This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR). these are not used to control the kiln until now. in addition robustness criteria are evaluated (gain margin. https://www.ealisboa.com/best-offer-Duraflex-Circuit-Widebody-Fender-Flares-Fiberglass-Infiniti-G35-Coupe-Non-Sport-super-save/