Fast analysis of slag for process monitoring and recycling (SlagOnline)

Important results from the project

SlagOnline has worked with a previously developed method for slag analysis based on the LIBS technology. The main purpose of the project was to verify parameters that are critical for electric arc furnace (EAF) control. This has worked well as the accuracy in FeO content is about 5wt.% and the basicity has a relative accuracy of 5.7%. Both measurements are in comparison with reference analysis based on XRF, which in turn is subject to uncertainties.

Expected long term effects

Effects occur when the technology is implemented in industry and production times can be shortened, which leads to large energy savings when using the EAF. During the course of the project, a commercial solution from another player has emerged. This focuses on analysis of crushed slag, which is a step forward. However, the biggest gain is seen when analysis of hot slag without sampling can be carried out. The possibilities for using the slag as a secondary raw material also increase as the chemistry of the slag is better known, and if necessary can be adjusted before solidification.

Approach and implementation

The project has utilised a previously developed equipment to investigate the suitability for use in the EAF process where FeO content is high. The most important activities have been the execution of the two industrial trials. These have resulted in observations that cannot be easily achieved in a lab environment. Hot slags have been analysed immediately after sampling. The equipment´s software has been developed so that measurements can be carried out at short intervals. And this way the repeatability of the measurements and the effect of cooling the samples have been studied.