The article is devoted to developing a mathematical models of the sintering processes of calcnepheline and firing the cement mixture in a tubular rotary kilns based chain curtains. Chain curtains are installed in a rotary kilns for the intensification of heat exchange between the material and burn the gas flow, drying material, dust and carbon capture. The influence of chain curtains on the processes of heat transfer and dust separation are investigated. The developed equations allow to describe these processes in a mathematical model of a tubular rotary kiln. The resulting mathematical model of sintering and firing is implemented in software package ReactOp.