Cadence Environmental Energy, Michigan City, Ind., and Ash Grove Cement, Kansas, USA, have been assigned a patent (7,959,435) developed by six co-inventors for a "method and apparatus for reducing NO.sub.x emissions in rotary kilns by SNCR."

The co-inventors are Eric R. Hansen, Shawnee, Kan., Kenneth J. Derksen, South Bend, Ind., Kevin Blankenship, Dallas, Walter Parker, Alvarado, Texas, Ralph A. Supelak, Strongsville, Ohio, and James R. Tutt, Texarkana, Texas.

The abstract of the patent published by the U.S. Patent and Trademark Office states: "A method of operating a mineral processing kiln includes introducing a quantity of a selective non-catalytic reduction (SNCR) reducing agent into the kiln. The SNCR reducing agent may be a solid, liquid, or a gas. A mineral processing kiln modified for the implementation of SNCR is also disclosed."