A steady-state model of the rotary kiln used for calcination of basic ammonium aluminum sulfate In production of aluminum oxide Is described. Carrying away of solid particles by gas stream and chokes In the inner kiln wall are specific features of the kiln considered. The model consists of a set of ordinary differential equations describing reaction kinetics and mass and heat balances, a set of algebraic equations for space-depending parameters, and a set of two-point boundary conditions. An algorithm for a numerical solution of the model equations with two point boundary conditions is described along with a method for computation of the kiln with and without chokes. Computational results for the kiln with and without chokes are presented, and a comparison of computed and experimental data for a kiln with chokes Is given.