Improvement of hearth drainage efficiency and refractory life for high BF productivity and well-adjusted reductant injection rate at varying coke quality (Hearth efficiency) : final report

A new deadman (DM) porosity and position criterion was developed using bottom temperature and tapping data. This was established online at industrial plants. The ultrasound technique AU-E seems promising to assist with conventional wear determination. Copper was successfully established for hearth tracing tests to replace radioactive materials. Refractory samples from industrial BFs at campaign end were analysed. The aging influences depend on BF operation and refractory. Feed coke and DM core-drill coke symplex were analysed with various methods. The differences were assigned to BF charging and way of operation. Hearth samples from industrial and experimental BFs at campaign ends were analysed. The correlation between BF operation and brittle layer formation was determined using historic BF data. The influence of DM permeability on the hearth drainage was studied via simulation models. Different hearth drainage and tapping conditions were studied experimentally, numerically and by comparison with industrial tracing test results. EBF simulations were performed to investigate raceway combustion and hearth flow. Tapping models were developed based on image processing, EMF, data classification or two-phase flow. They show the effect of hearth and liquid states on drainage. New techniques were developed for the online measurement of HM temperature in runners and accurate hearth liquid level prediction. Temperature and mechanical stresses of BF hearth refractory were modelled using FEM. Approaches with different commercial FEM tools were compared and consistent results were obtained. The influences of different model assumptions were determined. New concepts were introduced to reduce stresses, brittle zones and wear.