A new study published in Nature Scientific Reports shows significant advances in the refining process of Fe-Si (ferrosilicon) alloys, which are crucial for steel production. A team of researchers led by Tomasz Merder from the Silesian University of Technology demonstrates the successful application of a novel gas injection technique using a system of nozzles installed at the bottom of the refining ladle.
Removal of unwanted carbon and aluminium content
In the process, the gas is injected from the bottom of the ladle by a combination of bottom and top blowing (using a lance). This technique is in contrast to conventional methods, where gas is injected from the top only, and aims to achieve a more uniform chemical and thermal homogenisation of the liquid alloy.
The main objective of the research work was to optimise the position and configuration of the purge plug and the combined blowing systems to improve the removal of impurities. The removal of unwanted carbon and aluminium content is crucial for the production of high-purity steel.
It has been shown that the specific placement and design of the nozzles can significantly influence the distribution and size of the gas bubbles in the molten metal, which in turn affects the refining performance.
Experimental tests and industrial validation
The approach was analysed in experimental tests using a 1:3 scale physical model and validated under industrial conditions.
The experiments were carried out with a ladle capacity of 3 cubic metres and corresponded to the gas flow rates of 26.8 litres per minute previously used in industry.
Potential and effects of the improved blowing processes
Combined blowing processes, using both lance and purge plugs, have great potential to significantly improve the quality of the FeSi75 alloy and make it cleaner and more uniform. The success of the process in reducing impurities in the alloy has potential implications for improving the overall quality of steel products and reducing manufacturing costs.
The research provided insights into the dynamics of gas bubble behaviour in the liquid metal and showed the effects of different bubble configurations on the homogenisation of the alloy. In addition, the team's approach not only promises to increase production efficiency, but also supports the industry's move towards more sustainable and cost-effective manufacturing processes.
Merder, T., Kozłowski, S., Pieprzyca, J. et al. (2024) Physical modelling of two-phase liquid-gas processes occurring in the refining ladle for Fe-Si alloy refining process. Sci Rep 14, 17565. DOI:10.1038/s41598-024-68501-9
