One of the methods of thermodynamic stabilization of AN (ammonium nitrate) crystals, which is currently used not only as nitrogen fertilizer, but also as an environmentally friendly oxidant for gas-generating fuels for various purposes, is the technology of obtaining low-defect crystal structures. It is known that the potassium ion is a phase stabilizer of AN, and chlorine-containing compounds affect the rate of thermal decomposition of AN; therefore, there has been made an attempt to use a modifier, which includes both elements: potassium salt of monochloroacetic acid (PMCHAA) and to study its effect on phase transitions and thermal decomposition of AN depending on the amount of additive, type of solvent and crystallization temperature. As a result of the tests, it has been found out that a sample containing 1% PMCHAA (obtained at 80 ° C from an aqueous medium) most fully meets the requirements for EnCS oxidizers: the rate of thermal decomposition of the sample is 2.65 times higher than that of AN crystals recrystallized under the same conditions; the rate of modification transition IV – III has been reduced by almost 3 times

Keywords: ammonium nitrate, oxidizer, gas-generating compositions, polymorphic transition, thermal decomposition, additive, kinetics, thermodynamics, potassium salt of monochloroacetic acid, solvent, co-crystallization

In the article are introduced research results of physicochemical properties of ammonium nitrate – potassium nitrate water system at 25o C. The literary source analysis is performed that no clear opinion about solid phases composition. The different composition double salts, solid solution and eutectics are identifies. Appeal is specifies a look and properties of formed structures. Methods of differential thermal analysis and X-ray diffraction have been establishing that the equilibrium solid phase of the studied system represents two types of solid solutions. A first type based on the III phase of ammonium nitrate crystal latitude (at the content of nitrate of potassium to 20 %) and a second type based on the potassium nitrate rhombic syngony (at the content of nitrate of potassium more than 80 %). Crystal cells parameters of being formed phases submit to the Vegard rule. The ammonium nitrate sample (at the content of nitrate of potassium more than 12 %) keeps phase stability at the temperature range minus 50 to plus 100о С. Burst in components miscibility at the potassium nitrate concentration range 30 to 80 % is observed.

Keywords: ammonium nitrate, potassium nitrate, differential thermal analysis, X-ray diffraction, cocrystallization, solid solution

The results of differential thermal analysis of ammonium purpurate-ammonium nitrate system have been presented. The samples have been obtained of melt method. At the contents of ammonium purpurate more than 1 % in samples turn up replacement sequence of ammonium nitrate polymorphic transitions has been established.

Keywords: ammonium nitrate, ammonium purpurate , phase stable, gas-generating composition