Study of Mineralogy and Metallurgical Properties of Lump Ores
Round 1
Reviewer 1 Report
This paper presents an interesting study of lump iron ore properties with some very nice SEM analysis along with metallurgical tests.
Publications on lump ore properties are relatively rare, however, the authors have missed a significant body of work carried out by other authors in this area. These should be reviewed, and if appropriate, discussed in comparison with the results found in this study. Are the results for ores A S J high or low compared to other results in the literature? Some suggested papers are:
* "Lump iron ore and sinter behaviour during softening and melting", ISIJ International, Vol. 51 (2011), No. 6, pp. 930–938
* "Thermal degradation of lump ore in the top shaft of blast furnace", AusIMM Iron Ore Conference, Perth, 2013, pp. 421-425
* "Influence of structural changes on the reducibility of iron ores", AIME-ISS Iron and Steelmaker, September 1991.
* "MAC lump properties study and plant performance at Baosteel stainless steel", 5th International conference on science and technology of ironmaking (ICSTI) 2009.
* "High Temperature Softening and Melting Interactions Between Newman Blend Lump and Sinter", ISIJ International, Vol. 61 (2021), No. 12, pp. 2944–2952
* "New techniques to measure softening and melting properties of mixed burdens of lump ore and sinter", 11th CSM congress 2017.
Experimental methods must be included - please add a brief overview of the method plus a reference to any standards used. Add this for bulk density, apparent density, open porosity, DI, RI, RDI and softening and melting. In particular for softening and melting, how are Ta, Ts, Tm and Td defined?
Please keep the order of the ores consistent between tables, e.g. A J S. Table 1 is the only one with ores in the order A S J.
The results in Fig 10 are interesting, however, it is not clear from the text or Fig that the open porosity is open porosity after heating in N2 at 900C. Please make this clearer.
The open porosity plotted in Fig 10 appears more useful to me than the micrographs in Fig 11. Fig 11 could be omitted.
Line 300; you mention an ore B. I assume this is a mistake.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript by Deqing Zhu and co-authors presents the mineral and physical characteristics of three types of lump ore. I am not familiar with similar studies so I am not able to judge if this number of samples is enough to publish as a separate paper. However, even if it is enough the methods section should be improved for the readers to appreciate the performed analyses. In detail the methods section is basically missing, no information is given on how chemical and physical properties were analyzed, conditions of XRD and SEM analyzes are not described, and the sampling protocol is not clearly presented. The results section should also be improved and all the text should be strictly linked to Figures. I have given many examples in the comments below when it was not done so. I would also work more towards clarity of conclusions, because as it is right now the paper reads as a gathering of separate sections. For now, the main conclusion “reasonable ratios [of the three types of lump ores]should be advised by optimizing the blast furnace burden structure to accomplish the objective of lower production costs and fewer carbon emissions” is unwarranted and not well argued. What proportions are advised and why?
Line 42 – Authors say “it is critical to conduct a systematic study on iron lump ores”, but the need to do so is not clearly explained. Ok, presently we have environmental problems with many issues, but why studying lump ore should solve any of these problems? As authors say lump ores are just one of many components used in iron smelting, why one is more important than the others? The need for studying lump ores should be more thoroughly addressed.
Line 47 – “In recent years, a large variety of researchers” – I think the word “variety” is not used correctly. How researchers can be various?
Line 51 – the sentence is unclear, and something is wrong with the cause-effect reasoning. In detail by writing “there is a lack of focus on the nature of the lump ore itself, due to the fact” the authors suggest that other researchers do not focus on the lump ore because it is important.
Line 63 – More information is required: Where was the chemical composition analyzed? What is TFe and how it was estimated? Why the composition does not sum to 100%? Are two decimal places significant?
Line 77 - More information is required: How were the physical parameters measured?
Line 95- I am confused with the number of samples analyzed. What do the authors mean by parallel samples? Why the ores were mixed? Why the samples were crushed? Please write this section more clearly.
Line 97 – What is “GB/T103221-2000” please give a better description and reference.
Line 135 – How was it possible to estimate proportions between minerals up to two decimal places? Please provide better statistics e.g. number of frames analyzed e.c.t.
Line 140 – “From the photos of mineral phases shown in Fig. 2~3, it can be seen that the hematite content was 42.56wt%” – I would not say that the exact content can be seen in photos. Please rephrase.
Line 143 – “it can also be observed that the surface of magnetite grains was slowly oxidized to generate martite, which was frequently coeval with minerals such as goethite and magnetite” – No, I could not observe what the authors describe in Fig. 2. First of all, I do not know where martite is supposed to be. Second, how I can judge that the oxidation was slow” – All the descriptions should be improved and better linked to the Figures. As a start, all the photos should be given alphabetical symbols and should be clearly referred to in the text (e.g. Fig. 2a)
Line 147 –“ in the form of dip” – I don’t know what the dip form is.
Line 148 – “formed coarse aggregates with well-developed grains” – Actually, the only microanalysis of magnetite shown in Figure 3 seems to crystallize at hematite boundaries.
Line 169 – “Particle sizes” – It is not clear what the particles are. Again, the description should be better linked to each photograph and not generally to Figures 4-5.
Line 181 – “S was identical to that of lump ore A” it was not identical, proportions are different. Also, Alumogothetite appears in Fig. 7, but it was not mentioned anywhere in the text or Tables.
Line 186 – “by goethite dehydration” or “largely improved in its reducibility” etc: these sentences are interpretations, this paragraph should be reserved for description only.
Line 190 – “Lump ore S had the most pores among the three lump ores, followed by lump ore A, and the most compact was lump ore J.” – this is a summary for all the analyzed lump ores, but it is mentioned in the paragraph on the lump ore S
Line 257 – “ J>A>S was the order of reducibility of lump ores from 258 high to low” – according to Figure 1o this sentence is not correct. A has the lowest reducibility.
Line 271 – “As seen in Fig. 11, the open porosity of lump ores at high temperatures was J>A>S in the order of high to low, which was consistent with the pattern in Fig. 10.” – I do not see this feature in Fig. 11 and I think that the second part of the sentence is not correct.
Line 299 – “The softening and melting performance of lump ores J and S was superior to that of lump ores A and B.” – First of all, an ore B was never mentioned and I do not understand where this interpretation comes from.
Line 318 – “the three types of lump ores had higher starting softening temperature and dropping temperature, narrower softening temperature interval.” – This is an unclear sentence, higher than what, narrower than what?
Figures should be improved:
Fig. 1 – if the 2theta is the same for all three plots, why the peaks for ore S and J are in different places? I think that something was misplaced during the figure preparation.
Fig. 3 – The scale bar should be better presented (as in Fig. 2), the Tables in the spectra pictures have many unnecessary arrows and space points. There is no need to present both Weight% and Atomic% information. Axes are not described. The caption is too short, it does not refer to spectra at all. I would not say that spectra present a local morphological information.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The revised manuscript is much improved and most of the points have been well addressed, with the addition of extra methodology and some additional references on lump iron ore properties.
One thing missing is a discussion, comparing the results of ores A, J and S to previously published results for other hematite / goethite iron ores. Please add some short discussion comparing results.
Author Response
Thanks for your kind reminders. We revised the sentence as follows:
“According to the Code for design of blast furnaceironmaking plant of china (GB50427-2008), the high-temperature metallurgical properties of three Malaysian lump ores are in accordance with the ironmaking industry standard. Therefore, an interactive test can be conducted to explore the reasonable proportion of furnace charge, so as to optimize the structure of blast furnace charge.[Ln311-315]；All in all, the comprehensive quality of the three lump ores meets industry standards‘’.[Ln323-324]
Author Response File: Author Response.pdf
