Abstract: A method and apparatus for controlling cement clinker production uses a detection device disposed proximate to the feed end of a rotary cement kiln to detect the chemical analysis of a combined additive/kiln feed mixture. A controller changes the feed rate of the additive feeder to adjust for differences between the detected chemical composition and a chemical target specification such as tricalcium silicate, tricalcium aluminate, lime saturation, silica ratio or aluminum to iron ratio. The timely and convenient adjustment of kiln feed chemistry provides more uniform kiln feed chemistry resulting in better kiln operation in terms of productivity, fuel efficiency and less refractory wear. This method and apparatus can provide chemical adjustments for different grades of clinker.