Use of ultra violet induced photoluminescence for on-line control of calciners, especially lime kilns

摘要

Quality for calcined products is controlled by photo-luminescence measurements, in which the calcined material is illuminated to excite luminescent emission, the photo-luminescence is measured , either as full spectral emission or as individual spectral bands, and the measurements are compared, at intervals, with reference extinction curves. The illuminant radiation may be in the lower UV range, and the measured luminescence in the upper UV range. Trace elements, especially Rare Earth metals within the mineral crystal lattice, are receptive to short-wave excitation from UV radiation of less than 330 nm , and emit photoluminescence in the 330-440 nm wavelength range.