Blast furnace burden quality: laboratory simulation

Laboratory simulations have been set up, based on vertical probings in the blast furnace at different radial positions. With this simulation, it is possible to investigate the behaviour of ferrous burden and coke under the conditions prevailing inside the blast furnace. Pellets and sinter have been tested for reducibility, reduction disintegration, swelling, shrinking, and bed permeability. Microscopic examination of reduced samples helped to understand the results. To the wustite stage, pellets are reduced faster than sinter, owing to their higher porosity. Reduction disintegration is greater for sinter than for pellets. Sinter disintegration consists mainly of breakage, pellet disintegration mainly of abrasion. Reduction of wustite proceeds slower for pellets. The explanation can be found in the formation of a dense iron layer at the surface of the pellets. (C) 1997 The Institute of Materials.