On-line Analysis of Mn Concentration in Molten Steel by Atomic Absorption Spectrometry

Abstract

Synopsis : Manganese is one of the important elements for characterization of steel and its concentration is controlled in a steelmaking process. Recently, manganese ore can be used in a basic oxygen furnace blowing because the amount of slag is drastically reduced. Accordingly, if changes of the manganese concentration can be monitored more rapidly and accurately during the basic oxygen furnace operation, manganese ore can be utilized to control the final component of molten steel instead of expensive manganese alloy. In this work, we focus on the vapor generated naturally from the molten steel and investigated an on-line system for monitoring the manganese concentration applying the principle of an atomic absorption spectrometry. In using a lab-melting furnace, we confirmed good correlation between the absorption ratio (Mn/Fe) and the manganese concentration within 0.2% in the molten steel.

Direct Quantification of Mn Concentration in Molten Steel Utilizing a Wavelength-Variable Laser

“…5,6) Our study has confirmed that the use of a wavelengthvariable laser as the light source allows the dynamic range to be extended approximately more than 100 times. 7) To apply this technique to the measurement of Mn concentration in molten steel, we have attempted to quantify Mn concentration in molten steel using a laboratory melting furnace by directing laser light at the surface of molten steel through an optical fiber.…”

“…Using a Laboratory Melting Furnace 6) 2.1.1. Melting Furnace 5 kg of pure iron containing less than 0.005% Mn was melted in the air atmosphere in a high-frequency induction furnace.…”

“…This variation could be adequately corrected by evaluating the atom-absorption of Fe. 6) The light intensity after absorption is relatively higher when the absorption sensitivity is reduced than when the laser wavelength for the Mn light is in the absorption center, making it possible to keep the S/B ratio high for the radiant light. This allows quantification of Mn concentrations of 1.5% or higher and increases the gradient of the change in absorbance in a high concentration range, which are advantageous in terms of the accuracy of quantification of Mn concentration.…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…It was found that stainless steel did corrode and would contribute to loosening of the steel implant in the body. Ishida and co-workers 12 devised an on-line atomic absorption spectrometer to measure Mn and Fe in the vapour above a basic oxygen furnace used in steel production. Good correlation was reported between the Mn/Fe absorption ratio and the manganese concentration in the melt (within 0.2%) using a laboratory scale furnace.…”