Determination of Carbon and Sulfur in Metal-Bearing Ores and Related Materials (CS844)

Importance of the Topic

Determination of carbon and sulfur in metal bearing ores is critical for controlling metallurgical processes and assessing the environmental impact of mine waste. Accurate quantification enables optimization of metal recovery and monitoring of acid generation potential in residues, waste rock and tailings.

Objectives and Study Overview

This application note demonstrates a rapid and precise method for total carbon and sulfur analysis in ores using the LECO CS844 combustion analyzer. The procedure covers sample preparation, instrument setup, calibration using reference materials and validation across a wide concentration range.

Methodology and Applied Instrumentation

Samples are milled to a uniform powder and dried at 105 °C or corrected to a dry basis. Approximately 0.2 to 0.25 g of sample is combined with a carbon accelerator (LECOCEL series) and iron chip accelerator in a ceramic crucible. The CS844 operates at constant furnace power and features a 10 second purge, 20 second delay and zero cool time. Carbon is released by combustion and sulfur by pyrolysis in an inert atmosphere. Two calibration approaches are used: single standard linear force through origin for low levels and multi point full regression for high levels.

Main Results and Discussion

Analysis of NIST and LECO calibration materials and real ore samples achieved carbon precision within 0.02 percent RSD and sulfur precision within 0.01 percent RSD. Measured values closely matched certified values over a range of 0.15 to 11.5 percent for carbon and 0.52 to 11.1 percent for sulfur. The method exhibited excellent linearity and minimal drift after calibration.

Benefits and Practical Applications

• Fast analysis time under one minute per sample to support high throughput.
• Wide dynamic range suitable for trace to high concentration measurements.
• High accuracy and precision ensure reliable metallurgical accounting.
• Simple sample preparation with standard drying and sieving.

Future Trends and Potential Applications

Future developments may focus on automated sample handling to further increase throughput and integration with process data systems for real time monitoring. Advances in detector design could improve sensitivity for ultra trace carbon and sulfur levels. The method may expand into environmental monitoring of mine tailings and waste rock to support sustainability goals.

Conclusion

The LECO CS844 combustion method provides a robust solution for accurate carbon and sulfur determination in metal bearing ores. Its speed, precision and broad analytical range meet the demands of mining laboratories for process control, quality assurance and environmental compliance.

Reference

ASTM E1915 Standard Test Method for Carbon and Sulfur in Ores and Related Materials by Combustion