Optical Spectroscopy for Process Monitoring and Production Control in Ferrous and Non-Ferrous Industry

摘要

A common feature of most pyrometallurgical processes is the injection of oxygen to remove various kinds and amounts of impurities present in the feed. The degree of success of a specific process step relies critically on control of the instantaneous oxygen potential/oxidation stage, throughout the step as well as upon termination of the step. This will, for instance, determine the distribution of impurities between metal and slag. As long as the operation is perturbation free detailed analysis of all additions and application of advanced models often yield satisfactory control means. However, a pyrometallurgical process is seldom free from disturbances, which reduces the accuracy of the static models and leads to inconsistencies in the operation and variations in the output. Typical disturbances that might cause the process to leave the scheduled route might be uncontrollable changes in quality and quantity of feed, operator interventions and shift changes, timing of cranes, lining wear and accretions etc. The implementation of dynamic control to correct for disturbances and, more generally, for process optimization, requires continuous online information on the actual status of the process. The implementation of sensors for continuous process monitoring, e.g., as regards the instantaneously prevailing oxygen potential or oxidation stage, has been hampered by the highly aggressive environment in smelters. This is where remote-sensing techniques, based on optics and spectroscopy, have proven to form invaluable tools towards the realization of dynamic production control. Since about 15 years Semtech has developed and industrialized a remote-sensing technology, based on optics and spectroscopy, for continuous on-line process monitoring and production control of various pyrometallurgical processes. The presentation will discuss applicability aspects with examples and experiences from installations and tests in ferrous and non-ferrous industry.