Admixing Hydrocarbons in Raw Mix to Reduce NOx Emission in Iron Ore Sintering Process

Abstract

The traditional de-NOx processes in iron ore sinter plants, power plants or in refineries is to treat the waste gas by the Selective Catalytic Reduction (SCR) process or Selective Non-Catalytic Reduction (SNCR) process which removes the nitrogen oxides from the flue gas. Space and huge capital requirements are needed for installing of such de-NOx facilities. This study takes a different approach, aiming at reducing the formation of NOx during sintering rather than treating the waste gases. Our preliminary experimental findings showed that NO was drastically decreased by introducing hydrocarbons into the sinter mix. Rice husk and sugar had the potential to improve the sinter bed permeability and shorten the high temperature duration time in the combustion zone. The encouraging results showed that the NOx concentration was decreased from 223 to 160 ppm, or emission was decreased from 533.8 g/t sinter to 283.3 g/t sinter by 1 % sugar addition and the productivity was increased from 37.5 to 45.4 t/m²/24 h. The sinter qualities of Tumbler Index (ISO+6.3 mm%) was kept the same, the RDI was improved from 31.5 to 27.3 %.