Recycling effects of residual slag after magnetic separation for phosphorus recovery from hot metal dephosphorization slag

Research output: Contribution to journalArticlepeer-review

50 Citations (Scopus)


In a previous study, the authors found that phosphorus exhibits remarkable segregations in industrial hot metal pretreatment slag where it exists as a Ca3P2O8-Ca2SiO4 solid solution together with a FeOCaO-SiO2-MnO-MgO matrix. Since the magnetic property of each phase is significantly different, it is possible to separate the phases with the aid of a superconducting strong magnetic field. By applying a strong magnetic field of 0.5 to 2.5 T to the crushed slag, more than 60% of the concentrated phosphorus phase in the slag was recovered. If most of the phosphorus can be removed from the slag, the residual slag will comprise FeO-CaO-SiO2-MnO-MgO with less P2O5, and thus may be recycled to iron- and steel-making processes, such as sintering, hot-metal desiliconization, and hot-metal dephosphorization processes. In the present work, the recycling effect of subjecting the residual slag to the dephosphorization process was simulated based on a mass balance calculation. A significant reduction in total slag generation and CaO input was demonstrated by the mathematical model considering phosphorus recovery and recycling of residual slag as a dephosphorization agent. Using the waste input-output model, it was shown that phosphorus recovery from dephosphorization slag and the recycling of residual slag in a hot-metal dephosphorization process have potentially great environmental and economic benefits.

Original languageEnglish
Pages (from-to)65-70
Number of pages6
JournalIsij International
Issue number1
Publication statusPublished - 2010


  • Dephosphorization
  • Hot metal pretreatment
  • Multi-phase flux
  • Slag recycling
  • Waste input-output analysis

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


Dive into the research topics of 'Recycling effects of residual slag after magnetic separation for phosphorus recovery from hot metal dephosphorization slag'. Together they form a unique fingerprint.

Cite this