Abstract: Rate data were collected for calcinations during cement production for 4 years at the same time intervals. The amount of CaCO3 consumed in tons was plotted against time in minutes. The plots gave good numerical fit (R2>0.99) for all the model equations studied but the parameter estimates for K, CAO and n varied widely (>5%) for all rate equations except the rate equation for zero order reaction which has an average rate constant of 1.41275 tons min-1 and an average percentage deviation of 3%. Calcination is a zero order reaction based on the equation, CAO-CA = Kt with an average reaction rate constant of 1.41275 tons min-1. This rate model will serve as a basis for the design of rotary kiln for calcinations processes. The model equation obtained from this research may also be used to simulate and optimize processes for cement production.