FURTHER APPLICATION OF THE GENERIC GROSS ERROR DETECTION AND DATA RECONCILIATION SYSTEM FOR ALUMINA REFINERY DIGESTION PROCESS
Further to the successful application of the model-based generic gross error detection (GED) and data reconciliation system to the alumina evaporation process, reported in the last AQW conference (Lee et al, 2012), this paper presents the extension of the system for the Bayer digestion process. The system, implemented at a number of Alcoa-operated refineries, has been demonstrated to be able to not only detect field instrument errors and provide reconciled process and laboratory readings to site engineers, but also to provide soft sensors for unmeasured key parameters. The reconciled readings of the field instruments such as bauxite slurry, liquor flow meters, heater temperature meters and blow-off ratio are available to the plant area engineers and instrument maintenance staff via customised manufacturing execution system (MES) visualisation on a regular schedule. Examples provided in this paper demonstrate the capability of the GED system to address process and instrument issues within the building.