Title

THE APPLICATION OF ON-LINE GAS ANALYSIS BY MASS SPECTROMETRY TO SECONDARY STEEL MAKING

THE APPLICATION OF ON-LINE GAS ANALYSIS BY MASS SPECTROMETRY TO SECONDARY STEEL MAKING

Authorship

Traynor, Peter; Wright, Robert

Traynor, Peter

I am this author

Wright, Robert

I am this author

DOI

10.5151/2594-5300-18114

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Abstract

This paper describes how fast on-line gas analysis by Process Mass Spectrometry is used in secondary steel production forbetter process control and end-point determination to reduce costs and product variability and to expedite process- turnaround. Process Mass Spectrometry is a very powerful analytical technique, providing very accurate and rapid multi-component analysis. Modern instruments are compact, low maintenance and very reliable even in the relatively harsh environment near a steel making furnace. Mass Spectrometry has been successfully applied to Argon Oxygen Decarburization (AOD), Vacuum Oxygen Decarburization (VOD) and Ruhrstahl-Hausen (RH) furnaces. In the AOD process, gas analysis is utilized to control the argon/nitrogen/oxygen mixtures used to decarburize the steel whilst minimising the undesirable oxidation of chromium. Measurements of evolved CO and CO2 are used to determine the process end-point. In RH and VOD the process occurs under vacuum and mass spectrometry is easily adapted to these conditions as it is itself a vacuum technique. Decarburization end-point is more accurately determined. Mass spectrometry can measure all components in the off-gas: H2, CO, N2, O2, Ar and CO2. Additionally it can be used to monitor a tracer gas such as helium for calculating the extent of decarburization. As well as describing the benefits of using on-line gas analysis by Process Mass Spectrometry, this paper also describes the principles of the technique and discusses some of the installation considerations, such as gas sample conditioning, calibration requirements and data communications.

This paper describes how fast on-line gas analysis by Process Mass Spectrometry is used in secondary steel production forbetter process control and end-point determination to reduce costs and product variability and to expedite process- turnaround. Process Mass Spectrometry is a very powerful analytical technique, providing very accurate and rapid multi-component analysis. Modern instruments are compact, low maintenance and very reliable even in the relatively harsh environment near a steel making furnace. Mass Spectrometry has been successfully applied to Argon Oxygen Decarburization (AOD), Vacuum Oxygen Decarburization (VOD) and Ruhrstahl-Hausen (RH) furnaces. In the AOD process, gas analysis is utilized to control the argon/nitrogen/oxygen mixtures used to decarburize the steel whilst minimising the undesirable oxidation of chromium. Measurements of evolved CO and CO2 are used to determine the process end-point. In RH and VOD the process occurs under vacuum and mass spectrometry is easily adapted to these conditions as it is itself a vacuum technique. Decarburization end-point is more accurately determined. Mass spectrometry can measure all components in the off-gas: H2, CO, N2, O2, Ar and CO2. Additionally it can be used to monitor a tracer gas such as helium for calculating the extent of decarburization. As well as describing the benefits of using on-line gas analysis by Process Mass Spectrometry, this paper also describes the principles of the technique and discusses some of the installation considerations, such as gas sample conditioning, calibration requirements and data communications.

Keywords

Mass spectrometer; Process optimization.

Mass spectrometer; Process optimization.