Abstract:Dissolution behavior of CaF2 and its impacts on magnesium aggregation in NaCl-KCl-MgCl2 melt were investigated by XRD and gas-cooled cathode. The results show that CaCl2 and MgF2 are obtained through reaction between MgCl2 and CaF2 in melts. Concentration of fluoride and calcium ions gradually rises with increase of CaF2 addition, but increment of fluoride ions is slower than that of calcium ions. Mg2OFCl and Mg2OF2 are produced via reaction of CaF2 with MgO, which reduces influence of magnesium aggregation by MgO, and magnesium presents laminated structure in cathode. Surface tension of melts gradually drops with increasing addition of CaF2 due to formation of CaCl2.