You are correct the theoretical liquid content of your clinker is very high. The litre weight is also high indicating a very dense (almost fused) clinker. Some Al₂O₃ will undoubtedly be taken into solid solution in the alite phase. Optical microscopy can indeed tell you the true liquid content (and the true alite, belite and free CaO content). There are photographic and computer pattern recognition systems available that will do this for you and eliminate the variation between microscopists. With regard to refractory life the liquid content and its properties are important. The viscosity of the flux is a critical consideration. Too fluid a flux can lead to dusting. These inter-relationships are very complex. To answer your questions properly would require a full and detailed process investigation involving microscopic analysis of frequent samples coupled with detailed process data over an extended period.

How can we reduce the clinker size -5mm >35 per cent (existing), we want to reduce to under 20 per cent. Our plant is a 1Mta capacity unit. Fuel is petcoke 70 per cent balance Indian coal.

The only way to change the clinker size will be to change the kiln feed chemistry or the operation of the kiln. To have less fines in the clinker you should try to increase the flux content by reducing the silica modulus. Alternatively adjust the rotational speed of the kiln by slowing slightly to increase the residence time.

What is the emissivity of a kiln's shell? I ask this because i need to know it to take infrared thermography of the surface shell of a kiln.