Sulfur Determination in Coal and Coke

Importance of Sulfur Determination in Coal and Coke

Total sulfur content is a critical parameter in the ultimate analysis of coal and coke. It directly affects fuel quality ratings, guides preparation and cleaning strategies, and forecasts potential sulfur emissions during combustion.

Study Objectives and Overview

This study outlines a standardized procedure for measuring total sulfur in coal and coke using the LECO S832 Series analyzer. The method follows ASTM D4239 (Method A) and demonstrates accuracy, precision, and compliance with recognized standards.

Used Instrumentation

• LECO S832 Series Sulfur Analyzer (including S832DR variant)

Methodology and Procedure

A representative sample is prepared per ASTM D2013. Moisture is determined separately by ASTM D3173, D7582 or ISO 11722 for dry-basis calculations. Blanks are run to characterize background sulfur. Calibration uses reference materials (LECO, NIST) in 0.25 g portions over three replicates. Key instrument parameters include a furnace temperature of 1350 °C, a 20 s lance-on delay, nominal blank mass of 1.0000 g, and integration times from 90 s to 360 s. Auto-range mode is applied in S832DR models with lower and upper limits of 800–950 µV.

Main Results and Discussion

Typical dry-basis results for NIST and LECO coal/coke standards show average sulfur recoveries within 0.01–0.03 % of certified values and standard deviations below 0.02 %. Both S832 and S832DR deliver consistent precision across low (0.46 %), medium (1.48 %), and high (5.70 %) sulfur levels, confirming method robustness.

Benefits and Practical Applications

• Rapid and reliable sulfur quantification for quality control in mining and power generation
• Compliance with ASTM and ISO standards for regulatory reporting
• Support for process optimization in coal cleaning and blending operations
• Emission potential assessment for environmental permitting and monitoring

Future Trends and Potential Applications

• Integration with automated sample handling for higher throughput
• Coupling with data analytics platforms to model emissions and fuel performance
• Development of portable or miniaturized sulfur analyzers for field use
• Expansion to multi-element analysis by combining with other detectors

Conclusion

The LECO S832 Series provides a validated, high-precision method for total sulfur determination in coal and coke. Its alignment with ASTM D4239 ensures reliable results for quality assurance, regulatory compliance, and emissions control.

Reference

• ASTM D2013 Standard Practice for Preparation of Coal and Coke Samples
• ASTM D3173 Standard Test Method for Moisture in the Analysis Sample of Coal and Coke
• ASTM D4239 Standard Test Method for Sulfur in the Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace
• ISO 11722 Solid Mineral Fuels—Determination of Total Moisture