Effect of Al2O3 Content in Slag on Blast Furnace Permeability and Drainage of Tapping

摘要

Permeability and drainage of tapping are affected by slag fluidity in blast furnace operations.Increasing Al2O3 content in the slag tend to cause troubles in operation such as excess accumulation of molten slag in the furnace hearth and increase of pressure drop at the lower part of the furnace.In this study,in order to clarify the effect of the fluidity of the high Al2O3 slag on blast furnace operations.,high Al2O3 slag (20 ％) test operations of the experimental blast furnace have been carried out.Investigation results of the test operations are as follows.1) Permeability of the cohesive zone is improved by increasing MgO and decreasing CaO/SiO2 of iron-ore at high Al2O3 iron-ore.2) Permeability of the dripping zone is improved by decreasing CaO/SiO2 of slag at high Al2O3 slag operation of the blast furnace.3) MgO in slag improves the hearth drainage rate at high Al2O3 slag operation.