ABSTRACT PERSSON CTS-9417526 The proposed study is an Industry-University Cooperative Research Project between the New Mexico Institute of Mining and Technology and Nelson Brothers Inc. The PIs propose a systematic study of the chemistry of ammonium nitrate (AN) and ammonium nitrate mixed with fuel oil (ANFO) at pressures similar to those encountered during the detonation of solid explosives. The objective is to understand the fundamental mechanisms of reaction occurring in the detonation of these materials and to find additives which will reduce the red smoke thought to contain the oxides of nitrogen, NO, and NO2, that is generated when AN and ANFO are used as explosives especially at high pressures. Three different laboratory experiments will be used to study the decomposition of these energetic materials. These consist of (1) ignition and surface burning by contact with an adiabatically compressed heated inert gas, (2) shock compression by impact with a flyer plate, and (3) detonation of 1 kg charges in a closed chamber. Reaction products will be analyzed by FTIR and GCMS. These laboratory studies will be carried out at New Mexico. Large scale field test at Nelson Brothers Inc., aimed at obtaining more information on the composition of the red clouds, and the testing of the new proposed compositions and blasting methods, will be carried out. Color video and sampling of the product gases will be used and results compared to the conventional explosives.