Liquid Salts

The University of Wisconsin - Madison has done a considerable amount of work researching various liquid salts for energy transport systems. Included in these salts are fluoride salts (FLiNak, LiF-NaF-KF (46.5-11.5-42 at %)), magnesium chloride salts (MgCl2-KCl eutectic mixture (32-68 at%) and nitrate salts (NaNO3-KNO3 (40-60 wt%), LiNO3-NaNO3-KNO3 (30-52-18 wt%). Through this work we have conducted several studies to:

  • Determine the best methods of small scale salt production and purification
  • Understand corrosion rates of different alloys and materials exposed to the salts for long durations (100-1000 hours) in a static system
  • Study the exposure of the materials in flowing systems (1500 hours)
  • Gather measurements and semi-empirical predictions of the thermal-physical properties of the salts (ρ,cp,μ,k, thermal decomposition, melting point, crystallization point, speed of sound, etc.)
  • Study the reaction rates with water and different hydrocarbons
  • Create tests and models to characterize the heat transfer
  • Understand operational issues with respect to the use of the different salts.

Most of the work to date was conducted with lower melting temperature nitrate salts, however considerable work has also been conducted with the higher melting temperature fluoride and chloride salts. This report summarizes some of the lessons learned in each of these areas.

Details of the specific measurements and findings are presented in a series of additional reports prepared by the University of Wisconsin for the DOE and industrial partners.