Study on Risk Evaluation of Hydroxylamine/water Solution

Abstract

In order to find the cause of explosive fire which occurred in Japan in June 2000[ 1 ]?the decomposition hazards of hydroxylamine(HA) solution were studied experimentally. The thermal decomposition of HA solution was evaluated from calorimetric data obtained using deferential thermal analysis (DTA). The magnitude of the intensity of decomposition was investigated on the basis of the results of the mini closed pressure vessel test (MCPVT) and the pressure vessel test (PVT), the steel tube test and the burning test of HA. The thermal analysis was conducted to evaluate the ease of thermal decomposition of the HA solution. The heating onset temperatures using the stainless steel cells were reduced more than 70 ?C compared with those measured using the gold-coated stainless steel cells. Therefore the heating onset temperature depended on the materials of sample cell. On the other hand, the heat of reaction did not depend on the materials of sample cell. The decomposition reaction of HA solution was enhanced due to the catalytic effect of iron ion came from the stainless steel surface. Burning test of mixture of HA and iron ion supported these data. Sudden fire was made when 85 % of HA and iron was mixed. These data were compared with APTAC data by Cisneros et al.[2] and it was found both data gave good agreement regarding the heating onset temperature. The MCPVT, the PVT and the steel tube test were conducted for the purpose of evaluating the magnitude of the intensity of the thermal decomposition when HA solution decomposed. The intensity of the thermal decomposition of HA increased when the HA concentration reached 70 %. In addition, HA 85 % solution was easily detonated by a small detonator.