PSP-BOF – Removal of Phosphorus from BOF-slag

Initial situation

• Increased cost for raw materials and for landfilling have forced European steelmakers to look for new ways to recycle slag internally in the steel plant or in external applications.
• The significant amount of slag generated result in serious environmental issues and resource losses.

Working topics

• Selection of suitable slags, definition targets for products
• Development of cooling strategy for BOF slag
• Separation of treated slag into products, i.e. in [P-poor + Fe-rich] and [Fe-poor + P-rich] slag fractions. Transfer into industrial scale
• Set up of an oxygen test bay for an indirect slag treatment
• Indirect slag treatment at the oxygen test bay and cold slag processing, i.e. grinding and separation, to produce suitable slag fractions
• Application and investigation of the industrial produced [P-poor + Fe-rich] slag fraction as sinter feed at sinter pot trials as well as the [Fe-poor + P-rich] slag fractions as fertilizer

Results

• Separate phosphorus from BOF-slag and use as a fertilizer for agriculture and farm production
• Remaining slag will be used by internal recycling via sinter plant/blast furnace