Burning of hydroxylammonium nitrate

Burning of solid crystalline hydroxylammonium nitrate (HAN) and its water solutions is studied in a constant-pressure bomb within the pressure range from 0.1 to 36 MPa. Abnormally high pressure exponents are found to be typical of combustion of the crystalline substance, its $\approx$ 9-mole/liter water solution, and a solution containing ethanolamine nitrate as a fuel: for pressures below $\approx$ 10 MPa, the burning rate is proportional to the 1.5–2.6 power of pressure. Crystalline HAN retains this tendency up to $\approx$ 20 MPa, whereas the solutions burning in the turbulent regime show a sharp decrease in the pressure exponent if the pressure exceeds 10 MPa. In some instances, as was found in previous works, the burning rate even decreases with increasing pressure. Special features of turbulent burning are explained. A model is proposed to describe the steady-state burning of solid HAN. Kinetic parameters of the leading reaction are derived.