Arsenic Removal from Arsenopyrite-Bearing Iron Ore and Arsenic Recovery from Dust Ash by Roasting Method
Round 1
Reviewer 1 Report
Please consider the comments and suggestions in attachedfile.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 1 Comments
Thanks very much for your and the reviewer’s valuable comments to our manuscript ‘Arsenic removal from arsenopyrite-bearing iron ore and arsenic recovery from dust ash by roasting method’. We have revised the manuscript according to the recommendations by the reviewers and editor. The changes are emphasized by highlighting in the revised manuscript using the track changes mode in MS Word.
The revisions are incorporated in the revised manuscript and the Reply to the Reviewers is given below.
Best Regards!
Manuscript ID: processes-604297
Point 1: Page 3: Changing the word ‘indoor’ into ‘room’.
Response 1: Thanks for the valuable comment. According to the reviewer’s suggestion, I have made corresponding amendments.
Point 2: Page 3, ‘2.2 Experiment on recovery of arsenic by roasting dust ash’: The arsenic recovery experiment by roasting in the atmosphere of air, anaerobic and reducing was carried out with 10% As2O3 powder in the dust ash.
Replace this sentence with ‘The arsenic recovery experiment by roasting was carried out in two different atmospheres with 10% As2O3 powder in the dust ash’.
Response 2: Thanks for the valuable comment. According to the reviewer’s suggestion, The sentence has been changed to ‘The arsenic recovery experiment by roasting was carried out with two different atmospheres with 10% As2O3 powder in the dust ash’.
Point 3: Page 4, ‘3. Results’: The arsenic content in the ore after roasting at different temperatures is listed in Table 3.’ move to the end of the chapter.
Response 3: Thanks for the valuable comment. According to the reviewer’s suggestion, I have moved this sentence to the end of this chapter.
Point 4: Page 5, ‘4.1. Thermodynamic calculation of mixied ore subjected to roasting’: Delete the word 'caculation' in the text.
Response 4: Thanks for the valuable comment. According to the reviewer’s suggestion, I have delete this word in this text.
Point 5: Page 5, ‘4.2. X-Ray diffraction analysis of the roasted ore and dust in different atmospheres’: write 'bottom' clearly in the text.
Response 5: Thanks for the valuable comment. According to the reviewer’s suggestion, I have supplemented ‘Figure 5a bottom’ in this text.
Point 6: Page 6, ‘4.3. Mechanism research on arsenic removal by roasting method and scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis’: what about AlAsO4? Si, Mn are also in chemical composition. please comment.
Response 6: Thanks for the valuable comment. As can be seen from Figure 6c, Arsenic probably exists as FeAsO4. However, the formation of AsAlO4 also was found in Figure 5. As for Si and Mn, they are in the presence of SiO2 and manganese oxide. In a word, Arsenic remains in the form of arsenate. Therefore, the article should be revised as ‘Figure 6c and 5 show that the arsenic in the roasted ore is present as FeAsO4 and AlAsO4 at 800 °C, respectively’.
Point 7: Page 7, ‘Table 4. Chemical composition of the raw ore and roasted ore’: keep the entire table on the same page
Response 7: Thanks for the valuable comment. According to the reviewer’s suggestion, the table will be displayed on one page later.
Point 8: Page 10, ‘5. Conclusions’: It can be deduced from the xrd diagram of ore roasting in a nitrogen atmosphere that an amorphous substance has been formed. Is this true and if so, has a chemical analysis been done?
Response 8: Thanks for the valuable comment. From the XRD spectrum, it can be seen that amorphous substance was not found in roasted ore, but a small peak of amorphous substance appeared in the roasted dust ash, which may be the residual carbon added in the dust ash during reduction roasting. As this paper focuses on the recovery of arsenic, so arsenic in dust was analyzed by chemical analysis, but the other substances have not been done by chemical analysis.
Author Response File: Author Response.pdf
Reviewer 2 Report
Introduction: One more point to add as to why it's so unfavourable: As in any metal concentrate from a marketing stance means the mining company take a hit in terms of penalties when selling, or simply, the customer can refuse the concentrate.
Materials and methods: Just to be clear and I think you need to write more detail in the method... mixed ore is just that? A synthetically derived sample containing the mineralogical components as shown in Table 1? How was the mixed ore broken up to pass 75 mesh? What are 'mineral balls'? Are they ceramic balls used as seeds? If so, you may need to be more specific here. Page 3, you need to specify what 'various tests' are right there. Can you please make Figure 2 larger.
2.3, what XRD equipment was used and what software? Siroquant? What SEM was being used?
4.1 spelling 'mixied'
Can you comment how reliable is was to obtain EDS data from an SE SEM sample? Did you find the data to be consistent chemistry or has there been inferred interpretation? It's just not all that easy normally. Maybe consider a specific surface chemistry technique next time? Just a suggestion.
Conclusion:
point one - can you please rearrange the English in this sentence.
Just to add extra to the paper, is there any opportunity to elaborate on case studies at all? It will provide a different perspective on why you embarked on this research.
Author Response
Response to Reviewer 2 Comments
Thanks very much for your and the reviewer’s valuable comments to our manuscript ‘Arsenic removal from arsenopyrite-bearing iron ore and arsenic recovery from dust ash by roasting method’. We have revised the manuscript according to the recommendations by the reviewers and editor. The changes are emphasized by highlighting in the revised manuscript using the track changes mode in MS Word.
The revisions are incorporated in the revised manuscript and the Reply to the Reviewers is given below.
Best Regards!
Manuscript ID: processes-604297
Point 1: Introduction: One more point to add as to why it's so unfavourable: As in any metal concentrate from a marketing stance means the mining company take a hit in terms of penalties when selling, or simply, the customer can refuse the concentrate.
Response 1: Thanks for the valuable comment. As arsenic reduces the quality of raw materials, affects the extraction of metal, interferes with the purity of the product, and poses serious environmental hazards, so arsenic is an unfavorable element in metallurgical processes. But the price of arsenic-bearing iron ore is cheaper than that of high-grade iron ore, moreover, the total amount of high-grade iron ore is decreasing year by year in the earth, and arsenic-bearing ore needs to be comprehensively utilized through ore blending. Therefore, some domestic iron and steel enterprises have used these arsenic-bearing iron ore. Relevant content has been added to the introduction.
Point 2: Materials and methods: Just to be clear and I think you need to write more detail in the method... mixed ore is just that? A synthetically derived sample containing the mineralogical components as shown in Table 1? How was the mixed ore broken up to pass 75 mesh? What are 'mineral balls'? Are they ceramic balls used as seeds? If so, you may need to be more specific here. Page 3, you need to specify what 'various tests' are right there. Can you please make Figure 2 larger.
Response 2: Thanks for the valuable comment. According to the reviewer’s suggestion, the research method is supplemented in the article, Including but not limited to equipment type and experimental procedures.
In order to facilitate the detection and analysis of XRD and EDS, the arsenic content was increased by mixing 90% arsenic-bearing iron ore with 10% arsenopyrite.
Mixed ore was crushed by F77-1 sealed sample grinder for 1 minute, then screened by 75 mesh sieve. The ore powder larger than 75 mesh was crushed again until all power were less than 75 mesh, and then the crushed power were mixed. Relevant content has been added to the ‘materials and methods’.
Mixed ore was blended with water to make iron ore balls with a diameter of 10 ± 2 mm. The ‘mineral balls’ are ‘iron ore balls’ made of mixed ore, or pellets made of mixed ore. In order to avoid confusion, mineral balls have been replaced by ‘iron ore balls’ in the article.
‘Various tests’ refer to the following ‘2.3 Sample analysis and testing’, including XRD, ICP, SEM and EDS.
Figure 2 has been enlarged appropriately.
Point 3: 2.3, what XRD equipment was used and what software? Siroquant? What SEM was being used?
Response 3: Thanks for the valuable comment. The phase composition of iron ore was evaluated by PANalytical XPert PRO MPD X-ray diffraction (XRD) with Cu target, K radiation and 40 kV operating voltage, and the software is ‘Highscore Plus’. The chemical component of roasted ore was determined by IRIS Advantage Radial inductively coupled plasma atomic emission spectrometry (ICP-AES) and the physicochemical properties of the roasted ore were analyzed by FEI Nova NanoSEM400 scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). Relevant contents have been supplemented to ‘2.3 Sample analysis and testing’.
Point 4: 4.1 spelling 'mixied'.
Response 4: Thanks for the valuable comment. According to the reviewer’s suggestion, Word spelling errors have been corrected to ‘mixed’.
Point 5: Can you comment how reliable is was to obtain EDS data from an SEM sample? Did you find the data to be consistent chemistry or has there been inferred interpretation? It's just not all that easy normally. Maybe consider a specific surface chemistry technique next time? Just a suggestion.
Response 5: Thanks for the valuable comment. to a certain extent, EDS data obtained by scanning electron microscopy can reflect the migration and change of arsenic in ore. During the experiment, many SEM images were taken for each sample, and more EDS data were obtained for each image than those points and data in the image. In this paper, the representative picture of every sample was selected, and its data of each point with different components, and the duplicate or similar data of components were excluded, which ensures that the results are objective, complete and concise.
Point 6: Conclusion:
point one - can you please rearrange the English in this sentence.
Response 6: Thanks for the valuable comment. According to the reviewer’s suggestion, This sentence has been revised to ‘Arsenic in arsenopyrite-bearing iron ore can be removed by roasting method in air or nitrogen atmosphere’.
Point 7: Just to add extra to the paper, is there any opportunity to elaborate on case studies at all? It will provide a different perspective on why you embarked on this research.
Response 7: Thanks for the valuable comment. At present, the arsenic content in molten iron exceeds the standard due to the adoption of arsenopyrite-bearing iron ore in Egang Iron and Steel Company. Because the hot metal is reductive, it is difficult to remove arsenic by oxidation in hot metal. This is also the reason why the arsenic removal from ores should be done in this paper. It is of great value for the research on the large-scale application of arsenic-bearing iron ore in the future.
Author Response File: Author Response.pdf
