Magnitogorsk Iron and Steel Works (MMK) has commissioned a combined inert gas bottom stirring system on all three converters at its oxygen converter shop, with total investment exceeding RUB 4.5 billion.
The project, designed to reduce steel production costs and improve the quality of finished products, was implemented in three stages. The first bottom stirring system was commissioned on converter No. 3 in August 2025, followed by converter No. 1 in December of the same year and converter No. 2 in June 2026.
The commissioning of a new air separation unit (oxygen plant No. 6) in 2025 helped facilitate the project. Pipelines were installed from the unit to supply argon to the oxygen converter shop for use in the bottom stirring process.
The combined bottom stirring technology increased the yield of saleable steel by 5 kg per tonne of steel produced. Metal oxidation levels were reduced by 2%, lowering consumption of ferroalloys and aluminium required to achieve the target chemical composition. Consumption of slag-forming mixtures also decreased by 5 kg per tonne of steel. The technology enables converters to operate with a higher proportion of hot metal without the addition of scrap. The use of sinter as a coolant further reduced total metallic charge consumption by 11.6 kg per tonne of steel. Another important benefit of the introduction of the bottom stirring technology was a reduction in non-metallic inclusions, such as oxygen, resulting in cleaner steel for rolling operations and, ultimately, higher-quality finished products.
The main process equipment, supplied by the Chinese company SDM, includes a bottom stirring system, an automated stirring control system and an automated converter lining profile scanning system. An acoustic slag detection system has also been commissioned, enabling operators to monitor slag levels in the converter during stirring, helping prevent metal and slag ejections. The selection of operating mode and regulation of inert gas flow are performed automatically using a mathematical model, effectively eliminating the risk of human error.