Cement is made by heating a mixture of limestone and clay, or other materials of similar bulk composition and sufficient reactivity, to a temperature in the neighbourhood of 1450 °C. Alternate raw materials and alternate fuels are used in cement kilns to reduce production costs. Alkali compounds, Sulphur and Chlorine are introduced in the system by the raw meal constituents. As a result, the OPC chemistry cannot simply be defined by CaO - Al2O3 - Fe2O3 - SiO2 system. Rather the impact of minor constituents like MgO, TiO2, K2O, Na2O, SO3, Chloride etc. need to be considered for cement production process as well as their influence on the refractory performance. “Build Up” is one of the major issues in this unit and the situation is likely to worsen with the increase of Alternate Fuel usage. The volatile compounds, i. e. alkali Sulfates and chlorides, once formed by virtue of reaction between the Alternate Fuel (AF) combustion yield, travel with the flue gas. Sulphur compounds have relatively higher melting points and as a result travel towards the kiln outlet and get recirculated. Chloride compounds, on the other hand, have lower melting points and they are primarily in the inlet area of the kiln. During this study, samples, from different sections of the kiln system, were collected and analysed to understand the root cause of coating build up and refractory failure in various sections of the kiln. Based on these results compatible refractories have been recommended.