Identification of the Elemental Composition of Granulated Blast Furnace Slag by FTIR-Spectroscopy and Chemometrics

Round 1

Reviewer 1 Report

This work presented a new method for composition measurements of blast furnace slag. However, some problems are existed

1. In ironmaking plants, the composition of blast furnace slag can be calculated using mass balance between the raw materials (sintered ore, coke and so on) and liquid iron, slag. It’s a fundamental work in ironmaking plant. Thus, the novelty of this work is not been presented.  

2. In Lines 91-93, authors emphasized that SEM is not suitable for composition measurements, because it cannot be “on-line” used. However, slag tapping of blast furnace is intermittent, the typical time interval for slag tapping is hours. Thus, continuously measurements are unnecessary. In addition, SEM-EDX can test nonconducting samples, only a simple sputtering coating (Au, Pt, or C ) is required.

3. In Line 100, authors emphasized that the “quantity” problem and limitations in measuring lighter elements limited the use of XRF. However, the sample quantity for FTIR-Spectroscopy method required similar sample quantity. The key point should be the uniformity in sample preparation, not the quantity. Besides, as light elements such as Li, B, F, Na, K are harmful for refractory of blast furnace, ore or fusing agents containing those light elements are severely restricted. Thus, XRF nearly can measure all typical elements in blast furnace slag.

4. In preparation of XRD samples, the particle size is a key point, more details of sample preparation are required. Moreover, in Figure 1 (PAO<<Mechel>>), only one peak for each mineral is not allowed. As XRD is not suitable for minor mineral identification. A SEM-EDX measurement is suggested for crystal confirmation in glassy slag. 

5. More specific details of EDX measurements, especially sample preparation procedure, EDX spectra (including images with labeled point or area that detected), and composition results of selected 4 samples.

6. Typically, aluminum oxide is a primary component in blast furnace slag. However, the 4 slags presented in this work contained no Al. I am wondering if authors used new slag-system for blast furnace operation? Or for other reasons.

7. Introduction, experimental method, and especially the conclusion section should be revised for a better logicality.  

Author Response

Thank you for your detailed comments and review of our work. The answers are provided in attached file.

Author Response File: Author Response.docx

Reviewer 2 Report

Granulated blast furnace slag is useful for many applications. A fast chemical composition analysis is helpful for identify the optimized application area of BF slags. In this study, the authors developed good calibration models for determining the elemental composition of blast furnace slag from infrared spectra by multivariate analysis. They analyzes the application of Fourier transform infrared spectroscopy (FTIR) and chemometrics methods to develop calibration models for identifying pelletized slag by elemental composition. Multivariate regression methods and data of elemental composition results by EDX method were used to develop calibration models for determining elemental composition of granulated blast furnace slag. The use of PLS calibration models for rapid and nondestructive determination of the quantitative content of components of the composition of granulated blast furnace slag has been proposed. This is a nice work.

 

Comments:

1.     The literature review is a good work. References are up-to-date. Some references from top metallurgical journals e.g. metallurgical and materials transactions B may be referred.

2.     Morphology and phase composition may play a role in the composition determination. However, this requires more samples.

3.     A problem is the details of calibration model or parameters might be elaborated. Than the readers may know how to use the model.

4.     We look forward for the models on convertor slag, EAF slag etc.

 

References,

Ref 2, Author 1 Author 2 should be deleted.

Ref 19, revised manuscript? Should be deleted.

The paragraph font of reference may be revised to meet the journal requirements.

Author Response

Thanks for your commentaries and appreciation of our manuscript. The comments are presented in attached file.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

In Figure 1 (c) and (d), the EDX curves are different. However, the presented compositions in those Figures are the same. Please check the data.  Besides, if possible, please add other main peaks of Ca2MgSi2O7 in Figure 2 (PAO<<Mechel>>).

Author Response

Thanks for your additional comments. This were a technical mistakes. Fig. 1 (d): EDX-spectra corresponding to the true sample graph has been added. Other phase peak markers added in Figure 2.

Author Response File: Author Response.doc