To verify the engineering application value of low melting point quaternary mixed nitrate molten salt

the quaternary mixed nitrate molten salt with low melting point

high decomposition temperature and low cost developed by our research group

and two pilot tests on ton-scale engineering application were carried out. Subsequently

the thermal physical properties were tested at different elevated temperatures

and the melting point

initial crystal point

decomposition temperature and other parameters at different heating temperatures were obtained. After that

the molten salt was analyzed by scanning electron microscopy

X-ray diffraction and ion chromatography. The results show that the melting point of industrial low melting point quaternary mixed nitrate is 89.77 ℃

the initial crystal point is 151.46 ℃

and the decomposition temperature is 616.2 ℃. Under air atmosphere

the conversion of nitrite ions to nitrate ions and the continuous decomposition of calcium nitrate are the main reason for the increase of melting point and initial crystal point of the molten salt system at different elevated temperatures. In the high temperature section

the melting point and the initial crystal point did not change much

indicating that the molten salt had good thermal stability under high temperature conditions.