We have faced the serious coating formation at 12 to 26 meter of Kiln and plant have to be forced stopped for coating removal. I am attaching the three files for your observations:
1. photograph of the Kiln coating.
2. Observation about the breakdown.
3. Analysis data for coating, Rawmix and coal.

I may request you to please look into the coating formation details and furnish us your valuable comments.

I would recommend using the glueing method rather than screw jacks and then you can replace as long a section as you like without the concern of installing and removing the jacks. My understanding is that the glueing method will have no problems with a kiln of 3.95m diameter. However, you would be better to check this with suppliers of the refractory glue when placing your order.

Our clinker chemical composition is as follows: SiO₂= 21 per cent; Ca_O= 64 per cent; Al₂O₃ = 6.0 per cent; Fe₂O₃= 5.2 ; K₂O = 0.4 per cent; SO₃ = 0.55 per cent; MgO =1.0 per cent; Free CaO = 1.0 per cent and the liquid = 34.5 per cent. Liter Wt 1380g/ l. If there is slight reduction in the liquid the clinker becomes dusty though the free CaO is under control. Here it seems the Al₂O₃ comes from limestone does not get into liquid though the calculated liquid is high.If slight reduction in Fe₂O₃ content results in dusty clinker. We add aluminous laterite and hematite ore as fluxes. The question is how to differentiate between the actual liquid and calculated liquid.Does the optical microscopy help in this regard? From your experience give a clear picture on how to reduce the liquid content with improved nodulisation and to have better refractory life in the burning zone. Even the Spinel bricks give only( refra mag-85 of refratecnik) six month's life.

I'm surprised that a rise from 0.07 to 0.12 per cent sulphur in the raw mix causes upset conditions. These are low values compared to many kilns whose companies add much more in the petroleum coke they use to fire their kilns. The sodium carbonate will dissociate in the kiln and the Na₂O will combine with the sulphur (as sodium sulphate) and pass out in the clinker. Your strategy is sound and based on known principles of the alkali cycle. There is no doubt that alkali penetration is one potential cause of refractory failure but at the levels you are using there should be no problem. There is wealth of material on the alkali cycle. The best reference I know is S.Sprung, "Technological problems in pyroprocessing cement clinker: cause & solution" published by Beton-Verlag.