Numerical Investigation of Blast Furnace Operation with Scrap Charging

Round 1

Reviewer 1 Report

I suggest the following corrections before final publication:
1. a more detailed insight into the modelling of the chemical reactions and the energy of reactions to the thermodynamics of blast furnace operation
2. Figures 3 and 4 should be larger and an even clearer presentation would be achieved if they showed a deviation from the base case (100% sintering)
3. Some seemingly illogical results need to be explained in more detail (highlighted in the attached text)

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear author

 

This paper conducts a numerical simulations of scrap use in BF and considers the mitigation of CO₂ emissions. This is an important research for global warming. However, I think the explanation about the numerical simulation performed in the text is not enough. Please revise the following points.

 

1. (3 Model development)

There is not enough explanation about the model of numerical simulation. I think it is necessary to explain the chemical reactions and the boundary conditions of material input and output with particular consideration. Please explain the details of the model in the text or refer the paper that explains the details of the model.

 

2. (line 95)

The different porosity was used in cohesive zone, dripping zone, and deadman. Please explain how to define each area in this simulation.

 

3. (Table 4)

The ore rate and scrap rate for each case are listed but considering TFe = 56.3wt% written in the properties of sinter (table 1), the total amount of input Fe is less than 1 ton. Please check and correct the table.

 

4. (line 167)

Case E was judged as optimal condition from thermal efficiency and top gas utilization, but these values are affected by the reducing agent rate and blast flow rate. Since Case A and Case E use different RAR, I think other cases also use their respective RAR. Please explain in the text how to determine RAR. And, is the blast flow rate the same value in all calculations?

 

5. (table 5)

In the RAR of coke, cases A and case E had the same value for others. As an example of others, the reduction of SiO₂ is listed. But, since the ore rate is lower, I think Case E would have a smaller value than case A. Please explain the detail of RAR calculation.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thank you for your polite and quick response to my comments. And, I'm sorry for my overlooking the molten iron composition.
This paper was improve and have enough quality for publishing.