Abstract Dead burning of magnesite in rotary kiln is an energy intensive process. Besides the energy consumed by the magnesite, the heat expenditures are through different areas of the process, such as kiln shell, exit gases, clinker exit, dust etc. The heat loss through the kiln shell by radiation and convection amounts to be a great proportion of the total heat loss in the process. The present work was devoted to the evaluation and assessment of the heat loss through radiation and convection in the process. The work comprises of data acquisition and utilization of the same for the evaluation and assessment of the shell heat loss of the kiln which was running for 128th day of its operation.