MIREA, a pioneering solution to enhance global smelter production performance
What about having a real-time indication of your anode quality?
This is the promise of MIREA (“Mesure Instantanée de la Résistance Electrique des Anodes” or “on-line automatic anode electrical resistance measurement”).The MIREA project has been initiated by AP Technology™ in 2011. It is based on the fact that the electrical resistance of anodes is recognized as a significant parameter for pot performance as the carbon material contributes to half of the anode assembly voltage drop. Whereas the theoretical aspects were developed directly by the R&D team of AP Technology™, Fives was the natural partner for industrializing the concept. After the lab-scale device was validated, a scale 1 in-line system was designed by Fives and implemented at Aluminerie Alouette for field tests. The machine is fully automatic for 100% characterization of anodes. It can reliably achieve more than one anode measurement per minute (device cycle time plus conveying) and can easily fit in the baked anodes conveyor thanks to its small footprint. Anodes rejected, through proper selection criteria, are diverted to a nearby alternative conveyor for sending them back to the Green Anode Plant. The measurement consists of 28 voltage drop measures per anode: current is passing through the anode as if it was on the pot, by means of retractable current injection probes, a voltage drop map is then acquired (28 samples through 28 electrical sensors distributed all along the anode) and the voltage drop is converted in apparent resistivity map.
Electrically characterizing the anodes has several advantages toward the global smelter performance:
- Preventing electrolysis incident on pots by detecting individual anodes with defects,
- Improving anode forming and baking process by detecting batch defect,
- Enhancing the management of anode consumption on pots thanks to better knowledge of anode ID.
Thus, both potline operation managers and carbon plant managers can benefit from collecting the resistance profile of baked anodes. Thanks to this technology, a new era of baked anode quality control may start, giving the opportunity to further improve anode behavior on pots while reducing specific energy consumption.
MIREA is a straightforward and cost-effective solution. It is also easy to retrofit in existing plants and is simple to operate.