Analyzing the metallization of DRI for process optimization using ARL X’TRA Companion X-ray Diffractometer

Importance of the Topic

Direct reduced iron (DRI) offers a low-carbon alternative in steel production by reducing iron ore in its solid state with natural gas or hydrogen, aligning with global efforts to lower greenhouse gas emissions and enabling the manufacture of green steel.

Aims and Study Overview

This application note assesses the performance of the Thermo Scientific ARL X'TRA Companion X-ray diffractometer for quantifying metallization in DRI. The goal is to demonstrate how rapid, accurate XRD analysis can optimize reduction processes and ensure product quality.

Methodology

• Selection of six DRI samples covering a range of metallization levels, with reference values obtained by XRF and wet chemical analysis.
• Sample preparation involved manual pressing into top-loading cups and measurement in reflection mode using Co Kα radiation, spinning, and 10-minute scan times.
• One-click Rietveld refinement was performed in Profex, including crystalline gangue phases, to determine Fe metallic, Fe total, and metallization percentages.

Instrumentation

The ARL X'TRA Companion is a benchtop XRD system featuring a θ/θ goniometer in Bragg-Brentano geometry, a 600 W Cu/Co X-ray source, divergence and Soller slits, a variable beam knife to reduce air scatter, an integrated water chiller, and a solid-state pixel detector for rapid data acquisition. It offers automated Rietveld quantification and direct LIMS connectivity.

Results and Discussion

Quantitative XRD results correlated strongly with reference data: Fe metallic (R² = 0.99), Fe total (R² = 0.92), and metallization (R² = 0.98). Systematic biases ranged from 1.17 to 7.22 and proportional biases were close to unity. The standard error of estimate for metallization was 2.53%. Minor discrepancies are attributed to amorphous gangue phases not detected by XRD.

Benefits and Practical Applications

• Rapid and accurate metallization quantification in seconds.
• User-friendly one-click Rietveld analysis reduces operator training time.
• Continuous monitoring supports real-time process optimization and cost savings.

Future Trends and Applications

Advances in hydrogen-based reduction, in-situ XRD monitoring, greater automation, AI-driven pattern recognition, and tighter LIMS integration will further enhance sustainable steel production and quality assurance.

Conclusion

The ARL X'TRA Companion XRD system delivers fast, reliable metallization analysis for DRI, supporting stringent quality control, process optimization, and the transition toward greener steel manufacturing.