| Abstract: | All investigations made in the course of the present inquiry aimed at developing proposals for the optimisation of blast furnace bottom and hearth refractories by means of experimental tests. Furthermore, the tests are intended to develop new solutions for prolongation campaign life of blast furnace linings by applying the finite-element method. In the model calculations, particularly those bricks having a high thermal conductivity, showed high resistance to crack and spall formation. In comparison to standard or microporous grades, graphite containing carbon blocks lower the risk of tensile cracks. By additionally doping graphite containing grades with aluminium oxide and silicon, high resistance against pig iron dissolution and infiltration can be reached. Metallurgical coke content proved disadvantageous in the brick, because due to its high porosity the content can be infiltrated additionally into the porous binding matrix. Reduced flow in the brickwork and, thus, reduced convective heat transfer lead to reduced tensile levels in the brickwork. By adapting the pool depth and tap hole length, particularly the linings in the bottom and tap hole area will be relieved thermically. In addition to the required stability of coke particle size and its large particle diameter to ensure an equally distributed pig iron flow through the dead man, the dead man should also have good carburization capacities. When comparing the dissolving inclination by temperature reduction at the internal hearth wall side to the doping influence, it becomes clear that wear can be reduced much more efficiently by adding aluminium oxide than by increasing cooling measures. |
