Model of the state of the blast furnace hearth

A model for estimation of erosion and skull profiles of the blast furnace h earth is presented. The model, which is based on thermocouple measurements in the hearth bottom and wall lining, estimates the most severe erosion of the lining experienced during the campaign and also the present thickness o f the skull material. The model is illustrated on process data from two Fin nish blast furnaces. Complementary measurements and calculations are used t o verify the results. Based on the findings, conclusions are drawn about th e internal state of the blast furnace hearth, for instance whether the dead man floats or sits at the bottom. Finally, some suggestions on how to cont rol the state of the furnace hearth are given.