Optimisation of the slag formation in a blast furnace charged with 100% pellets

Sammanfattning: This work is based on experiences from industrial blast furnaces. Process irregularities when testing self-fluxed pellets Process disturbances when charging increased proportions of coarse pellets Laboratory tests to evaluate the effect of basic fluxes on the slag formation in the bosh and in the raceway have been carried out. Pilot scale tests have been performed to verify the effect of coarse pellets. The effect of reduction degree and the reduction behaviour on the slag formation and blast furnace performance have been evaluated It was found that decreased degree of reduction of pellets or lowly reduced core of coarse pellets decrease the melting temperature and increase the softening and melting temperature interval. Basic fluxes have a negative effect on the melting properties of the self-fluxed pellets and a positive effect on the melting properties of the olivine pellets. Basic fluxes have a positive effect on the melting properties of tuyere slags.