Fundamental study of Sn removal from hot metal by NH3Gas blowing

Naotaka Sasaki, Yu Ichi Uchida, Yu Ji Miki, Hidetoshi Matsuno

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Development of a practical method of Sn removal in the steelmaking process is necessary from the viewpoints of promoting use of scrap procured in the market and reducing energy consumption. It is well known that Sn promotes surface cracks of billets in hot rolling by coexisting with Cu. Although various methods of Sn removal have been investigated in laboratory experiments, enough Sn removal efficiency for commercially use has not been obtained. In the present study, Sn removal from high-S hot metal by NH3gas blowing was investigated in laboratory experiments as a new method of Sn removal. The laboratory experiment on Sn removal from hot metal was carried out using up to a 10 kg-scale vacuum induction melting furnace. Sn removal was accelerated while blowing NH3 gas, and the evolution of gas bubbles were observed at the hot metal surface. Within the ranges of these experiments, higher temperature and higher concentrations of S and N were advantageous for Sn removal. The mechanism of the acceleration of Sn removal by NH3gas blowing could be estimated that oversaturated N or H in hot metal made small bubbles to increase the hot metal surface for SnS evaporation. In the estimation of Sn removal ratio in plant-scale operation, it could reach 40%. For further rapid Sn removal, it was necessary to maximize [N] of hot metal by optimizing the lance height or flow rate of NH3gas.

Original languageEnglish
Pages (from-to)1807-1812
Number of pages6
JournalIsij International
Issue number8
Publication statusPublished - 2014
Externally publishedYes


  • Detinning
  • Hot metal pretreatment
  • NH3 gas
  • Vacuum processing

ASJC Scopus subject areas

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


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