what I understood, it would be used only as a flux agent to lower the melting temperature of iron oxides. However, would the authors desire the formation of iron and aluminum carbides? How would this potentially impact the alloy's properties?
3. I suggest, if possible, trying to explain the low melting point of the ferroaluminum alloy found by the authors. Could it be a eutectite point found at this composition and temperature? Given the importance of this result, I recommend increasing the discussions in this section, perhaps supported by the Fe-Al phase diagram.
Comments on the Quality of English LanguageWritten English is fine. However, authors should avoid using expressions that do not belong to a technical document, such as very curious phenomena, line 278.
Author Response
Please see attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for Authorsaccepted
Comments on the Quality of English LanguageMinor editing of English language required
Reviewer 4 Report
Comments and Suggestions for AuthorsThe authors have addressed most of my comments. I recommend accepting it in its current version.
