Nonaqueous purification of mixed nitrate heat transfer media

摘要

A nonaqueous, in-line method for removing carbonate and hydroxide contamination from a molten mixed sodium nitrate/potassium nitrate heat transfer salt. The method comprises dissolving a stoichiometric quantity of anhydrous Ca(NO3)2 in the melt whereby an insoluble CaCO3 and Ca(OH)2 precipitate is formed. The precipitate can be removed by settling, filtration or floatation techniques.