Innovative Use of Lime for Slag Control in LD

Slag has multiple purposes in LD including protecting the refractory lining and removing impurities such as sulphur and phosphorus from the hot metal. Different chemical reactions taking place during the process, lead to continuous changes in slag composition. Since the slag has multiple functions in LD, the demands on slag also change in different stages of the process.

In this context the Slaggkontroll I project has aimed to meet the industrial challenges in improving the slag formation process, slag control, and final slag quality to minimize lining wear meanwhile more slag can be recycled.

“It's always exciting to be a part of a successful project such as Slaggkontroll I and i am glad on our achievements on developing booster lime-based briquettes with promising quality from chemical, mechanical and metallurgical characteristics for slag control in LD”, says Elsayed Mousa, Project manager from Swerim. “The developed lime-based briquettes are not only necessary for controlling the slag formation in the LD, but it can significantly contribute to the internal recirculation of residual materials in the steel plant which will reflected on increasing the resource efficiency, reducing the environmental impact and boosting the circular economy”, says Magnus Heintz, Senior researcher at Swerim.

“We successfully achieved about 100 full-scale trials at our LD converter in Luleå and we used the unique slag sampler equipment which has been developed by our project partner Mekinor. The samples were selected and analyzed and the achieved results in long run will strengthen our competitiveness through increased understanding of slag formation as well as reduced costs and environmental impact”, says Mats Andersson, Process Engineer at SSAB Luleå.

”I am proud to be a leader of this successful “Slaggkontroll I” project with experts from research institute such as Swerim and professionals from industry such as SSAB EMEA and Mekinor in addition to a great contribution from Jernkontoret. In this project ~100 full-scale trials have been conducted at SSAB LD converter in Luleå where samples were selected and analyzed. The generated results provide a completely unique information on sampling and analysis of slag it gives new description of the initial slag formation in the LD process. These great achievements promote us to move forward to next stage with Slaggkontroll II, thanks to Vinnova for funding this project (2018-2021) and all of project partners and members”, says Fredrik Engström, Project Coordinator and Associate Professor at Luleå University of Technology.

Contacts

Elsayed Mousa, Swerim, elsayed.mousa@swerim.se

Fredrik Engström, Luleå University of Technology, fredrik.i.engstrom@ltu.se