Variability in Metallurgical Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR): An Experimental...

Area of Science:

• Materials Science
• Chemical Engineering
• Metallurgical Engineering

Background:

• Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR) are crucial for blast furnace efficiency.
• Variations in CRI and CSR results occur between laboratories despite standardized methods.
• Consistent coke quality is essential, influenced by coal blend and coke oven parameters.

Purpose of the Study:

• To develop and validate a novel laboratory sample holder for improved coke reactivity testing.
• To compare the established Nippon Steel Corporation (NSC) method with the new sample holder method.
• To investigate factors influencing CRI and CSR variability and optimize testing procedures.

Main Methods:

• Development of a unique laboratory sample holder for coke reactivity testing.
• Comparative analysis of the NSC test method and the newly developed sample holder method.
• Repeatability tests on coke samples with varying reactivity to study CRI and CSR correlations.
• Analysis of the influence of the number of coke pieces on test sample optimization.

Main Results:

• The developed sample holder demonstrated improved consistency in CRI and CSR testing.
• Coke reactivity was found to be highly dependent on the reaction of individual coke pieces.
• A variation of ±2 points in CRI/CSR readings does not significantly impact overall coke quality assessment.
• Optimization of coke bed height was explored by analyzing the effect of sample size.

Conclusions:

• The novel sample holder enhances the reliability of CRI and CSR measurements.
• Understanding the role of individual coke pieces is key to accurate reactivity assessment.
• The study provides insights into minimizing discrepancies in CRI/CSR values for consistent coke quality control.
• Optimized testing protocols contribute to more efficient blast furnace operations.