Description
Thermo- and electrochemical processes acting as a source of electromotive forces (EMF) in the lower part of the blast furnace (BF) have been recognized for a long time. Based on voltage acquisition at the outer furnace shell, prior research proposed the use of the EMF-transient to indirectly monitor the liquid phase content in the furnace hearth. In our investigation the amplitude and shape of the EMF signal during the tapping cycle turns out to be strongly dependent on furnace operation. Oxide melt experiments and electric potential measurements are performed in lab-scale crucibles and used together with the furnace derived EMF transients to clarify the source of the EMF signal. A model for the charge separation is developed, based on the electronic and ionic conductors involved in the redox reactions near the interfaces between hot metal, slag, solid carbon and gas phase. For model verification, the resulting resistivity network model is compared to the measured voltage response of a high temperature model cell. EMF signals at the BF are monitored at several circumferential positions on the outer steel shell and the signal-based model prediction is implemented in the process control as a melt level indicator. During tapping the drop of the melt level typically declines with increasing distance from the tap hole. The fine-structure of the EMF signal during the tapping cycle provides detailed insight into the drainage behavior and dead man dynamics.| Period | 1 Jul 2025 → 2 Jul 2026 |
|---|---|
| Event title | 19. Minisymposium der Verfahrenstechnik |
| Event type | Conference |
| Location | MCI Innsbruck, AustriaShow on map |
| Degree of Recognition | National |
Keywords
- blast furnace
- galvanic cell
- electromotive force
- timeseries
- tapping cycles