Real time sensing of temperature and chemistry in molten metal - CONSE

Good process control is crucial for quality, efficiency and safety in the production and processing of metal. However, developing measurement systems for this environment is a challenge. High temperatures and a corrosive and dirty atmosphere put high demands on the sensor systems to be used.

A typical metallurgical process today monitors the temperature using thermocouples, in this case a disposable sensor. The chemical composition is typically studied using sampling and chemical analysis in a laboratory. Both of these measurement methods provide a snapshot of temperature and material composition at the time and place where the sample was taken. No information is given about variations in temperature and composition over time and over the melt.

The ability to continuously, and in real time, monitor these parameters is of great interest in the metallurgical industry. Continuous real-time measurements of temperature and chemical composition in molten metal could contribute to higher efficiency (eg lower energy consumption, lower raw material consumption), better steel quality, higher safety and could possibly also enable a higher use of recycled materials in the processes.

RISE and partners have previously developed systems for continuous monitoring of temperature and chemistry, specially adapted for metallurgical processes.

Continuous temperature measurement: BST (Broad Band Spectral Thermometry) is a method where process radiation from the melt is collected and its optical spectrum analyzed to determine the process temperature. The principle is the same as for pyrometers, but with the important difference that BST analyzes a wide optical spectrum, which makes the technology considerably more robust, and enables measurements in environments and processes where pyrometers cannot be used. BST can also provide other important information from the process, such as the presence of alkalis. By using fiber optics, the process radiation can be collected directly from the process. Read more about BST. 

Continuous analysis of chemical composition: LIBS is a well-established method for analyzing chemical content in materials. A high-energy laser pulse is fired at the material to be analyzed. The laser light creates a local plasma where the content of the material is revealed by specific lines in the plasma spectrum. Read more about LIBS.

In this project, the next step was taken towards the commercialization of these measurement systems. Internationally leading metallurgical industry, Zanardi (Italy) and Sandvik Materials (Sweden, now Alleima), test the systems in their metallurgical processes and Agellis (now part of RHI Magnesita), a Swedish measurement technology company with leading solutions for the metallurgical industry, validates the commercial potential.

This project received funding from EIT RawMaterials, initiated and funded by the European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation.