Effects of temperature and oxygen potential on removal of sulfur from desulfurization slag

Akitoshi Matsui, Yu Ichi Uchida, Naoki Kikuchi, Yuji Miki

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15 Citations (Scopus)


The effects of temperature (1 373-1 673 K) and oxygen potential on removal of sulfur from hot metal desulfurization slag were investigated in laboratory-scale experiments. Both CaS and CaSO4 exist as sulfur compounds in hot metal desulfurization slag. CaS can be removed under the condition of higher oxygen potential, whereas CaSO4 can be removed at a lower oxygen potential. Thus, in order to remove both CaS and CaSO4 from desulfurization slag, it is important to control the temperature and oxygen potential to the optimum values. In this study, a higher sulfur removal ratio exceeding 90% was obtained under the conditions of a temperature range of 1 473-1 673 K and oxygen potential range of 10-3-10-8 atm. These results were in good agreement with thermodynamic calculations. In order to confirm the possibility of reusing desulfurization slag as flux after sulfur removal, hot metal desulfurization experiments were carried out with a 70 kg-scale laboratory furnace. At the same CaO amount in the desulfurization flux, [S] content at 900 seconds after flux addition was approximately equal to that when using virgin flux. The effect of SiO2 contamination due to slag recycling on the desulfurization rate constant K was also estimated. From these experimental results, it may be suggested that removal of sulfur from desulfurization slag is an effective approach for constructing a slag recycling system.

Original languageEnglish
Pages (from-to)1012-1018
Number of pages7
JournalIsij International
Issue number6
Publication statusPublished - 2017
Externally publishedYes


  • Desulfurization slag
  • Hot metal pretreatment
  • Slag recycle

ASJC Scopus subject areas

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


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