There is a lot of data published on alkali bypasses in cement kilns. A good source of information is "Technological problems in pyroprocessing cement clinker: cause and solution", by S Sprung of the Research Institute of the German cement industry, and published by Beton-Verlag. The way to determine the percentage of bypass is to construct a computer model of the particular kiln process and use this model to evaluate scenarios with different percentages of bypass.

How can we solve the nose ring formation at the kiln? Any help much appreciated.

The most likely solution will be to adjust the main burner of the kiln either by changing the position in the kiln by pushing the burner in or pulling it out a little. Alternatively adjustment of the axial and radial air settings might solve the problem. All these adjustments should be done cautiously and one at a time at sufficient intervals to fully evaluate the effects of the adjustments. There is potential to adversely affect the clinker quality or damage the refractory lining therefore only make small changes before evaluating the effects.

We wish to know about oxygen enrichment in the cement kilns/precalciners. Please brief us about the expected merits and demerits. Are there any cement plants using this technique? If yes, then why is it not used commercially on regular basis in most of the cement plants.