Raw material preparation and sintering method for reducing NOx emission in iron ore sintering

Raw material preparation and sintering method for reducing NOx emission in iron ore sintering

  • CN 107,287,414 B
  • Filed: 06/07/2017
  • Issued: 08/14/2020
  • Est. Priority Date: 06/07/2017
  • Status: Active Grant
First Claim
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1. Reduction of iron ore sintering NOxThe discharged raw material preparation method is characterized by comprising the following steps:

  • step 1, weighing iron ore powder, fuel and flux according to mass ratio;

    dividing iron ore powder into an iron ore powder I and an iron ore powder II according to the mass ratio;

    2, pelletizing the first iron ore powder to prepare a first mother ball;

    step 3, uniformly mixing the iron ore powder II and a flux to prepare adhesive powder;

    step 4, pelletizing the adhesive powder and the first mother ball in a disc pelletizer under the condition of spraying atomized water to prepare a second mother ball;

    step 5, uniformly mixing the coke powder and the mother ball II to obtain NO for reducing iron ore sinteringxThe discharged raw material;

    in the step 1, the iron ore powder, the fuel and the flux are respectively in the following mass ratio;

    75-85% of iron ore powder, 5-8% of fuel and 10-20% of flux;

    the fuel is coke powder, and the flux is dolomite, limestone and quicklime;

    in the step 1, the mass ratio of the iron ore powder I to the iron ore powder II is 0.6-1.5;

    in the step 2, pelletizing the iron ore powder I in a disc pelletizer, adding atomized water in the pelletizing process, and taking the manufactured pellets as mother pellets I, wherein the total mass of the atomized water is 3-4% of the total mass of the iron ore powder, the fuel and the flux;

    pelletizing for 3-5 min, wherein the radius of the disc pelletizer is 2-3 m, the rotating speed is 5-6 r/min, the inclination angle is 45-50 degrees, and the mass of the prepared primary pellets with the diameter of 2-5 mm accounts for 50-70% of the total mass of the primary pellets;

    in the step 3, uniformly mixing the iron ore powder II and the flux in a cylindrical mixer to prepare adhesive powder;

    the mixing time of the iron ore powder II and the flux is controlled to be 1.5-3 min, and the rotating speed isWherein R is the radius of the cylindrical mixer and the unit is m;

    taking the uniformly mixed iron ore powder II and a flux as adhesive powder;

    in the step 4, the total mass of the atomized water is 4-6% of the total mass of the iron ore powder, the fuel and the flux;

    pelletizing time is controlled to be 6-8 min, the radius of the disc pelletizer is 3-4 m, the rotating speed is 6-7 r/min, the inclination angle is 45-53 degrees, and the mass of the prepared mother ball II with the diameter of 5-8 mm accounts for 60-80% of the total mass of the mother ball II;

    in the step 5, the mixing time of the coke powder and the second mother ball is controlled to be 2.5-3 min, and the rotating speed isWherein R is the radius of the cylindrical mixer and the unit is m.

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