Continuous feeding of the raw meal with the right composition is essential for product quality and for optimal and efficient operation of the kiln system.  This requires precise adjustment of the mixing ratios of different raw materials based on careful analysis of their chemical composition and the analysis of the raw meal.  This can be achieved by the use of an online automatic control system. One such system combines continuous measuring equipment, an automatic sampler, an X-ray fluorescence spectrometer of the glass bead method, and a computer program for mixing control.