Rotary kilns in cement work have been evaluated for a wide variety of organic wastes such as wood, used tyres, plastic waste, etc. Therefore, although ASR has some chlorine, its use as fuel in rotary kilns has been recognized as an effective method for ASR treatment to recover energy resources. The aim of this paper is to present the results of computational fluid dynamic (CFD) modeling applied to a cement works precalciner for ASR use as an alternative fuel. The work was done using the commercial CFD code FLUENT which was used to solve the steady state, three dimensional, fully viscous Navier Stokes equations. The effects of the mutual interactions between ASR chips and coal were simulated by discrete phase modeling approach, while ASR and coal combustion was simulated by the finite rate devolatilization models. The pseudo calcination reaction of CaCO3 was also used in this work.