Analysis of Effectiveness of Bottom Stirring after the Modernization on Basic Oxygen Furnace in HBIS Serbia Group

Abstract

The significant modernization effort in the steel shop at HBIS Group Serbia is the introduction of a Basic Oxygen Furnace, which features bottom stirring with argon and nitrogen, along with the capability for slag splashing with nitrogen through the lance tip after steel tapping from the converter. Implementing this new technology presented a challenge, as it was our first encounter with such advancements. The primary objectives of this modernization were to achieve a lower dissolved oxygen content in steel while reaching the targeted carbon level at the end of the blowing process. This aims to optimize the steel's oxidation degree [%C] [%O], reduce the use of Al as a deoxidizer, increase yield, and achieve a low phosphorus content in steel at the end of blowing. Additionally, it aimed to increase the lining's lifetime through slag splashing and decrease the refractory mass consumption needed for lining repairs. This analysis covers a 7-month period since the start of the campaign with the new refractory lining, based on research conducted on 3,150 heats. Our examination of the process led us to conclude that while certain parameters met our expectations, some results did not reach the anticipated level.